| 1. |
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| 2. |
- Beal, Jacob, et al.
(author)
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Robust estimation of bacterial cell count from optical density
- 2020
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In: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
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Journal article (peer-reviewed)abstract
- Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
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| 3. |
- de Vries, Paul S., et al.
(author)
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Multiancestry Genome-Wide Association Study of Lipid Levels Incorporating Gene-Alcohol Interactions
- 2019
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In: American Journal of Epidemiology. - : Oxford University Press. - 0002-9262 .- 1476-6256. ; 188:6, s. 1033-1054
-
Journal article (peer-reviewed)abstract
- A person's lipid profile is influenced by genetic variants and alcohol consumption, but the contribution of interactions between these exposures has not been studied. We therefore incorporated gene-alcohol interactions into a multiancestry genome-wide association study of levels of high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides. We included 45 studies in stage 1 (genome-wide discovery) and 66 studies in stage 2 (focused follow-up), for a total of 394,584 individuals from 5 ancestry groups. Analyses covered the period July 2014-November 2017. Genetic main effects and interaction effects were jointly assessed by means of a 2-degrees-of-freedom (df) test, and a 1-df test was used to assess the interaction effects alone. Variants at 495 loci were at least suggestively associated (P < 1 x 10(-6)) with lipid levels in stage 1 and were evaluated in stage 2, followed by combined analyses of stage 1 and stage 2. In the combined analysis of stages 1 and 2, a total of 147 independent loci were associated with lipid levels at P < 5 x 10(-8) using 2-df tests, of which 18 were novel. No genome-wide-significant associations were found testing the interaction effect alone. The novel loci included several genes (proprotein convertase subtilisin/kexin type 5 (PCSK5), vascular endothelial growth factor B (VEGFB), and apolipoprotein B mRNA editing enzyme, catalytic polypeptide 1 (APOBEC1) complementation factor (A1CF)) that have a putative role in lipid metabolism on the basis of existing evidence from cellular and experimental models.
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| 4. |
- Liu, Huan, et al.
(author)
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The first human induced pluripotent stem cell line of Kashin–Beck disease reveals involvement of heparan sulfate proteoglycan biosynthesis and PPAR pathway
- 2022
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In: The FEBS Journal. - : John Wiley & Sons. - 1742-464X .- 1742-4658. ; 289:1, s. 279-293
-
Journal article (peer-reviewed)abstract
- OBJECTIVE: Kashin-Beck disease (KBD) is an endemic osteochondropathy. Due to a lack of suitable animal or cellular disease models, the research progress on KBD has been limited. Our goal was to establish the first disease-specific human induced pluripotent stem cells (hiPSCs) cellular disease model of KBD, and to explore its etiology and pathogenesis exploiting transcriptome sequencing.METHODS: HiPSCs were reprogrammed from dermal fibroblasts of two KBD and one healthy control donors via integration-free vectors. Subsequently, hiPSCs were differentiated into chondrocytes through three-week culture. Gene expression profiles in KBD, normal primary chondrocytes and hiPSC-derived chondrocytes were defined by RNA sequencing. A Venn diagram was constructed to show the number of shared differentially expressed genes (DEGs) between KBD and normal. Gene oncology and Kyoto Encyclopedia of Genes and Genomes annotations were performed, and six DEGs were further validated in other individuals by real-time quantitative reverse transcription PCR (RT-qPCR).RESULTS: KBD cellular disease models were successfully established by generation of hiPSC lines. Seventeen consistent and significant DEGs present in all compared groups (KBD and normal) were identified. RT-qPCR validation gave consistent results with the sequencing data. Glycosaminoglycan biosynthesis-heparan sulfate/heparin, PPAR signaling pathway and cell adhesion molecules (CAMs) pathways were identified to be significantly altered in KBD.CONCLUSION: Differentiated chondrocytes deriving from KBD-origin hiPSCs provide the first cellular disease model for etiological studies of KBD. This study also provides new sights into the pathogenesis and etiology of KBD and is likely to inform the development of targeted therapeutics for its treatment.
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| 5. |
- Sun, Huiliang, et al.
(author)
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A monothiophene unit incorporating both fluoro and ester substitution enabling high-performance donor polymers for non-fullerene solar cells with 16.4% efficiency
- 2019
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In: Energy & Environmental Science. - : ROYAL SOC CHEMISTRY. - 1754-5692 .- 1754-5706. ; 12:11, s. 3328-3337
-
Journal article (peer-reviewed)abstract
- Thiophene and its derivatives have been extensively used in organic electronics, particularly in the field of polymer solar cells (PSCs). Significant research efforts have been dedicated to modifying thiophene-based units by attaching electron-donating or withdrawing groups to tune the energy levels of conjugated materials. Herein, we report the design and synthesis of a novel thiophene derivative, FE-T, featuring a monothiophene functionalized with both an electron-withdrawing fluorine atom (F) and an ester group (E). The FE-T unit possesses distinctive advantages of both F and E groups, the synergistic effects of which enable significant downshifting of the energy levels and enhanced aggregation/crystallinity of the resulting organic materials. Shown in this work are a series of polymers obtained by incorporating the FE-T unit into a PM6 polymer to fine-tune the energetics and morphology of this high-performance PSC material. The optimal polymer in the series shows a downshifted HOMO and an improved morphology, leading to a high PCE of 16.4% with a small energy loss (0.53 eV) enabled by the reduced non-radiative energy loss (0.23 eV), which are among the best values reported for non-fullerene PSCs to date. This work shows that the FE-T unit is a promising building block to construct donor polymers for high-performance organic photovoltaic cells.
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| 6. |
- Bandopadhayay, Pratiti, et al.
(author)
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BET Bromodomain Inhibition of MYC-Amplified Medulloblastoma
- 2014
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In: Clinical Cancer Research. - 1078-0432 .- 1557-3265. ; 20:4, s. 912-925
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Journal article (peer-reviewed)abstract
- Purpose:MYC-amplified medulloblastomas are highly lethal tumors. Bromodomain and extraterminal (BET) bromodomain inhibition has recently been shown to suppress MYC-associated transcriptional activity in other cancers. The compound JQ1 inhibits BET bromodomain-containing proteins, including BRD4. Here, we investigate BET bromodomain targeting for the treatment of MYC-amplified medulloblastoma.Experimental Design:We evaluated the effects of genetic and pharmacologic inhibition of BET bromodomains on proliferation, cell cycle, and apoptosis in established and newly generated patient- and genetically engineered mouse model (GEMM)-derived medulloblastoma cell lines and xenografts that harbored amplifications of MYC or MYCN. We also assessed the effect of JQ1 on MYC expression and global MYC-associated transcriptional activity. We assessed the in vivo efficacy of JQ1 in orthotopic xenografts established in immunocompromised mice.Results:Treatment of MYC-amplified medulloblastoma cells with JQ1 decreased cell viability associated with arrest at G1 and apoptosis. We observed downregulation of MYC expression and confirmed the inhibition of MYC-associated transcriptional targets. The exogenous expression of MYC from a retroviral promoter reduced the effect of JQ1 on cell viability, suggesting that attenuated levels of MYC contribute to the functional effects of JQ1. JQ1 significantly prolonged the survival of orthotopic xenograft models of MYC-amplified medulloblastoma (P < 0.001). Xenografts harvested from mice after five doses of JQ1 had reduced the expression of MYC mRNA and a reduced proliferative index.Conclusion:JQ1 suppresses MYC expression and MYC-associated transcriptional activity in medulloblastomas, resulting in an overall decrease in medulloblastoma cell viability. These preclinical findings highlight the promise of BET bromodomain inhibitors as novel agents for MYC-amplified medulloblastoma.
