SENSORS
·
2022
·Vol. 23
·期 1
·353
·
IF 3.847
Rong Zhang,Tiantian Hao,Shihui Hu,Kaiyang Wang,Shuhui Ren,Ziwei Tian,Yunfang Jia
Flexible electrolyte-gated graphene field effect transistors (Eg-GFETs) are widely developed as sensors because of fast response, versatility and low-cost. However, their sensitivities and responding ranges are often altered by different gate voltages. These bias-voltage-induced uncertainties are an obstacle in the development of Eg-GFETs. To shield from this risk, a machine-learning-algorithm-based LgGFETs’ data analyzing method is studied in this work by using Ca2+detection as a proof-of-concept. For the as-prepared Eg-GFET-Ca2+sensors, their transfer and output features are first measured. Then, eight regression models are trained with the use of different machine learning algorithms, including linear regression, support vector machine, decision tree and random forest, etc. Then, the optimized model is obtained with the random-forest-method-treated transfer curves. Finally, the proposed method is applied to determine Ca2+concentration in a calibration-free way, and it is found that the relation between the estimated and real Ca2+concentrations is close-to y = x. Accordingly, we think the proposed method may not only provide an accurate result but also simplify the traditional calibration step in using Eg-GFET sensors.Keywords:electrolyte-gated graphene field effect transistor;Ca2+detection;machine learning;regression model;calibration-free;flexible
研究领域:
材料科学
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纳米技术
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生物传感器
·
机器学习
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF LUMINESCENCE
·
2020
·
IF 3.28
Hao Tang,Hua Zhou,Xianhua Cheng
The green and red upconversion (UC) emissions of 35 mol% Ca 2+ doped β-NaYF 4 :Yb 3+ /Er 3+ microcrystals were improved to 102.8 and 43.1 times higher than those of Ca 2+ -free counterparts. X-ray powder diffraction spectra, scanning electron microscopy, Fourier transform infrared spectroscopy , upconversion luminescence (UCL) spectroscopy and Judd-Ofelt analysis were performed to investigate the mechanism of UCL intensity enhancement caused by Ca 2+ doping. The hexagonal-to-cubic phase transition was observed when Ca 2+ doping concentration exceeded 35 mol%. The incorporation of Ca 2+ into hexagonal microcrystals lattice induced unit cell volume enhancement and microcrystals surface to volume ratio variation, which affected the UCL intensity by hindering the non-radiative energy loss process via Yb 3+ /Er 3+ ions and changing the amount of surface quenchers adsorbed on the microcrystals surface. The hypersensitive transition related local crystal field asymmetry around Er 3+ in the grown hexagonal microcrystals was also investigated by Judd-Ofelt analysis but unexpectedly found to be the less dominant factor for the UCL intensity variation. This study helps to realize the mechanism of impurity ion doping resulted UCL intensity enhancement, which is instructive for high-performance UC microcrystals synthesis.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2025
·
IF 8.5
Shenglong Shang,Yu Zheng,Luyao Wei,Jie Liu,Ping Zhu
Green and low carbon development has become an unstoppable mainstream of the global and forced a trend of developing biomass fibers with high performance. Alginate fiber is an important component of marine biobased fibers that has gained widespread interest recently. However, applications of alginate fiber are facing challenges because of its limited mechanical properties. Here, we developed a novel design to prepare structurally enhanced alginate fibers alginate fiber by constructing multiple Ca 2+ crosslinked and interpenetrating networks in alginate chains. Through the synergistic effect of two biocompatible polymers, the entanglement of alginate chains was improved and the viscosity was controlled at a certain level which would not affect the fiber forming. The as-spun alginate fibers without further stretching possess a breaking strength of 265.7 MPa, elongation at break of 19.6 %, outperforming most alginate fibers enhanced by adding reinforcement additives. Improving the intermolecular entanglement to enhance the mechanical properties paves a new way for fabricating high-performance alginate fibers.
