The Experts below are selected from a list of 54099 Experts worldwide ranked by ideXlab platform
Yongkuan Gong - One of the best experts on this subject based on the ideXlab platform.
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group reorientation and migration of amphiphilic Polymer bearing phosphorylcholine functionalities on surface of cellular membrane mimicking Coating
Journal of Biomedical Materials Research Part A, 2008Co-Authors: Shan Yang, Shiping Zhang, Francoise M Winnik, Fackson Mwale, Yongkuan GongAbstract:Amphiphilic Polymers bearing phosphorylcholine (PC) groups can form films of interfacial structure similar to that of the outer membrane of living cells. The films, as prepared, present PC groups to the external aqueous environment and exhibit good biocompatibility. However, under certain conditions, the surface structure can change irreversibly due to the reorientation and deep migration of the surface groups. X-ray photoelectron spectroscopy (XPS), dynamic contact angle measurements, and cell culture experiments were used to investigate the reorientation and migration of the surface groups of an amphiphilic PC-Polymer Coating. When the Polymer surface is immersed into or drawn out of water, significant reorientation and group migration occurs, as suggested by the large difference between the advancing and receding contact angles. Angle-resolved XPS measurements indicate that the hydrophobic groups move to the air/film interface while the hydrophilic groups migrate towards the bulk of the Polymer Coating. Long periods of aging may result in irreversible changes of the surface structure and decrease the biocompatibility of the materials. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
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group reorientation and migration of amphiphilic Polymer bearing phosphorylcholine functionalities on surface of cellular membrane mimicking Coating
Journal of Biomedical Materials Research Part A, 2008Co-Authors: Shan Yang, Shiping Zhang, Francoise M Winnik, Fackson Mwale, Yongkuan GongAbstract:Amphiphilic Polymers bearing phosphorylcholine (PC) groups can form films of interfacial structure similar to that of the outer membrane of living cells. The films, as prepared, present PC groups to the external aqueous environment and exhibit good biocompatibility. However, under certain conditions, the surface structure can change irreversibly due to the reorientation and deep migration of the surface groups. X-ray photoelectron spectroscopy (XPS), dynamic contact angle measurements, and cell culture experiments were used to investigate the reorientation and migration of the surface groups of an amphiphilic PC-Polymer Coating. When the Polymer surface is immersed into or drawn out of water, significant reorientation and group migration occurs, as suggested by the large difference between the advancing and receding contact angles. Angle-resolved XPS measurements indicate that the hydrophobic groups move to the air/film interface while the hydrophilic groups migrate towards the bulk of the Polymer Coating. Long periods of aging may result in irreversible changes of the surface structure and decrease the biocompatibility of the materials.
Shan Yang - One of the best experts on this subject based on the ideXlab platform.
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group reorientation and migration of amphiphilic Polymer bearing phosphorylcholine functionalities on surface of cellular membrane mimicking Coating
Journal of Biomedical Materials Research Part A, 2008Co-Authors: Shan Yang, Shiping Zhang, Francoise M Winnik, Fackson Mwale, Yongkuan GongAbstract:Amphiphilic Polymers bearing phosphorylcholine (PC) groups can form films of interfacial structure similar to that of the outer membrane of living cells. The films, as prepared, present PC groups to the external aqueous environment and exhibit good biocompatibility. However, under certain conditions, the surface structure can change irreversibly due to the reorientation and deep migration of the surface groups. X-ray photoelectron spectroscopy (XPS), dynamic contact angle measurements, and cell culture experiments were used to investigate the reorientation and migration of the surface groups of an amphiphilic PC-Polymer Coating. When the Polymer surface is immersed into or drawn out of water, significant reorientation and group migration occurs, as suggested by the large difference between the advancing and receding contact angles. Angle-resolved XPS measurements indicate that the hydrophobic groups move to the air/film interface while the hydrophilic groups migrate towards the bulk of the Polymer Coating. Long periods of aging may result in irreversible changes of the surface structure and decrease the biocompatibility of the materials. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
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group reorientation and migration of amphiphilic Polymer bearing phosphorylcholine functionalities on surface of cellular membrane mimicking Coating
Journal of Biomedical Materials Research Part A, 2008Co-Authors: Shan Yang, Shiping Zhang, Francoise M Winnik, Fackson Mwale, Yongkuan GongAbstract:Amphiphilic Polymers bearing phosphorylcholine (PC) groups can form films of interfacial structure similar to that of the outer membrane of living cells. The films, as prepared, present PC groups to the external aqueous environment and exhibit good biocompatibility. However, under certain conditions, the surface structure can change irreversibly due to the reorientation and deep migration of the surface groups. X-ray photoelectron spectroscopy (XPS), dynamic contact angle measurements, and cell culture experiments were used to investigate the reorientation and migration of the surface groups of an amphiphilic PC-Polymer Coating. When the Polymer surface is immersed into or drawn out of water, significant reorientation and group migration occurs, as suggested by the large difference between the advancing and receding contact angles. Angle-resolved XPS measurements indicate that the hydrophobic groups move to the air/film interface while the hydrophilic groups migrate towards the bulk of the Polymer Coating. Long periods of aging may result in irreversible changes of the surface structure and decrease the biocompatibility of the materials.