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| 7. |
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| 8. |
- Chen, Yujie, et al.
(author)
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A gradient-distributed liquid-metal hydrogel capable of tunable actuation
- 2021
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In: Chemical Engineering Journal. - : Elsevier BV. - 1385-8947 .- 1873-3212. ; 421, s. 127762-
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Journal article (peer-reviewed)abstract
- Although thermoresponsive hydrogels have numerous applications that range from soft robots, biomedical engineering, and actuators to sensors for artificial muscles, the existing hydrogel actuators undergo only unidirectional deformation under a single thermal stimulus and suffer from slow actuation and unstable interfacial adhesion in multiple layers. Herein, hydrogels containing gradient-distributed polydopamine-coated eutectic gallium-indium (PDA-EGaIn) nanodroplets in a poly(N-isopropylacrylamide) (PNIPAM) matrix and thus featuring a gradient distribution of thermal conductivity and an increased barrier towards water loss are shown to be capable of a rapid and tuneable thermoresponse. Notably, whereas hydrogels with a low content of PDAEGaIn undergo rapid one-way bending under a single thermal (45 degrees C) stimulus, those with a high content of PDAEGaIn undergo sequential bidirectional (bending) actuation. The ability of these hydrogels to undergo fast and tuneable actuation under a single thermal stimulus makes them suitable for use in grab-release instruments and soft robots.
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| 9. |
- Chen, Yujie, et al.
(author)
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Shape-Memory Polymeric Artificial Muscles : Mechanisms, Applications and Challenges
- 2020
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In: Molecules. - : MDPI. - 1431-5157 .- 1420-3049. ; 25:18
-
Research review (peer-reviewed)abstract
- Shape-memory materials are smart materials that can remember an original shape and return to their unique state from a deformed secondary shape in the presence of an appropriate stimulus. This property allows these materials to be used as shape-memory artificial muscles, which form a subclass of artificial muscles. The shape-memory artificial muscles are fabricated from shape-memory polymers (SMPs) by twist insertion, shape fixation via T(m)or T-g, or by liquid crystal elastomers (LCEs). The prepared SMP artificial muscles can be used in a wide range of applications, from biomimetic and soft robotics to actuators, because they can be operated without sophisticated linkage design and can achieve complex final shapes. Recently, significant achievements have been made in fabrication, modelling, and manipulation of SMP-based artificial muscles. This paper presents a review of the recent progress in shape-memory polymer-based artificial muscles. Here we focus on the mechanisms of SMPs, applications of SMPs as artificial muscles, and the challenges they face concerning actuation. While shape-memory behavior has been demonstrated in several stimulated environments, our focus is on thermal-, photo-, and electrical-actuated SMP artificial muscles.
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| 10. |
- Chen, Zhen, et al.
(author)
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Multifunctional conductive hydrogels and their applications as smart wearable devices
- 2021
-
In: Journal of materials chemistry. B. - : Royal Society of Chemistry (RSC). - 2050-750X .- 2050-7518. ; 9:11, s. 2561-2583
-
Research review (peer-reviewed)abstract
- Recently, hydrogekbased conductive materials and their applications as smart wearable devices have been paid tremendous attention due to their high stretchability, flexibility, and excellent biocompatibility. Compared with single functional conductive hydrogels, multifunctional conductive hydrogels are more advantageous to match various demands for practical applications. This review focuses on multifunctional conductive hydrogels applied for smart wearable devices. Representative strategies for conduction of hydrogels are discussed firstly: (1) electronic conduction based on the conductive fillers and (2) ionic conduction based on charged ions. Then, the common and intensive research on multiple functionahties of conductive hydrogels, such as mechanical properties, conductive and sensory properties, anti-freezing and moisturizing properties, and adhesion and self-healing properties is presented. The applications of multifunctional conductive hydrogels such as in human motion sensors, sensory skins, and personal healthcare diagnosis are provided in the third part. Finally, we offer our perspective on open challenges and future areas of interest for multifunctional conductive hydrogels used as smart wearable devices.
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| 11. |
- Dou, Yujie, et al.
(author)
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Reliability of using vegetation optical depth for estimating decadal and interannual carbon dynamics
- 2023
-
In: Remote Sensing of Environment. - : Elsevier BV. - 0034-4257. ; 285
-
Journal article (peer-reviewed)abstract
- Vegetation optical depth (VOD) from satellite passive microwave sensors has enabled monitoring of aboveground biomass carbon dynamics by building a relationship with static carbon maps over space and then applying this relationship to VOD time series. However, uncertainty in this relationship arises from changes in water stress, as VOD is mainly determined by vegetation water content, which varies at diurnal to interannual scales, and depends on changes in both biomass and relative moisture content. Here, we studied the reliability of using VOD from various microwave frequencies and temporal aggregation methods for estimating decadal biomass carbon dynamics at the global scale. We used the VOD diurnal variations to represent the magnitude of vegetation water content buffering caused by climatic variations for a constant amount of dry biomass carbon. This magnitude of VOD diurnal variations was then used to evaluate the likelihood of VOD decadal variations in reflecting decadal dry biomass carbon changes. We found that SMOS-IC L-VOD and LPDR X-VOD can be reliably used to estimate decadal carbon dynamics for 76.7% and 69.9% of the global vegetated land surface, respectively, yet cautious use is warranted for some areas such as the eastern Amazon rainforest. Moreover, the annual VOD aggregated from the 95% percentile of the nighttime VOD retrievals was proved to be the most suitable parameter for estimating decadal biomass carbon dynamics among the temporal aggregation methods. Finally, we validated the use of annual VOD for estimating interannual carbon dynamics by comparing VOD changes between adjacent years against eddy covariance estimations of gross primary production from flux sites over several land cover classes across the globe. Despite the large difference in spatial scales between them, the positive correlation obtained supports the capability of satellite VOD in quantifying interannual carbon dynamics.
