| 1. |
- Zhang, Yinping, et al.
(författare)
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Ten cities cross-sectional questionnaire survey of children asthma and other allergies in China
- 2013
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Ingår i: Chinese Science Bulletin. - : Springer Science and Business Media LLC. - 1001-6538 .- 1861-9541. ; 58:34, s. 4182-4189
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Tidskriftsartikel (refereegranskat)abstract
- Asthma, rhinitis and eczema (allergic or non-allergic) have increased throughout the world during the last decades, especially among children. Changes in the indoor environment are suspected to be important causes. China has experienced a dramatic change in indoor environmental exposures during the past two decades. However, such changes and their associations with children's asthma and other health aspects have not been thoroughly studied. China, Children, Homes, Health (CCHH), Phase I, was a cross-sectional questionnaire survey of 48219 children 1-8 years old in 10 Chinese cities during 2010-2012. The questionnaire includes the International Study of Asthma and Allergies in Childhood (ISAAC) core health questions and additional questions regarding housing, life habits and outdoor environment. In health analyses, children aged 3-6 years old were included. The prevalences of doctor diagnosed asthma varied from 1.7% to 9.8% (mean 6.8%), a large increase from 0.91% in 1999 and 1.50% in 2000. The prevalence of wheeze, rhinitis and atopic eczema (last 12 months) varied from 13.9% to 23.7%, 24.0% to 50.8% and 4.8% to 15.8%, respectively. Taiyuan had the lowest prevalences of all illnesses and Shanghai the highest, except for wheezewhere the highest value was for Urumqi. We found (1) no obvious association between disease prevalences and ambient PM10 concentrations and (2) higher prevalences of disease in humid climates with hot summers and cold winters, but with no centrally heated buildings. Associations between the diseases and economic status as indexed by Gross Domestic Product (GDP) requires further study.
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| 2. |
- Karlsson, M., et al.
(författare)
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Wafer-scale epitaxial graphene on SiC for sensing applications
- 2015
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Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE - The International Society for Optics and Photonics. - 9781628418903
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Konferensbidrag (refereegranskat)abstract
- The epitaxial graphene-on-silicon carbide (SiC-G) has advantages of high quality and large area coverage owing to a natural interface between graphene and SiC substrate with dimension up to 100 mm. It enables cost effective and reliable solutions for bridging the graphene-based sensors/devices from lab to industrial applications and commercialization. In this work, the structural, optical and electrical properties of wafer-scale graphene grown on 2'™'™ 4H semi-insulating (SI) SiC utilizing sublimation process were systemically investigated with focus on evaluation of the graphene'™s uniformity across the wafer. As proof of concept, two types of glucose sensors based on SiC-G/Nafion/Glucose-oxidase (GOx) and SiC-G/Nafion/Chitosan/GOx were fabricated and their electrochemical properties were characterized by cyclic voltammetry (CV) measurements. In addition, a few similar glucose sensors based on graphene by chemical synthesis using modified Hummer'™s method were also fabricated for comparison.
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| 3. |
- Zhao, Wei, et al.
(författare)
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Evaluation of Zinc Oxide Nano-Microtetrapods for Biomolecule Sensing Applications
- 2015
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Ingår i: MICRO+NANO MATERIALS, DEVICES, AND SYSTEMS. - : SPIE - International Society for Optical Engineering. - 9781628418903
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Konferensbidrag (refereegranskat)abstract
- Zinc oxide tetrapods (ZnO-Ts) were synthesized by flame transport synthesis using Zn microparticles. This work herein reports a systematical study on the structural, optical and electrochemical properties of the ZnO-Ts. The morphology of the ZnO-Ts was confirmed by scanning electron microscopy (SEM) as joint structures of four nano-microstructured legs, of which the diameter of each leg is 0.7-2.2 mu m in average from the tip to the stem. The ZnO-Ts were dispersed in glucose solution to study the luminescence as well as photocatalytic activity in a mimicked biological environment. The photoluminescence (PL) intensity in the ultraviolet (UV) region decreased with linear dependence on the glucose concentration up to 4 mM. The ZnO-Ts were also attached with glucose oxidase (GOx) and over coated with a thin film of Nafion to form active layers on Si/SiO2/Au substrate for electrochemical glucose sensing. The attachment of GOx and the coating of Nafion onto ZnO-Ts were confirmed by Fourier transform infrared spectroscopy (FT-IR). Furthermore, the current response of the active layers based on ZnO-Ts was investigated by cyclic voltammetry (CV) in various glucose concentration conditions. Stable current response of glucose was detected with linear dependence on the glucose concentration up to 12 mM, which confirms the potential of ZnO-Ts for biomolecule sensing applications.