研究领域:
生物材料
·
高分子科学
·
纤维素化学
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生物医学工程
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绿色化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF CHEMICAL PHYSICS
·
2023
·Vol. 158
·期 23
·
IF 4.4
Yu Yi,Shao Kai,Niu Chonghui,Dan Mingjie,Wang Zhibin,Wang Yingying,Chen Jie,Luo Jiani,Liu Shiying,Xie Zhi
Mn-based phosphors with the wavelength of 700–750 nm are an important category of far-red phosphors that have promising potential in the application of plant lighting, and the higher ability of the far-red light emitting of the phosphors is beneficial to plant growth. Herein, a series of Mn 4+ - and Mn 4+ /Ca 2+ -doped double perovskite SrGd 2 Al 2 O 7 red-emitting phosphors with wavelengths centered at about 709 nm were successfully synthesized by means of a traditional high-temperature solid-state method. First-principles calculations were conducted to explore the intrinsic electronic structure of SrGd 2 Al 2 O 7 for a better understanding of the luminescence behavior in this material. Extensive analysis demonstrates that the introduction of Ca 2+ ions into the SrGd 2 Al 2 O 7 :Mn 4+ phosphor has significantly boosted the emission intensity, internal quantum efficiency, and thermal stability by 170%, 173.4%, and 113.7%, respectively, which are superior to those of most other Mn 4+ -based far-red phosphors. The mechanism of the concentration quench effect and the positive effect of co-doping Ca 2+ ions in the phosphor were extensively explored. All studies suggest that the SrGd 2 Al 2 O 7 :0.1%Mn 4+ , 11%Ca 2+ phosphor is a novel phosphor that can be used to effectively promote the growth of plants and regulate the flowering cycle. Therefore, promising applications can be anticipated from this new phosphor.
研究领域:
材料科学
·
植物学
·
光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
LIFE SCIENCES
·
2024
·
IF 5.2
Fang Chen,Huyan Shen,Gang Liu,Pingping Zhang,Lin Zhang,Siyu Lin,Han Gao,Hong Peng,Yan-Fei Qi,Yan Chen,Yinhui Jiang,Jiandong Huang,Xiangchun Shen,Yu-Si Luo,Ke Zhang
Aims The study evaluated the antiviral effect of Verapamil against respiratory syncytial virus (RSV) and investigated its underlying mechanism. Materials and methods RSV-infected BALB/c mice were treated with Verapamil. Body weight, survival rates, viral load, lung damage, inflammatory factors, and the expression of RSV fusion (F) protein were analyzed. In cellular studies, intracellular Ca 2+ and viral titers were measured in the presence of Verapamil, Calcium Chloride, and EGTA. A time-of-addition assay assessed the antiviral effect of Verapamil. Key findings Mice infected with RSV and treated with Verapamil exhibited a significant decrease in weight loss, an increase in survival rates, and reductions in viral titers, RSV F protein expression, inflammatory responses, and lung tissue injury. Verapamil reduced intracellular calcium levels, which correlated with reduced viral titers. The addition of calcium chloride reversed the anti-viral effects mediated by Verapamil, while EGTA potentiated them. The antiviral activity of Verapamil was observed during the early phase of RSV infection, likely by blocking Ca 2+ channels and inhibiting virus replication. Significance Verapamil effectively inhibits RSV infection by blocking calcium channels and reducing intracellular calcium levels, thereby impeding viral replication. Thus, Verapamil shows promise as a treatment for RSV.
研究领域:
药理学
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病毒学
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免疫学
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分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RENEWABLE ENERGY
·
2022
·
IF 8.634
Zhijin Zhang,Yingjie Du,Geling Kuang,Xuejian Shen,Xiaotong Jia,Ziyuan Wang,Yuxiao Feng,Shiru Jia,Fufeng Liu,Muhammad Bilal,Jiandong Cui
The production of biodiesel catalyzed by lipase has the advantages of simple process, low energy consumption, and low wastewater treatment requirements. However, low activity, poor stability, and difficulty in recycling still limit the application of lipase in production of biodiesel. Herein, a novel lipase hybrid biocatalyst with superior catalytic activity and stability (lipase from Aspergillus oryzae CJLU-3, AOCL@CaP in DES) was developed by dual activation of Ca 2+ and interfacial effect of deep-eutectic solvents (DES)/water two-phase system. AOCL@CaP in DES exhibited significantly enhanced enzymatic activity with a K cat /K m value of 692 s −1 mM −1 and excellent thermostability, tolerance to chemical denaturants, substrate selectivity, and reusability compared with free lipase. Recovery activity of the prepared hybrid biocatalyst in pure water system (AOCL@CaP) and AOCL@CaP in DES was 195% and 250% using p-NPL as substrate, respectively. AOCL@CaP in DES exhibited about 253% of the original activity after 100 days of storage, while free AOCL, AOCL@CaP almost completely lost activity. The FAME content in product biodiesel catalyzed from soybean oil by AOCL@CaP was only 60%, However, the FAME content catalyzed by AOCL@CaP in DES reached 87%, and could be maintained at 50% even after 10 cycles.