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| 12. |
- Guo, Xiong, et al.
(author)
-
Kashin-Beck Disease (KBD)
- 2017
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In: Endemic disease in China. - Beijing : People's Medical Publishing House. - 9787117247139 ; , s. 150-211
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Book chapter (peer-reviewed)
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| 13. |
- He, Xiaoyu, et al.
(author)
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Dual-optimization strategy engineered Ti-based metal-organic framework with Fe active sites for highly-selective CO2 photoreduction to formic acid
- 2023
-
In: Applied Catalysis B. - : Elsevier BV. - 0926-3373 .- 1873-3883. ; 327
-
Journal article (peer-reviewed)abstract
- Increasing CO2 conversion efficiency over metal-organic framework (MOF) based photocatalysts is of great significance to promote the carbon capture and utilization. In this work, a dual-benefit design strategy is deployed in the synthesis of a new two-dimensional Fe/Ti-BPDC MOF photocatalyst with atomically dispersed Fe sites. This catalyst demonstrated an excellent catalytic performance in the visible-light-driven CO2 conversion to HCOOH, achieving a high yield of 703.9 μmol g-1 h-1 at a selectivity greater than 99.7%. This is attributed to the ‘dual-optimization’ achieved by this catalyst to sustain the supply of photogenerated electrons and to effectively activate CO2. Specifically, the Fe/Ti-BPDC catalyst provides a high proportion of effective photogenerated electrons for the CO2 photocatalysis process via a unique electron transfer mechanism. Meanwhile, the strong O/Fe affinity between CO2 and atomically dispersed Fe active sites not only enables a fast CO2 activation, but also dictates the intermediate reaction pathways towards high HCOOH selectivity.
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| 14. |
- He, Yunfei, et al.
(author)
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Sulfated complex metal oxides solid acids with dual Brønsted-Lewis acidic property for production of 5-ethoxymethylfurfural from biomass-derived carbohydrates
- 2022
-
In: Chemical Engineering Journal. - : Elsevier BV. - 1385-8947. ; 429
-
Journal article (peer-reviewed)abstract
- The transformation of aldose-based carbohydrates into 5-ethoxymethylfurfural (EMF) is very challenging as compared to ketose-based carbohydrates, but the formers are more abundant and cheaper. Here, a series of sulfated complex metal oxides were synthesized for the conversion of aldose-based mono-, di-, and poly-saccharides, as well as starchy food waste into EMF. The catalysts were carefully characterized and the results showed that the type and strength of the acid sites were more important than their concentration. It was also shown that the efficiency of these catalysts was significantly affected by the metal species in the catalyst composition and followed the order tetra- > tri- > bi- > mono-component metal oxides based catalyst. Among the prepared catalysts, Zr-Sn-Fe-Al-O-S exhibited superior catalytic activity, with an EMF yield of 33.1% from glucose, and yields ranging from 4.1−26.3% for di-, poly-saccharides and starchy food waste in ethanol/dimethyl sulfoxide solvent system under glucose/catalyst mass ratio of 4. The role of co-solvent in the reaction pathway was also studied. It was found that the predominant reaction pathway for EMF production was closely related to the co-solvent amount. A kinetic model of glucose conversion to EMF was developed and the thermodynamic analysis was performed, the main features of the experimental observations can be described by the model. Zr-Sn-Fe-Al-O-S was reused for four runs without intermediate regeneration steps, showing a slight decay in activity. After reactivation by calcination before the fifth cycle, the catalyst recovered its activity, indicating good reusability and thermal stability.
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| 15. |
- Li, Wenchao, et al.
(author)
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Numerical simulation of carbon steel atmospheric corrosion under varying electrolyte-film thickness and corrosion product porosity
- 2023
-
In: NPJ MATERIALS DEGRADATION. - : Springer Nature. - 2397-2106. ; 7:1
-
Journal article (peer-reviewed)abstract
- A finite element model is developed to study dynamics of atmospheric corrosion of carbon steel, focusing on the influence of thin electrolyte film thickness under varying corrosion product porosity. Calculations have been done to evaluate the impact of electrolyte film thickness and corrosion product porosity on oxygen diffusion path, and the hindrance effect of corrosion products on the metal surface activity. The time evolution of corrosion current density and controlling steps in the corrosion process are explored. When the corrosion products are loose, oxygen diffusion is the dominant controlling step, and the thicker the electrolyte film, the lower the corrosion rate. When they are dense, the corrosion process is controlled by the mixture of oxygen diffusion and the surface discharge. The oxygen diffusion path is determined only by the corrosion product porosity, and therefore the corrosion rate is not affected by the electrolyte film thickness.
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| 16. |
- Liang, Yujie, et al.
(author)
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Seeded growth of WO3 film on FTO substrate with tunable structures for stable electrochromic performance
- 2016
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In: Integrated Ferroelectrics. - : Taylor & Francis. - 1058-4587 .- 1607-8489. ; 173:1, s. 109-116
-
Journal article (peer-reviewed)abstract
- In this work, tungsten trioxide (WO3) film was prepared on FTO-coated glass substrates using a facile hydrothermal method. Detailed studies revealed that a variety of WO3 nanostructures-including nanosheets, nanoflakes, nanocuboids and 3D nanowire flowers could be obtained by tuning the composition of the precursor solution, where the additive ((NH4)(2)C2O4 and CO(NH2)(2)-(NH4)(2)C2O4)) content and solvent composition played important roles in controlling the shape and size of the WO3. These nanostructure films exhibited good electrochromic performance. The transmittance spectra showed that WO3 film displayed 50% and 70% in the range of visible light at the colored and bleached states (S2) and a potential of +/- 1.0V. There is no significant degradation of the electrochromic properties after 1000 continuous coloration/bleaching cycles, making it attractive for practical applications.
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| 17. |
- Liu, Yujie, et al.
(author)
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Semi-empirical treatment of ionophore-assisted ion-transfers in ultrathin membranes coupled to a redox conducting polymer
- 2021
-
In: Electrochimica Acta. - : Elsevier BV. - 0013-4686 .- 1873-3859. ; 388, s. 138634-
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Journal article (peer-reviewed)abstract
- Applying spectroelectrochemistry to all-solid-state electrodes composed of poly(3-octylthiophene) (POT) and an ultrathin ion-selective membrane on top, it is possible to monitor the dynamic charge transfer (CT) in POT when this event is coupled to ion transfers (ITs) promoted by the absence/presence of a se-lective ionophore in the membrane. Herein, we report on a combination of empirical and theoretical ev-idence revealing that different molar ratios of the ionophore and the cation exchanger in the membrane result in the modulation of non-assisted and assisted ITs of different stoichiometries. This occurs upon the same anodic voltammetric scan. The use of the developed theory together with Sigmoidal & minus;Boltzmann fittings of the experimental dynamic absorbance observed in the POT film permits calculating voltammo-grams with different ITs. An easy semi-empirical treatment additionally provides the calculation of bind-ing constants related to the assisted transfers. Furthermore, the approach is suitable for both preferred and non-preferred ions by the ionophore, which additionally leads to the estimation of the selectivity profile of the POT-membrane system. The extra discovery about the number of electrons associated to the CT in the POT film is expected to propitiate further research towards maximizing peak resolution in the voltammetric experiments. In this context, the developed theory would help in future steps to-wards the prediction of voltammetric responses for multi-ionophore membranes backside contacted with new redox materials, prospecting hence new electrodes for multi-ion detection with optimized analytical features.