Michael K. Faulde - One of the best experts on this subject based on the ideXlab platform.
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synergistic insecticidal and repellent effects of combined pyrethroid and repellent impregnated bed nets using a novel long lasting Polymer Coating multi layer technique
Parasitology Research, 2012Co-Authors: Michael K. Faulde, Oliver NehringAbstract:New and improved strategies for malaria control and prevention are urgently needed. As a contribution to an optimized personal protection strategy, a novel long-lasting insecticide and repellent-treated net (LLIRN) has been designed by binding combinations of permethrin plus N,N-diethyl-m-toluamide (DEET), or insect repellent 3535 (IR3535), and etofenprox plus DEET, onto fibres of bed net fabric employing a new multi-layer Polymer-Coating technique. Protective repellent efficacy, toxicological effectiveness and residual activity of 12 LLIRN types have been evaluated by laboratory testing against adult Aedes aegypti. The novel multi-layer LLIRN design allowed simultaneous embedding at concentrations up to 5,930 mg/m2 for DEET, 3,408 mg/m2 for IR3535, 2,296 mg/m2 for permethrin and 2,349 mg/m2 for etofenprox, respectively. IR3535 layers prevented co-binding of additional pyrethroid-containing Polymer layers, thus making pyrethroids plus DEET LLIRNs an ideal combination. All LLIRNs revealed synergistic insecticidal effects which, when measured against concentration controls of the isolated compounds, were significant in all LLIRN types designed. DEET in DEET plus permethrin LLIRNs significantly (p < 0.0001) reduced the concentration-dependent permethrin 100 % knockdown (KD) time from 55 to 75 %, the corresponding 100 % kill time (p < 0.0001) from 55 to 64 %. DEET in DEET plus etofenprox LLIRNs reduced the dose-specific 100 % knockdown (KD) time of etofenprox from 42 to 50 % (p = 0.004), the 100 % kill time from 25 to 38 % (p < 0.0001). Permethrin or etofenprox did not influence spatial repellency of DEET or IR3535 on LLIRNs. Vice versa, DEET and IR3535 increased spatial and excitatory repellency and reduced landing and probing frequency on LLIRNs resulting in strongly enhanced biting protection, even at low concentrations. One hundred percent biting and probing protection of stored LLIRNs was preserved for 83 weeks with the 5,930 mg/m2 DEET and 2,139 mg/m2 etofenprox LLIRN, for 72 weeks with the 5,002 mg/m2 DEET and 2,349 mg/m2 etofenprox LLIRN, for 63 weeks with the 3,590 mg/m2 DEET and 1,208 mg/m2 permethrin LLRN, and for 61 weeks with the 4,711 mg/m2 DEET and 702 mg/m2 etofenprox LLIRN. Because 100 % bite protection with up to 75 % quicker contact toxicity of pyrethroids were documented, synergistic toxicological and repellent effects of multi-layer Polymer-Coating LLIRNs may overcome LLIN-triggered selection pressure for development of new kdr- and metabolic pyrethroid resistances while simultaneously increasing protective efficacy also against kdr- and metabolic pyrethroid-resistant mosquitoes substantially due to the repellent-induced effects of LLIRNs thus indicating that this approach is a promising new candidate for future bed net, curtain, and window screen impregnation aiming at optimized prevention from mosquito-borne diseases.
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Insecticidal, acaricidal and repellent effects of DEET- and IR3535-impregnated bed nets using a novel long-lasting Polymer-Coating technique
Parasitology Research, 2010Co-Authors: Michael K. Faulde, Gunther Albiez, Oliver NehringAbstract:A novel long-lasting repellent-treated net (LLRTN) has been designed by binding the skin repellents N , N -diethyl- m -toluamide (DEET), or IR3535, onto the fibres of bed net fabric using a new Polymer-Coating technique. The repellent toxicological effectiveness and residual activity of a factory-based repellent-impregnated fabric has been evaluated by laboratory testing against adult Aedes aegypti mosquitoes and nymphal Ixodes ricinus ticks. By using this repellent-embedding impregnation technique, concentrations exceeding 10 g/m^2 could be achieved with one single Polymer layer. Both DEET- and IR3535-impregnated fabrics revealed a dose-dependent insecticidal as well as acaricidal activity. One hundred percent knockdown times of DEET-treated bed nets ranged from 187.5 ± 31.8 to 27.5 ± 3.5 min against A. aegypti , and between 214 ± 47 and 22.6 ± 5 min against nymphal I. ricinus , linked to a DEET concentration of 1.08 and 10.58 g/m^2, respectively. With IR3535, A. aegypti produced dose-dependent 100% knockdown times varying from 87.5 ± 10.6 to 57.5 ± 3.5 min and between 131.4 ± 6.5 and 33.8 ± 5 min against nymphal I. ricinus , respectively, linked to concentrations between 1.59 and 10.02 g/m^2. One hundred percent repellency measured by complete landing and biting protection of impregnated fabric by using the arm-in-cage test could be achieved at DEET concentrations exceeding 3.7 to 3.9 g/m^2, and for IR3535 concentrations over 10 g/m^2. One hundred percent landing and biting protection could be preserved with DEET-treated fabrics for 29 weeks at an initial concentration of 4.66 g/m^2, 54 weeks at 8.8 g/m^2, 58 weeks at 9.96 g/m^2 and 61 weeks at 10.48 g/m^2 for DEET, and 23 weeks for IR3535-treated fabric at a concentration of 10.02 g/m^2. Unlike repellent-treated fabric, a brand of a commercially available long-lasting insecticide-treated net tested containing 500 mg permethrin/m^2 did not protect from mosquito bites. First results on bioactivity and long-lasting efficacy show that the new LLRTN technique is highly promising as a potential candidate for future malaria control strategies, especially in areas where pyrethroid resistance occurs.