研究领域:
生物化学
·
催化工程
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 79
·75664-75668
·
IF 3.289
Zhenmin Xiong,Yushi Yang,Youfa Wang
LiGdF4 nanoparticles (NPs) with different Ca2+ contents were synthesized by a thermal decomposition method. The as-prepared NPs were able to emit green and strong red light when excited by a 980 nm laser through a two-photon process and they were characterized by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), and photoluminescence (PL) spectroscopy. Rietveld refinement was performed to explore the structure and phase composition of the product. It was found that Ca2+ ions were vital to the successful synthesis of LiGdF4 NPs and an appropriate Ca2+ content (ca. 19%) yielded the product with highest purity. The purity of the obtained product was highly correlated with the PL intensity and red/green light intensity ratio.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
STAR Protocols
·
2021
·
IF 0
Yunjing Wang,Qian Gong,Fan Huang,Linfang He,Yule Liu
Summary Wounding evokes transient increases in cytosolic calcium (Ca 2+ ) concentration. Visualizing real-time Ca 2+ flux provides new insights into Ca 2+ -signaling pathways. Here, we outline a protocol to detect insect feeding-induced Ca 2+ flux elevation in Nicotiana benthamiana leaves based on the GCaMP3 reporter system by Leica fluorescence stereo microscopes (LFSM). LFSM combines super-fast manual screening with high-end imaging capabilities. Through this protocol, we can clearly observe the calcium flow after aphid’s piercing-sucking. Additionally, we describe a protocol to quantify Ca 2+ level using LFSM. For complete details on the use and execution of this protocol, please refer to Wang et al. (2021) .
研究领域:
植物生物学
·
分子生物学
·
昆虫学
✓ 已验证
DOI
PubMed
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2016
·Vol. 23
·期 12
·11611-11619
·
IF 2.76
Miao Lingzhan,Wang Chao,Hou Jun,Wang Peifang,Ao Yanhui,Li Yi,Lv Bowen,Yang Yangyang,You Guoxiang,Xu Yi
The stability of CuO nanoparticles (NPs) is expected to play a key role in the environmental risk assessment of nanotoxicity in aquatic systems. In this study, the effect of alginate (model polysaccharides) on the stability of CuO NPs in various environmentally relevant ionic strength conditions was investigated by using time-resolved dynamic light scattering. Significant aggregation of CuO NPs was observed in the presence of both monovalent and divalent cations. The critical coagulation concentrations (CCC) were 54.5 and 2.9 mM for NaNO 3 and Ca(NO 3 ) 2 , respectively. The presence of alginate slowed nano-CuO aggregation rates over the entire NaNO 3 concentration range due to the combined electrostatic and steric effect. High concentrations of Ca 2+ (>6 mM) resulted in stronger adsorption of alginate onto CuO NPs; however, enhanced aggregation of CuO NPs occurred simultaneously under the same conditions. Spectroscopic analysis revealed that the bridging interaction of alginate with Ca 2+ might be an important mechanism for the enhanced aggregation. Furthermore, significant coagulation of the alginate molecules was observed in solutions of high Ca 2+ concentrations, indicating a hetero-aggregation mechanism between the alginate-covered CuO NPs and the unabsorbed alginate. These results suggested a different aggregation mechanism of NPs might co-exist in aqueous systems enriched with natural organic matter, which should be taken into consideration in future studies.