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| 18. |
- Liu, Yujie, et al.
(author)
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Spectroelectrochemical Evidence of Interconnected Charge and Ion Transfer in Ultrathin Membranes Modulated by a Redox Conducting Polymer
- 2020
-
In: Analytical Chemistry. - : American Chemical Society (ACS). - 0003-2700 .- 1520-6882. ; 92:20, s. 14085-14093
-
Journal article (peer-reviewed)abstract
- Previous publications have demonstrated the tuning of ion-transfer (IT) processes across ion-selective membranes (ISMs) with thicknesses in the nanometer order by modulating the oxidation state of a film of a conducting polymer, such as poly(3-octylthiophene) [POT], that is in back-side contact. Attempts on the theoretical description of this charge transfer (CT)-IT system have considered the Nernst equation for the CT, while there is no empirical evidence confirming this behavior. We present herein the first experimental characterization of the CT in POT films involved in different CT-IT systems. We take advantage of the absorbance change in the POT film while being oxidized, to monitor the CT linked to nonassisted and assisted ITs at the sample-ISM interface, from one to three ionophores, therefore promoting a change in the nature and number of the ITs. The CT is visualized as an independent sigmoid in different potential ranges according to the assigned IT. Herein, we have proposed a simple calculation of the empirical CT utilizing the mathematical Sigmoidal-Boltzmann model. The identification of the physical meaning of the mathematical definition of CT opens up new possibilities for the design of sensors with superior analytical features (mainly in terms of selectivity) and the calculation of apparent binding constants in the ISM.
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| 19. |
- Liu, Yujie, et al.
(author)
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Spectroelectrochemistry with Ultrathin lon-Selective Membranes : Three Distinct Ranges for Analytical Sensing
- 2022
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In: Analytical Chemistry. - : American Chemical Society (ACS). - 0003-2700 .- 1520-6882. ; 94:25, s. 9140-9148
-
Journal article (peer-reviewed)abstract
- We present spectroelectrochemical sensing of the potassium ion (K+) at three very distinct analytical ranges-nanomolar, micromolar, and millimolar-when using the same ion-selective electrode (ISE) but interrogated under various regimes. The ISE is conceived in the all-solid-state format: an ITO glass modified with the conducting polymer poly(3-octylethiophene) (POT) and an ultrathin potassium-selective membrane. The experimental setup is designed to apply a potential in a three-electrode electrochemical cell with the ISE as the working electrode, while dynamic spectral changes in the POT film are simultaneously registered. The POT film is gradually oxidized to POT+, and this process is ultimately linked to K+ transfer at the membrane-sample interface, attending to electroneutrality requirements. The spectroelectrochemistry experiment provides two signals: a voltammetric peak and a transient absorbance response, with the latter of special interest because of its correspondence with the generated charge in the POT and thus with the ionic charge expelled from the membrane. By modifying how the ion analyte (K+ but also others) is initially accumulated into the membrane, we found three ranges of response for the absorbance: 10-950 nM for an accumulation-stripping protocol, 0.5-10 mu M in diffusion-controlled cyclic voltammetry, and 0.5-32 mM with thin-layer cyclic voltammetry. This wide response range is a unique feature, one that is rare to find for a sensor and indeed for any analytical technique. Accordingly, the developed sensor is highly appealing for many analytical applications, especially considering the versatility of samples and ion analytes that may be spotted.
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| 20. |
- Liu, Yujie, 1995-
(author)
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Spectroelectrochemistry with Ultrathin lon-Selective Membranes
- 2023
-
Doctoral thesis (other academic/artistic)abstract
- Rapid and decentralized chemical sensing strategies are highly demanded in contemporary society to monitor ongoing processes relevant to the environment, food analysis, healthcare, sports performance, etc. In this context, ion-selective electrodes (ISEs) based on polymeric membranes have emerged as a promising analytical technique owing to their features of low cost, portability, versatility, and energy efficiency. Despite their undeniable success in potentiometric sensing, the interrogation of such electrodes under dynamic electrochemical techniques opens new horizons. An interesting example is voltammetric ISEs comprising the tandem ultrathin membranes and poly(3-octylthiophene) (POT) as the redox mediator. In these ISEs, ion transfer (IT) processes at the sample-membrane interface can be modulated by the electron transfer (ET) at the underlaying POT film, presenting an interconnected IT-ET system that is promising for various analytical purposes.Conveniently, the UV-Vis absorption spectra of a POT film present clear differences between its oxidized and reduced forms. Accordingly, spectroelectrochemical properties of POT can be dynamically monitored to track the ET in the film, and ultimately the associated IT processes, in voltammetric ISEs. Effectively, the obtained information is valuable from both a theoretical and analytical application point of views. In this regard, this doctoral project focuses on the spectroelectrochemical study of voltammetric ISEs based on ultrathin ion-selective membranes interconnected with POT films.The first chapter provides a general introduction to the concepts involved in this thesis, emphasizing the all-solid-state ISEs, the development of ultrathin membranes working under voltammetric mode, and UV-Vis spectroelectrochemistry. The second chapter describes the experimental details of the thesis. The third chapter, which is composed of four sections, presents the main results of this thesis and the corresponding discussions.More in detail, the first section reports the utilization of spectroelectrochemistry to characterize the correlation between IT and ET processes in voltammetric ISEs. The dynamic absorbance readout unequivocally corresponds to the ET process resulting along the gradual oxidation of POT. The electrochemical signal, whichinvolves dynamically integrated charge, describes in turn the IT process at the membrane-solution interface. The two processes are proved to be totally interconnected, both exhibiting sigmoidal-shaped features that can be described with the mathematical Boltzmann-Sigmoidal model.The second section presents the visualization of ionophore-assisted and nonassisted IT processes along the same voltammetric scan of a voltammetric ISE, using a series of ultrathin membranes rationalized to produce assisted and nonassisted ITs at different degrees. Essentially, the modification of the ionophore/ion exchanger molar ratio in the membrane tunes the nature of the IT peaks (for the analyte binding with ionophore or not). This derives into the easy calculation of important thermodynamic parameters (e.g., selectivity coefficients and binding constants) based on a semi-empirical approach.The third section investigates the analytical application of the interconnected IT-ET processes based on spectroelectrochemistry. Advantageously, by changing the initial accumulation protocol of the analyte into the membrane, three distinct working ranges at millimolar, micromolar, and nanomolar concentration levels can be realized by the same ISE using absorbance-based readout. Notably, this is a very unique performance for an analytical technique.The fourth section explores the possibility of calibration-free sensing based on theinterconnected IT-ET mechanism. Effectively, introducing a thin-layer sample makes it feasible to achieve complete transport of a cation (e.g., potassium) from the sample to the membrane and vice versa through a cyclic voltammetryinterrogation. Importantly, the charge under the IT peak can be directly utilized for calculating the concentration in the sample, precisely knowing the volume in the developed microfluidic cell. This investigation has demonstrated the huge potential of the developed ISEs (integrated in a microfluidic format) towards the realization of calibration-free analytical determinations.
