881 research outputs found
Colloidal thermoresponsive gel forming hybrids
No full textColloidal hybrids comprise organic and inorganic components and are attracting considerable attention in the literature. Recently, we reported hybrid anisotropic microsheets that formed thermoresponsive gels in polymer solutions [Liu et al., Langmuir, 25, 490, 2009]. Here, we investigate the composition and properties of these hybrid colloids themselves in detail for the first time. Three different cationic PNIPAm (N-isopropylacrylamide) graft copolymers and two inorganic nanoparticle types (laponite and Ludox silica) were used to prepare a range of hybrids. Anisotropic microsheets only formed when laponite particles were added to the copolymer implying directed self-assembly. Aqueous dispersions of the microsheets spontaneously formed gels at room temperature and these gels were thermoresponsive. They represent a new class of gel forming colloid and are termed thermoresponsive gel forming hybrids. The compositions of the hybrids were determined from thermogravimetric analysis and those that gave gel forming behaviour identified. Variable-temperature rheology experiments showed that the elasticity of the gels increased linearly with temperature. The reversibility of the thermally-triggered changes in gel elasticity was investigated. The concentration dependence of the rheology data was well described by elastic percolation scaling theory and the data could be collapsed onto a master curve. The concentration exponent for the elastic modulus was 2.5. The strong attractive interactions that exist between the dispersed gel forming hybrids was demonstrated by the formation of stable thermoresponsive hybrid hydrogels through casting of hybrid dispersions. © 2010 Elsevier Inc
Thermally Triggered Assembly of Cationic Graft Copolymers Containing 2-(2-Methoxyethoxy)ethyl Methacrylate Side Chains
No full textThermoresponsive copolymers continue to attract a great deal of interest in the literature. In particular, those based on ethylene oxide-containing methacrylates have excellent potential for biomaterial applications. Recently, some of us reported a study of thermoresponsive cationic graft copolymers containing poly(N-isopropylacrylamide), PNIPAm, (Liu et al., Langmuir, 24, 7099). Here, we report an improved version of this new family of copolymers. In the present study, we replaced the PNIPAm side chains with poly(2-(2- methyoxyethoxy)ethylmethacrylate), PMeO 2MA. These new, nonacrylamide containing, cationic graft copolymers were prepared using atom transfer radical polymerization (ATRP) and a macroinitiator. They contained poly(trimethylamonium)-aminoethyl methacrylate and PMeO 2MA, i.e., PTMA + x-g-(PMeO 2MA n) y. They were investigated using variable-temperature turbidity, photon correlation spectroscopy (PCS), electrophoretic mobility, and 1H NMR measurements. For one system, four critical temperatures were measured and used to propose a mechanism for the thermally triggered changes that occur in solution. All of the copolymers existed as unimolecular micelles at 20 °C. They underwent reversible aggregation with heating. The extent of aggregation was controlled by the length of the side chains. TEM showed evidence of micellar aggregates. The thermally responsive behaviors of our new copolymers are compared to those for the cationic PNIPAm graft copolymers reported by Liu et al. Our new cationic copolymers retained their positive charge at all temperatures studied, have high zeta potentials at 37 °C, and are good candidates for conferring thermoresponsiveness to negatively charged biomaterial surfaces. © 2011 American Chemical Society
sj-docx-1-jbc-10.1177_08839115241241294 – Supplemental material for Biocompatible sodium alginate–silk fibroin antibacterial microspheres from a microfluidic platform for infected wound repair
No full textSupplemental material, sj-docx-1-jbc-10.1177_08839115241241294 for Biocompatible sodium alginate–silk fibroin antibacterial microspheres from a microfluidic platform for infected wound repair by Jinglong Liu, Wei Zhou, Shuo Yang, Ruixue Chu, Yuqi Zhen, Rui Ding, Juan Xu, Zhiyong Qian and Ning Wen in Journal of Bioactive and Compatible Polymers</p
Supplement_Figure_1 - Analysis of mRNA Expression Patterns in Peripheral Blood Cells of 3 Patients With Cancer After the First Fraction of 2 Gy Irradiation: An Integrated Case Report and Systematic Review
No full textSupplement_Figure_1 for Analysis of mRNA Expression Patterns in Peripheral Blood Cells of 3 Patients With Cancer After the First Fraction of 2 Gy Irradiation: An Integrated Case Report and Systematic Review by Yue-Hua Nie, Xiao-Dan Liu, Ruixue Huang, Da-Fei Xie, Wen-Jun Yin, Hua Guan, Zi-Jian Yu, and Ping-Kun Zhou in Dose-Response</p