Hetero-aggregation mechanism of CuO nanoparticles and alginate under high concentration of Ca 2+
研究领域:
环境科学
·
纳米毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
DALTON TRANSACTIONS
·
2022
·Vol. 51
·期 8
·3159-3169
·
IF 4.569
Qinghong Meng,Guoying Zhao,Qi Zhu,Xudong Sun,Ji-Guang Li
Doping Gd2LuAl5O12:Ce with a Ca2+/Si4+ pair produced a series of Gd1.97−xLuCaxAl5−xSixO12:0.03Ce (x = 0.0–1.2) garnet new phosphors, and remarkable regulation of the crystal structure and Ce3+ luminescence was achieved. Rietveld refinement and spectral analysis revealed that greater incorporation of Ca2+/Si4+ led to a higher lattice rigidity by cell contraction, a narrower bandgap, a longer average bond length/less distortion of the [CeO8] dodecahedron and decreased centroid shift/crystal field splitting of the Ce3+ 5d energy level. A blue-shifted 4f–5d1 transition, a narrower emission band, improved thermal stability of luminescence and a shorter fluorescence lifetime were observed with increasing Ca2+/Si4+ content. Applying the yellowish-green-emitting Gd0.77LuCa1.2Al3.8Si1.2O12:0.03Ce optimal phosphor (x = 1.2), together with a commercial CaAlSiN3:Eu red phosphor, in 450 nm-excited LED lighting produced a low CCT of ∼3625 K and a high CRI/R9 of ∼95.2/94.8, indicating that the phosphor has application potential in high-performance w-WLED.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Kaiming Zhu,Cunbao Gu,Xuanpu Zhou,Haoyang Li,Zichao Zhang,Haoran Cao,Kexin Liu,Jiamu Cui,Yihe Huang,Xiaochuang Ye,Qida Tian,Yirui Yang,Jianmin Song
AlN based phosphors have a wide range of applications and the green and blue emission of AlN:Eu 2+ phosphors have been reported a lot, while we found yellow emission in this phosphor. In this work, a series of different concentrations of Ca 2+ -doped AlN:Eu 2+ phosphors have been successfully prepared by a freeze drying assisted combustion synthesis, of which the crystal structure, morphology, photoluminescence properties and luminescence mechanism were studied in detail. The results show that Ca 2+ ions have been successfully doped into the AlN:Eu 2+ lattice and cause the lattice distortion, which has a great influence on the luminescent properties of the phosphors. Under the 365 nm excitation, the phosphors present a single emission peak, which is ascribed to the 4f 6 5d-4f 7 transitions of Eu 2+ ions. Furthermore, by increasing the doping amount of Ca 2+ ions (0.1, 0.5, 1 and 3 at %), the emission wavelength can be tuned from 516 to 535 nm, corresponding to the emission color from green to yellow, which is owing to the enhancement of the crystal field intensity around Eu 2+ ions through the interaction between Ca 2+ and Eu 2+ ions. Tuning of the emission wavelength for AlN:Eu 2+ phosphors is of great importance in expanding the applications of AlN:Eu 2+ phosphors in various luminescent fields.
研究领域:
材料科学
·
发光材料
·
磷光体制备
·
光学性能
✓ 已验证
产品关联
DOI
高影响因子
Advanced Energy Materials
·
2019
·Vol. 9
·期 28
·1901205
·
IF 24.884
Yao Lu,Jose A. Alonso,Qiang Yi,Liang Lu,Zhong Lin Wang,Chunwen Sun
Solid-state sodium batteries (SSSBs) are promising electrochemical energy storage devices due to their high energy density, high safety, and abundant resource of sodium. However, low conductivity of solid electrolyte as well as high interfacial resistance between electrolyte and electrodes are two main challenges for practical application. To address these issues, pure phase Na 3 Zr 2 Si 2 PO 12 (NZSP) materials with Ca 2+ substitution for Zr 4+ are synthesized by a sol-gel method. It shows a high ionic conductivity of more than 10 −3 S cm −1 at 25 °C. Moreover, a robust SSSB is developed by integrating sodium metal anodes into NZSP-type monolithic architecture, forming a 3D electronic and ionic conducting network. The interfacial resistance is remarkably reduced and the monolithic symmetric cell displays stable sodium platting/striping cycles with low polarization for over 600 h. Furthermore, by combining sodium metal anode with Na 3 V 2 (PO 4 ) 3 cathode, an SSSB is demonstrated with high rate capability and excellent cyclability. After 450 cycles, the capacity of the cell is still kept at 94.9 mAh g −1 at 1 C. This unique design of monolithic electrolyte architecture provides a promising strategy toward realizing high-performance SSSBs.
研究领域:
材料科学
·
电化学
·
储能
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）