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| 21. |
- Liu, Yujie, et al.
(author)
-
Thin-Layer Potentiometry for Creatinine Detection in Undiluted Human Urine Using Ion-Exchange Membranes as Barriers for Charged Interferences
- 2020
-
In: Analytical Chemistry. - : American Chemical Society (ACS). - 0003-2700 .- 1520-6882. ; 92:4, s. 3315-3323
-
Journal article (peer-reviewed)abstract
- Herein, thin-layer potentiometry combined with ion-exchange membranes as barriers for charged interferences is demonstrated for the analytical detection of creatinine (CRE) in undiluted human urine. Briefly, CRE diffuses through an anion-exchange membrane (AEM) from a sample contained in one fluidic compartment to a second reservoir, containing the enzyme CRE deiminase. There, CRE reacts with the enzyme, and the formation of ammonium is dynamically monitored by potentiometric ammonium-selective electrodes. This analytical concept is integrated into a lab-on-a-chip microfluidic cell that allows for a high sample throughput and the operation under stop-flow mode, which allows CRE to passively diffuse across the AEM. Conveniently, positively charged species (i.e., potassium, sodium, and ammonium, among others) are repelled by the AEM and never reach the ammonium-selective electrodes; thus, possible interference in the response can be avoided. As a result, the dynamic potential response of the electrodes is entirely ascribed to the stoichiometric formation of ammonium. The new CRE biosensor exhibits a Nernstian slope, within a linear range of response from 1 to 50 mM CRE concentration. As expected, the response time (15-60 min) primarily depends on the CRE diffusion across the AEM. CRE analysis in urine samples displayed excellent results, without requiring sample pretreatment (before the introduction of the sample in the microfluidic chip) and with high compatibility with development into a potential point-of-care clinical tool. In an attempt to decrease the analysis time, the presented analytical methodology for CRE detection is translated into an all-solid-state platform, in which the enzyme is immobilized on the surface of the ammonium-selective electrode and with the AEM on top. While more work is necessary in this direction, the CRE sensor appears to be promising for CRE analysis in both urine and blood.
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| 22. |
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| 23. |
- Liu, Yujie, 1995-, et al.
(author)
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Voltammetric Ion-Selective Electrodes in Thin-Layer Samples : Absolute Detection of Ions Using Ultrathin Membranes
- 2024
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In: Analytical Chemistry. - : American Chemical Society (ACS). - 0003-2700 .- 1520-6882. ; 96:3, s. 1147-1155
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Journal article (peer-reviewed)abstract
- Calibration-free sensors are generally understood as analytical tools with no need for calibration apart from the initial one (i.e., after its fabrication). However, an "ideal" and therefore "more restricted" definition of the concept considers that no calibration is necessary at all, with the sensor being capable of directly providing the analyte concentration in the sample. In the electroanalysis field, investigations have been directed to charge-based readouts (i.e., coulometry) that allow for concentration calculation via the Faraday Law: The sample volume must be precisely defined and the absoluteness of the electrochemical process in which the analyte is involved must be ensured (i.e., the analyte in the sample is similar to 100% converted/transported). Herein, we report on the realization of calibration-free coulometric ISEs based on ultrathin ion-selective membranes, which is demonstrated for the detection of potassium ions (K+). In essence, the K+ transfer at the membrane-sample interface is modulated by the oxidation state of the conducting polymer underlying the membrane. The accumulation/release of K+ to/from the membrane is an absolute process owing to the confinement of the sample to a thin-layer domain (thickness of <100 mu m). The capacity of the membrane expressed in charge is fixed to ca. 18 mu C, and this dictates the detection of micromolar levels of K+ present in ca. 5 mu L sample volume. The system is interrogated with cyclic voltammetry to obtain peaks related to the K+ transfer that can be treated charge-wise. The conceptual and technical innovative steps developed here made the calibration-free detection of K+ possible in artificial and real samples with acceptable accuracy (<10% difference compared with the results obtained from a current-based calibration and ion chromatography). The charge-based analysis does not depend on temperature and appeared to be repetitive, reproducible, and reversible in the concentration range from 1 to 37.5 mu M, with an average coulometry efficiency of 96%.
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| 24. |
- Ning, Yujie, et al.
(author)
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Comparative analysis of the gut microbiota composition between knee osteoarthritis and Kashin-Beck disease in Northwest China
- 2022
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In: Arthritis Research & Therapy. - : BioMed Central. - 1478-6362. ; 24:1
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Journal article (peer-reviewed)abstract
- Background: Osteoarthritis (OA) and Kashin-Beck disease (KBD) both are two severe osteochondral disorders. In this study, we aimed to compare the gut microbiota structure between OA and KBD patients.Methods: Fecal samples collected from OA and KBD patients were used to characterize the gut microbiota using 16S rDNA gene sequencing. To identify whether gut microbial changes at the species level are associated with the genes or functions of the gut bacteria between OA and KBD groups, metagenomic sequencing of fecal samples from OA and KBD subjects was performed.Results: The OA group was characterized by elevated Epsilonbacteraeota and Firmicutes levels. A total of 52 genera were identified to be significantly differentially abundant between the two groups. The genera Raoultella, Citrobacter, Flavonifractor, g__Lachnospiraceae_UCG-004, and Burkholderia-Caballeronia-Paraburkholderia were more abundant in the OA group. The KBD group was characterized by higher Prevotella_9, Lactobacillus, Coprococcus_2, Senegalimassilia, and Holdemanella. The metagenomic sequencing showed that the Subdoligranulum_sp._APC924/74, Streptococcus_parasanguinis, and Streptococcus_salivarius were significantly increased in abundance in the OA group compared to those in the KBD group, and the species Prevotella_copri, Prevotella_sp._CAG:386, and Prevotella_stercorea were significantly decreased in abundance in the OA group compared to those in the KBD group by using metagenomic sequencing.Conclusion: Our study provides a comprehensive landscape of the gut microbiota between OA and KBD patients and provides clues for better understanding the mechanisms underlying the pathogenesis of OA and KBD.