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| 4. |
- Fall, Andreas, et al.
(författare)
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Hybrid Materials of Nanocellulose and Graphene
- 2019
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Ingår i: <em>International Conference on Nanotechnology for Renewable Materials 2019</em>. - : TAPPI Press. ; , s. 1069-1080
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Konferensbidrag (refereegranskat)
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| 5. |
- Majee, Subimal, 1984-, et al.
(författare)
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Highly Conductive Films by Rapid Photonic Annealing of Inkjet Printable Starch–Graphene Ink
- 2021
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Ingår i: Advanced Materials Interfaces. - : John Wiley and Sons Inc. - 2196-7350. ; 9:5
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Tidskriftsartikel (refereegranskat)abstract
- A general formulation engineering method is adopted in this study to produce a highly concentrated (≈3 mg mL−1) inkjet printable starch–graphene ink in aqueous media. Photonic annealing of the starch–graphene ink is validated for rapid post-processing of printed films. The experimental results demonstrate the role of starch as dispersing agent for graphene in water and photonic pulse energy in enhancing the electrical properties of the printed graphene patterns, thus leading to an electrical conductivity of ≈2.4 × 104 S m−1. The curing mechanism is discussed based on systematic material studies. The eco-friendly and cost-efficient approach presented in this work is of technical potential for the scalable production and integration of conductive graphene inks for widespread applications in printed and flexible electronics.
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| 6. |
- Wei, Xin-Feng, et al.
(författare)
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Risk for the release of an enormous amount of nanoplastics and microplastics from partially biodegradable polymer blends
- 2022
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Ingår i: Green Chemistry. - : Royal Society of Chemistry (RSC). - 1463-9262 .- 1463-9270. ; 24:22, s. 8742-8750
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Tidskriftsartikel (refereegranskat)abstract
- Nanoplastics and microplastics (NMPs) in natural environments are an emerging global concern and understanding their formation processes from macro-plastic items during degradation/weathering is critical for predicting their quantities and impacts in different ecological systems. Here, we show the risk of enormous emissions of NMPs from polymer blends, a source that has not been specifically studied, by taking immiscible (most common case) partially biodegradable polymer blends as an example. The blends have the common “sea-island” morphology, where the minor non-biodegradable polymer phase (polyethylene and polypropylene) is dispersed as NMP particles in the major continuous biodegradable matrix (poly(ϵ-caprolactone)). The dispersed NMP particles with spherical and rod-like shapes are gradually liberated and released to the surrounding aquatic environment during the biodegradation of the matrix polymer. Strikingly, the number of released NMPs from the blend is very high. The blend film surface erosion process, induced by enzymatic hydrolysis of the matrix, involving fragmentation, hole formation, and hole wall detachment, was systematically investigated to reveal the NMP release process. Our findings present direct evidence and detailed insights into the high risk of emissions of NMPs from partially biodegradable immiscible polymer blends with a widespread “sea-island” morphology. Efforts from authorities, developers, manufacturers, and the public are needed to avoid the use of non-biodegradable polymers in blends with biodegradable polymers.
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| 7. |
- Zhao, Wei, et al.