Supplement_Figure_3 - Analysis of mRNA Expression Patterns in Peripheral Blood Cells of 3 Patients With Cancer After the First Fraction of 2 Gy Irradiation: An Integrated Case Report and Systematic Review
No full textSupplement_Figure_3 for Analysis of mRNA Expression Patterns in Peripheral Blood Cells of 3 Patients With Cancer After the First Fraction of 2 Gy Irradiation: An Integrated Case Report and Systematic Review by Yue-Hua Nie, Xiao-Dan Liu, Ruixue Huang, Da-Fei Xie, Wen-Jun Yin, Hua Guan, Zi-Jian Yu, and Ping-Kun Zhou in Dose-Response</p
Supplement_Figure_2 - Analysis of mRNA Expression Patterns in Peripheral Blood Cells of 3 Patients With Cancer After the First Fraction of 2 Gy Irradiation: An Integrated Case Report and Systematic Review
No full textSupplement_Figure_2 for Analysis of mRNA Expression Patterns in Peripheral Blood Cells of 3 Patients With Cancer After the First Fraction of 2 Gy Irradiation: An Integrated Case Report and Systematic Review by Yue-Hua Nie, Xiao-Dan Liu, Ruixue Huang, Da-Fei Xie, Wen-Jun Yin, Hua Guan, Zi-Jian Yu, and Ping-Kun Zhou in Dose-Response</p
Supplementary-table1 - Analysis of mRNA Expression Patterns in Peripheral Blood Cells of 3 Patients With Cancer After the First Fraction of 2 Gy Irradiation: An Integrated Case Report and Systematic Review
No full textSupplementary-table1 for Analysis of mRNA Expression Patterns in Peripheral Blood Cells of 3 Patients With Cancer After the First Fraction of 2 Gy Irradiation: An Integrated Case Report and Systematic Review by Yue-Hua Nie, Xiao-Dan Liu, Ruixue Huang, Da-Fei Xie, Wen-Jun Yin, Hua Guan, Zi-Jian Yu, and Ping-Kun Zhou in Dose-Response</p
Changes in the VOC of Fruits at Different Refrigeration Stages of ‘Ruixue’ and the Participation of Carboxylesterase MdCXE20 in the Catabolism of Volatile Esters
No full textAroma is a crucial quality attribute of apple fruit, which significantly impacts its commercial value and consumer choice. Despite its importance the volatile aroma substances produced by the new variety ‘Ruixue’ after harvest remain unclear. In this study, we utilized headspace solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) to investigate the changes in volatile substances, fruit hardness, crispness, and related aroma synthase activity of commercially mature ‘Ruixue’ apples during cold storage. Our findings revealed a gradual decline in fruit firmness and brittleness of ‘Ruixue’ apples during cold storage, with hexyl acetate, hexyl caproate, and hexyl thiocyanate being the main hexyl esters detected. To gain a better understanding of the metabolic pathway of esters, we identified 42 MdCXE gene members that are associated with ester degradation. Through RT-qPCR analysis, we discovered that carboxylesterase MdCXE20 exhibited higher expression levels compared to other MdCXE genes during cold storage. To confirm the role of MdCXE20, we conducted a transient injection of apple fruits and observed that overexpression of MdCXE20 led to the degradation of esters such as hexyl hexanoate, butyl hexanoate, butyl 2-methylbutyrate, hexyl butyrate, and hexyl 2-methylbutyrate. The results of the study showed that the virus-induced gene silencing of MdCXE20 found the opposite results. Additionally, the esters of OE-MdCXE20 callus showed a lower content of ester VOC than the control callus, according to the homologous stable transformation of ‘Wanglin’ callus. Overall, these findings suggest that the MdCXE20 gene plays a crucial role in the decrease of esters in ‘Ruixue’ apples, which ultimately affects their flavor
Chaos synchronization of coupled neurons via H-infinity control with cooperative weights neural network
No full textImproved Device Performance of Polymer Solar Cells by Using a Thin Light-harvesting-Complex Modified ZnO Film as the Cathode Interlayer
No full textIn this study, a high-performance inverted polymer solar cell (PSC) has been fabricated by incorporating a zinc oxide (ZnO)/light-harvesting complex II (LHCII) stacked structure as the cathode interlayer. The LHCII not only smoothens the film surface of ZnO, improves the contact between ZnO and the photoactive layer, but also suppresses the charge carrier recombination at the interface, hence all the device parameters of PTB7-based solar cells are simultaneously improved, yielding higher power conversion efficiency (PCE) up to 9.01% compared with the control one (PCE 8.01%). And the thin LHCII modification layer also presents similar positive effects in the PTB7-Th:PC71BM system (PCE from 8.31% to 9.60%). These results put forward a facile approach to the interfacial modification in high-performance PSCs and provide new insight into developing and utilizing inexpensive and environmentally friendly materials from the fields of biological photosynthesis
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