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| 25. |
- Ning, Yujie, et al.
(author)
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Genetic Variants and Protein Alterations of Selenium- and T-2 Toxin-Responsive Genes Are Associated With Chondrocytic Damage in Endemic Osteoarthropathy
- 2022
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In: Frontiers in Genetics. - : Frontiers Media S.A.. - 1664-8021. ; 12
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Journal article (peer-reviewed)abstract
- The mechanism of environmental factors in Kashin-Beck disease (KBD) remains unknown. We aimed to identify single nucleotide polymorphisms (SNPs) and protein alterations of selenium- and T-2 toxin-responsive genes to provide new evidence of chondrocytic damage in KBD. This study sampled the cubital venous blood of 258 subjects including 129 sex-matched KBD patients and 129 healthy controls for SNP detection. We applied an additive model, a dominant model, and a recessive model to identify significant SNPs. We then used the Comparative Toxicogenomics Database (CTD) to select selenium- and T-2 toxin-responsive genes with the candidate SNP loci. Finally, immunohistochemistry was applied to verify the protein expression of candidate genes in knee cartilage obtained from 15 subjects including 5 KBD, 5 osteoarthritis (OA), and 5 healthy controls. Forty-nine SNPs were genotyped in the current study. The C allele of rs6494629 was less frequent in KBD than in the controls (OR = 0.63, p = 0.011). Based on the CTD database, PPARG, ADAM12, IL6, SMAD3, and TIMP2 were identified to interact with selenium, sodium selenite, and T-2 toxin. KBD was found to be significantly associated with rs12629751 of PPARG (additive model: OR = 0.46, p = 0.012; dominant model: OR = 0.45, p = 0.049; recessive model: OR = 0.18, p = 0.018), rs1871054 of ADAM12 (dominant model: OR = 2.19, p = 0.022), rs1800796 of IL6 (dominant model: OR = 0.30, p = 0.003), rs6494629 of SMAD3 (additive model: OR = 0.65, p = 0.019; dominant model: OR = 0.52, p = 0.012), and rs4789936 of TIMP2 (recessive model: OR = 5.90, p = 0.024). Immunohistochemistry verified significantly upregulated PPARG, ADAM12, SMAD3, and TIMP2 in KBD compared with OA and normal controls (p < 0.05). Genetic polymorphisms of PPARG, ADAM12, SMAD3, and TIMP2 may contribute to the risk of KBD. These genes could promote the pathogenesis of KBD by disturbing ECM homeostasis.
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| 26. |
- Pérez Ràfols, Clara, et al.
(author)
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Why Not Glycine Electrochemical Biosensors?
- 2020
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In: Sensors. - : MDPI AG. - 1424-8220. ; 20:14
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Journal article (peer-reviewed)abstract
- Glycine monitoring is gaining importance as a biomarker in clinical analysis due to its involvement in multiple physiological functions, which results in glycine being one of the most analyzed biomolecules for diagnostics. This growing demand requires faster and more reliable, while affordable, analytical methods that can replace the current gold standard for glycine detection, which is based on sample extraction with subsequent use of liquid chromatography or fluorometric kits for its quantification in centralized laboratories. This work discusses electrochemical sensors and biosensors as an alternative option, focusing on their potential application for glycine determination in blood, urine, and cerebrospinal fluid, the three most widely used matrices for glycine analysis with clinical meaning. For electrochemical sensors, voltammetry/amperometry is the preferred readout (10 of the 13 papers collected in this review) and metal-based redox mediator modification is the predominant approach for electrode fabrication (11 of the 13 papers). However, none of the reported electrochemical sensors fulfill the requirements for direct analysis of biological fluids, most of them lacking appropriate selectivity, linear range of response, and/or capability of measuring at physiological conditions. Enhanced selectivity has been recently reported using biosensors (with an enzyme element in the electrode design), although this is still a very incipient approach. Currently, despite the benefits of electrochemistry, only optical biosensors have been successfully reported for glycine detection and, from all the inspected works, it is clear that bioengineering efforts will play a key role in the embellishment of selectivity and storage stability of the sensing element in the sensor.
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| 27. |
- Rehman, Hafeez Ur, et al.
(author)
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High-cycle-life and high-loading copolymer network with potential application as a soft actuator
- 2019
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In: Materials & design. - : ELSEVIER SCI LTD. - 0264-1275 .- 1873-4197. ; 182
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Journal article (peer-reviewed)abstract
- Thermo-responsive polymer materials ate appealing in emerging fields including soft robotics, artificial muscles, and actuators. However, realising a single smart polymer material that can achieve immense strain, fast actuation, and high loading remains a challenge. We attempted to address these limitations by fabricating a thermo-responsive copolymer network structure of poly(urethane-caprolactone-siloxane). The relative concentrations of these precursors were adjusted to realise a high mechanical strength of >= 17 MPa, 100% shape fixation, and a quick shape recovery time of <= 15 s. Experimental results revealed that the soft segments largely determines the extensibility and crystallinity of the copolymer material. The thermal gradient of the soft part enables the copolymer to self-heal during shape recovery. The copolymer network was applied to a load lifting device as an artificial muscle and was able to lift 200 times its weight with a short response time of <5 s and maximum power density that was half that of mammalian skeletal muscles. With its fast actuation, high loading, and self-healing abilities, the developed therrno-activated smart copolymer material is potentially applicable to a wide range of fields such as soft robotics, biomimetic devices, and prosthetics.
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| 28. |
- Rehman, Hafeez Ur, et al.
(author)
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Self-Healing Shape Memory PUPCL Copolymer with High Cycle Life
- 2018
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In: Advanced Functional Materials. - : WILEY-V C H VERLAG GMBH. - 1616-301X .- 1616-3028. ; 28:7
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Journal article (peer-reviewed)abstract
- New polyurethane-based polycaprolactone copolymer networks, with shape recovery properties, are presented here. Once deformed at ambient temperature, they show 100% shape fixation until heated above the melting point, where they recover the initial shape within 22 s. In contrast to current shape memory materials, the new materials do not require deformation at elevated temperature. The stable polymer structure of polyurethane yields a copolymer network that has strength of 10 MPa with an elongation at break of 35%. The copolymer networks are self-healing at a slightly elevated temperature (70 degrees C) without any external force, which is required for existing self-healing materials. This allows for the new materials to have a long life of repeated healing cycles. The presented copolymers show features that are promising for applications as temperature sensors and activating elements.
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| 29. |
- Rehman, Hafeez Ur, et al.