(författare)
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Graphene and Flavin Mononucleotide Interaction in Aqueous Graphene Dispersions
- 2019
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Ingår i: The Journal of Physical Chemistry C. - : American Chemical Society. - 1932-7447 .- 1932-7455. ; 123:43, s. 26282-26288
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Tidskriftsartikel (refereegranskat)abstract
- A fundamental understanding of the interaction between graphene and a stabilizer is needed for the development of stable aqueous graphene dispersions. Here, we studied the interaction of graphene with the FMN in water. The UV-vis absorption spectra revealed blue shifts of the FMN absorption bands II (374 nm) and I (445 nm) in the presence of graphene. Furthermore, Fourier transform IR anal. showed that the graphene also upshifted the FMN vibration modes C10a=N1 and C4a=N5, which correspond to the FMN isoalloxazine binding sites N(1) and N(5), resp. In addition, thermogravimetric anal. showed that the thermal stability of graphene was enhanced by the adsorbed FMN, which supports the strong interaction. These results confirm that FMN adsorbs on the graphene surface in parallel conformation and hinders hydrogen bonding at the FMN isoalloxazine binding sites.
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| 8. |
- Zhao, Wei, et al.
(författare)
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Surfactant-Free Stabilization of Aqueous Graphene Dispersions Using Starch as a Dispersing Agent
- 2021
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Ingår i: ACS Omega. - : American Chemical Society. - 2470-1343. ; 6:18, s. 12050-12062
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Tidskriftsartikel (refereegranskat)abstract
- Attention to graphene dispersions in water with the aid of natural polymers is increasing with improved awareness of sustainability. However, the function of biopolymers that can act as dispersing agents in graphene dispersions is not well understood. In particular, the use of starch to disperse pristine graphene materials deserves further investigation. Here, we report the processing conditions of aqueous graphene dispersions using unmodified starch. We have found that the graphene content of the starch-graphene dispersion is dependent on the starch fraction. The starch-graphene sheets are few-layer graphene with a lateral size of 3.2 μm. Furthermore, topographical images of these starch-graphene sheets confirm the adsorption of starch nanoparticles with a height around 5 nm on the graphene surface. The adsorbed starch nanoparticles are ascribed to extend the storage time of the starch-graphene dispersion up to 1 month compared to spontaneous aggregation in a nonstabilized graphene dispersion without starch. Moreover, the ability to retain water by starch is reduced in the presence of graphene, likely due to environmental changes in the hydroxyl groups responsible for starch-water interactions. These findings demonstrate that starch can disperse graphene with a low oxygen content in water. The aqueous starch-graphene dispersion provides tremendous opportunities for environmental-friendly packaging applications. © 2021 American Chemical Society.
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| 9. |
- Zhao, Wei, et al.
(författare)
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Surfactant-free starch-graphene composite films as simultaneous oxygen and water vapour barriers
- 2022
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Ingår i: npj 2D Materials and Applications. - : Nature Research. - 2397-7132. ; 6:1
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Tidskriftsartikel (refereegranskat)abstract
- A single coating formulation for multifunctional composites, such as a gas barrier against both oxygen and water vapour, is the holy grail for the packaging industry. Since the last decade, graphene has been touted as the ideal barrier material in composites due to its morphology and impermeability to all gases. However, this prospect is limited by either poor dispersion of graphene or excess surfactants to aid the dispersion, both leading to shortcuts that allow gas permeation through the composite. Here, we demonstrate a combined gas barrier with starch-graphene composite films made from a single formulation of surfactant-free starch nanoparticle-stabilized graphene dispersion (2.97 mg mL−1). Hence, the incorporated graphene reduces the permeability of both the oxygen and the water vapour by over 70% under all the relative humidity conditions tested. Moreover, these films are foldable and electrically conductive (9.5 S m−1). Our surfactant-free approach of incorporating graphene into an industrially important biopolymer is highly relevant to the packaging industry, thus offering cost-effective and water-based solution depositions of multifunctional composite films for wide-ranging applications, such as gas barriers in food packaging. © 2022, The Author(s).
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