(author)
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Stretchable, Strong, Recyclable Helicide Elastomer Based on Dynamic Covalent Interactions
- 2023
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In: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 15:39, s. 46280-46291
-
Journal article (peer-reviewed)abstract
- Current methods for making and disposing synthetic polymers have been widely pursued and are largely unsustainable. As a part of the solution, the reversible nature of dynamic covalent bonds emerges as an extraordinarily diverse and valuable feature in the development of exotic molecules and extended structures. With these bonds, it should be possible to construct recyclable and mechanically interlocked molecular structures using relatively simple precursors with preorganized geometries. A new helicide-based elastomer network is developed here with self-healing, recycling, and degradation features using a similar concept. The best self-healing performance (100%) was noted over 10-20 min, with various H2O, HCl, and NaOH solutions that delivered mechanical properties in the 1-1.4 MPa range. For hydrolytic degradation, the parameters are defined based on the type of binding, the pH of the solutions, and the copolymer network, which endowed a degradation time of approximately 4-11 h for each prepared sample. However, due to the reversible nature of the dynamic bonds, the material showed good recyclable mechanical properties compared to the pristine samples after five consecutive cycles, which meet the requirements of recyclable materials and recyclable packaging.
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| 30. |
- Sun, Huiliang, et al.
(author)
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Reducing energy loss via tuning energy levels of polymer acceptors for efficient all-polymer solar cells
- 2020
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In: Science China Chemistry. - : Springer Science and Business Media LLC. - 1869-1870 .- 1674-7291. ; 63:12, s. 1785-1792
-
Journal article (peer-reviewed)abstract
- The open-circuit voltage (Voc) of all-polymer solar cells (all-PSCs) is typically lower than 0.9 V even for the most efficient ones. Large energy loss is the main reason for limiting Voc and efficiency of all-PSCs. Herein, through materials design using electron deficient building blocks based on bithiophene imides, the lowest unoccupied molecular orbital (LUMO) energy levels of polymer acceptors can be effectively tuned, which resulted in a reduced energy loss induced by charge generation and recombination loss due to the suppressed charge-transfer (CT) state absorption. Despite a negligible driving force, all-PSC based on the polymer donor and acceptor combination with well-aligned energy levels exhibited efficient charge transfer and achieved an external quantum efficiency over 10% while maintaining a large Voc of 1.02 V, leading to a 9.21% efficiency. Through various spectroscopy approaches, this work sheds light on the mechanism of energy loss in all-PSCs, which paves an avenue to achieving efficient all-PSCs with large Voc and drives the further development of all-PSCs.
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| 31. |
- Sun, Huiliang, et al.
(author)
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Reducing energy lossviatuning energy levels of polymer acceptors for efficient all-polymer solar cells
- 2020
-
In: Science China Chemistry. - : Science China Press and Springer-Verlag GmbH Germany. - 1674-7291 .- 1869-1870. ; 63, s. 1785-1792
-
Journal article (peer-reviewed)abstract
- The open-circuit voltage (V-oc) of all-polymer solar cells (all-PSCs) is typically lower than 0.9 V even for the most efficient ones. Large energy loss is the main reason for limitingV(oc)and efficiency of all-PSCs. Herein, through materials design using electron deficient building blocks based on bithiophene imides, the lowest unoccupied molecular orbital (LUMO) energy levels of polymer acceptors can be effectively tuned, which resulted in a reduced energy loss induced by charge generation and recombination loss due to the suppressed charge-transfer (CT) state absorption. Despite a negligible driving force, all-PSC based on the polymer donor and acceptor combination with well-aligned energy levels exhibited efficient charge transfer and achieved an external quantum efficiency over 10% while maintaining a largeV(oc)of 1.02 V, leading to a 9.21% efficiency. Through various spectroscopy approaches, this work sheds light on the mechanism of energy loss in all-PSCs, which paves an avenue to achieving efficient all-PSCs with largeV(oc)and drives the further development of all-PSCs.
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| 32. |
- Sun, Weiwei, et al.
(author)
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Monodispersed FeS 2 Electrocatalyst Anchored to Nitrogen-Doped Carbon Host for Lithium–Sulfur Batteries
- 2022
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In: Advanced Functional Materials. - : Wiley. - 1616-3028 .- 1616-301X. ; 32:43
-
Journal article (peer-reviewed)abstract
- Despite their high theoretical energy density, lithium–sulfur (Li–S) batteries are hindered by practical challenges including sluggish conversion kinetics and shuttle effect of polysulfides. Here, a nitrogen-doped continuous porous carbon (CPC) host anchoring monodispersed sub-10 nm FeS2 nanoclusters (CPC@FeS2) is reported as an efficient catalytic matrix for sulfur cathode. This host shows strong adsorption of polysulfides, promising the inhibition of polysulfide shuttle and the promoted initial stage of catalytic conversion process. Moreover, fast lithium ion (Li-ion) diffusion and accelerated solid–solid conversion kinetics of Li2S2 to Li2S on CPC@FeS2 host guarantee boosted electrochemical kinetics for conversion process of sulfur species in Li–S cell, which gives a high utilization of sulfur under practical conditions of high loading and low electrolyte/sulfur (E/S) ratio. Therefore, the surfur cathode (S/CPC@FeS2) delivers a high specific capacity of 1459 mAh g−1 at 0.1 C, a stable cycling over 900 cycles with ultralow fading rate of 0.043% per cycle, and an enhanced rate capability compared with cathode only using carbon host. Further demonstration of this cathode in Li–S pouch cell shows a practical energy density of 372 Wh kg−1 with a sulfur loading of 7.1 mg cm−2 and an E/S ratio of 4 µL mg−1.
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| 33. |
- Wang, Hui, et al.
(author)
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Promotion of NH3-SCR activity by sulfate-modification over mesoporous Fe doped CeO2 catalyst : Structure and mechanism
- 2021
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In: Journal of Hazardous Materials. - : ELSEVIER. - 0304-3894 .- 1873-3336. ; 414
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Journal article (peer-reviewed)abstract
- The mesoporous Fe doped CeO2 catalyst after modifying organic sulfate functional groups show an excellent activity with above 80% NOx conversion in a temperature range of 250-450 degrees C. These organic-like sulfate groups bound to the Fe-O-Ce species leads to the strong electron interaction between Fe3+-O-Ce4+ species and sulfate groups, which modifies the acidity and redox properties of catalyst. The strong ability of (SO)-O-=/S-O in sulfate groups to accommodate electrons from a basic molecule is a driving force in the generation of acidic properties, and thus promotes to produce new Bronsted acid sites. The bondage of Fe-O-Ce species obviously inhibits the creation of thermostable bidentate NO3- species. Besides, the redox cycles between Fe3+ and Ce4+ are disrupted, thus inhibiting NH3 oxidation at medium-high temperatures and resulting in the increase of NOx conversion. Furthermore, the in situ DRIFTS results show that for the fresh samples, the coordinate NH3 reacts not only with NO3 through L-H mechanism, but also with oxygen species to form NOx. Differently for sulfated sample, the coordinate NH3 might react with achieved NO2 instead of the oxygen species through E-R mechanism, meanwhile the NH4+ could react with the NO3- species through L-H mechanism.
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| 34. |
- Wang, Kai, et al.
(author)
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Zinc anode based alkaline energy storage system: Recent progress and future perspectives of zinc–silver battery
- 2024
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In: Energy Storage Materials. - 2405-8297. ; 69
-
Research review (peer-reviewed)abstract
- Rechargeable zinc-based batteries have come to the forefront of energy storage field with a surprising pace during last decade due to the advantageous safety, abundance and relatively low cost, making them important supplements of lithium-ion batteries. As a significant role in zinc-based batteries, zinc-silver battery owns the advantages of high specific energy density, stable working voltage, high charging efficiency, safety and environmental friendliness, and it has been widely used in military such as in aerospace, deep water manned and civil field such as energy supply for watch and hearing aid. However, it is still suffering from a few drawbacks such as unsatisfactory cycle life, low utilization of the cathode. This review introduces the basic principles of zinc-silver batteries and elaborates the battery configurations aiming to understand its working mechanisms as well as the related issues. Most importantly, the very recent research updates and the concerns have arisen in the development are summarized from conventional cell to flexible device and hybrid device. Finally, the challenges and perspectives of zinc-silver batteries are further prospected to give a broad idea to readers new in the area and trigger inspirations for motivated researchers to further widen the utilization of silver-zinc batteries.
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| 35. |
- Wang, Qianyu, et al.
(author)
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Electrochemical biosensor for glycine detection in biological fluids
- 2021
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In: Biosensors & bioelectronics. - : Elsevier BV. - 0956-5663 .- 1873-4235. ; 182
-
Journal article (peer-reviewed)abstract
- We present herein the very first amperometric biosensor for the quantitative determination of glycine in diverse biological fluids. The biosensor is based on a novel quinoprotein that catalyzes the oxidation of glycine with high specificity. This process is coupled to the redox conversion of Prussian blue in the presence of hydrogen peroxide originating from the enzymatic reaction. The optimized tailoring of the biosensor design consists of the effective encapsulation of the quinoprotein in a chitosan matrix with the posterior addition of an outer Nafion layer, which is here demonstrated to suppress matrix interference. This is particularly important in the case of ascorbic acid, which is known to influence the redox behavior of the Prussian blue. The analytical performance of the biosensor demonstrates fast response time (<7 s), acceptable reversibility, reproducibility, and stability (<6% variation) as well as a wide linear range of response (25?500 ?M) that covers healthy (and even most unhealthy) physiological levels of glycine in blood/serum, urine and sweat. A total of 6 real samples from healthy patients and animals were analyzed: two serum, two urine and two sweat samples. The results were validated via commercially available fluorescence kit, displaying discrepancy of less than 9% in all the samples. The unique analytical features and effortless preparation of the new glycine biosensor position it at the forefront of current technologies towards decentralized clinical applications and sport performance monitoring.
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| 36. |
- Wu, Cuiyan, et al.
(author)
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Long noncoding RNA expression profile reveals lncRNAs signature associated with extracellular matrix degradation in kashin-beck disease
- 2017
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In: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 7
-
Journal article (peer-reviewed)abstract
- Kashin-Beck disease (KBD) is a deformative, endemic osteochondropathy involving degeneration and necrosis of growth plates and articular cartilage. The pathogenesis of KBD is related to gene expression and regulation mechanisms, but long noncoding RNAs (lncRNAs) in KBD have not been investigated. In this study, we identified 316 up-regulated and 631 down-regulated lncRNAs (≥ 2-fold change) in KBD chondrocytes using microarray analysis, of which more than three-quarters were intergenic lncRNAs and antisense lncRNAs. We also identified 232 up-regulated and 427 down-regulated mRNAs (≥ 2-fold change). A lncRNA-mRNA correlation analysis combined 343 lncRNAs and 292 mRNAs to form 509 coding-noncoding gene co-expression networks (CNC networks). Eleven lncRNAs were predicted to have cis-regulated target genes, including NAV2 (neuron navigator 2), TOX (thymocyte selection-associated high mobility group box), LAMA4 (laminin, alpha 4), and DEPTOR (DEP domain containing mTOR-interacting protein). The differentially expressed mRNAs in KBD significantly contribute to biological events associated with the extracellular matrix. Meanwhile, 34 mRNAs and 55 co-expressed lncRNAs constituted a network that influences the extracellular matrix. In the network, FBLN1 and LAMA 4 were the core genes with the highest significance. These novel findings indicate that lncRNAs may play a role in extracellular matrix destruction in KBD.
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| 37. |
- Xu, Kequan, et al.
(author)
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Ultrathin ion-selective membranes for trace detection of lead, copper and silver ions
- 2022
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In: Electrochimica Acta. - : Elsevier BV. - 0013-4686 .- 1873-3859. ; 427
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Journal article (peer-reviewed)abstract
- Voltammetric ion-selective electrodes (ISEs) based on poly(3-octylthiophene) (POT) in connection with ultra-thin membranes formulated with different selective receptors (i.e., ionophores) are proposed for detection of lead, copper and silver ions (Pb2+, Cu2+ and Ag+). The working mechanism of the POT-membrane electrode is based on interconnected charge transfer processes on both sides of the membrane, with the overall process depending on the electron transfer in the POT lattice ultimately linked to the ion transfer at the membrane–sample interface. This latter is demonstrated to be controlled by (i) the membrane composition and (ii) the accumulation/stripping electrochemical protocol, allowing the detection of traces of Ag+, Pb2+ and Cu2+. In the case of the Pb2+-selective electrode, the voltammogram displays several peaks that are hypothesized to correspond to different ion–ionophore stoichiometries. Following the signal related to the principal stoichiometry (1:1), a Pb2+ concentration as low as 0.1 nM is measurable. In contrast, the Cu2+- and Ag+-selective electrodes show only one peak for the corresponding ion analyte, which can be also detected at nanomolar concentrations. The results obtained with the three electrodes support their further usage for multi-ion detection in water samples through either a multi-ionophore-based electrode or multiple-electrode device. In any case, the membrane composition, in terms of the ionophore/exchanger molar ratio, is key to achieving a successful analytical application. Upcoming efforts may be directed at the replacement of traditional trace metal ion detection with the hanging mercury drop electrode to develop a more sustainable electrochemical approach without diminishing the analytical performance.
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