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a new clothing impregnation method for personal protection against ticks and biting insects
International Journal of Medical Microbiology, 2006Co-Authors: Michael K. Faulde, Waltraud M UedelhovenAbstract:The efficacy and residual activity of a factory-based, permethrin-impregnated military battle dress uniform (BDU) using a new Polymer-Coating technique has been evaluated by laboratory and field testing during deployment to Afghanistan and compared with two commercially available, widely used dipping methods. Residual permethrin concentrations and remaining contact toxicities on treated fabrics before laundering, after up to 100 launderings as well as after being worn-out during deployment were tested against Aedes aegypti (L.) and Ixodes ricinus (L.). The residual amount of permethrin was considerably higher with the Polymer-Coating technique with 280mg/m(2) remaining after 100 launderings. Polymer-coated BDUs collected for disposal after being worn-out during military deployment showed equivalent or better residual knockdown efficacy against test arthropods when compared with the results obtained with the US Army IDA (Illinois Department of Agriculture)-Kit after 50 launderings, which represent the recommended baseline for re-impregantion or disposal of the impregnated fabric. BDUs impregnated by the Polymer-Coating method were found to be effective throughout the lifetime of the uniform, ensuring protection of soldiers in the field from arthropod vectors, while simultaneously decreasing logistical constraints and occupational health threats.
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contact toxicity and residual activity of different permethrin based fabric impregnation methods for aedes aegypti diptera culicidae ixodes ricinus acari ixodidae and lepisma saccharina thysanura lepismatidae
Journal of Medical Entomology, 2003Co-Authors: Michael K. Faulde, Waltraud M Uedelhoven, Richard G RobbinsAbstract:Abstract The effectiveness and residual activities of permethrin-impregnated military battle dress uniforms were evaluated by comparing a new company-manufactured ready-to-use Polymer-Coating method with two “dipping methods” that are currently used to treat uniforms. Residual permethrin amounts and remaining contact toxicities on treated fabrics before and after up to 100 launderings were tested against Aedes aegypti (L.), Ixodes ricinus (L.), and Lepisma saccharina (L.). The residual amount of permethrin was considerably higher with the Polymer-Coating method: 280 mg a.i./m2 after 100 launderings, compared with 16 and 11 mg a.i./m2, respectively, obtained when using the two dipping methods. Hard ticks were most susceptible to the new Polymer-Coating method, resulting in prelaundering 100% knockdown times of 7.0 ± 0.9 min, whereas equivalent times for the dipping methods were 7.9 ± 0.35 min and 8.0 ± 0.54 min, respectively. After 100 launderings, 100% knockdown of I. ricinus nymphs was reached at 15.2 ± ...
Oliver Nehring - One of the best experts on this subject based on the ideXlab platform.
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synergistic insecticidal and repellent effects of combined pyrethroid and repellent impregnated bed nets using a novel long lasting Polymer Coating multi layer technique
Parasitology Research, 2012Co-Authors: Michael K. Faulde, Oliver NehringAbstract:New and improved strategies for malaria control and prevention are urgently needed. As a contribution to an optimized personal protection strategy, a novel long-lasting insecticide and repellent-treated net (LLIRN) has been designed by binding combinations of permethrin plus N,N-diethyl-m-toluamide (DEET), or insect repellent 3535 (IR3535), and etofenprox plus DEET, onto fibres of bed net fabric employing a new multi-layer Polymer-Coating technique. Protective repellent efficacy, toxicological effectiveness and residual activity of 12 LLIRN types have been evaluated by laboratory testing against adult Aedes aegypti. The novel multi-layer LLIRN design allowed simultaneous embedding at concentrations up to 5,930 mg/m2 for DEET, 3,408 mg/m2 for IR3535, 2,296 mg/m2 for permethrin and 2,349 mg/m2 for etofenprox, respectively. IR3535 layers prevented co-binding of additional pyrethroid-containing Polymer layers, thus making pyrethroids plus DEET LLIRNs an ideal combination. All LLIRNs revealed synergistic insecticidal effects which, when measured against concentration controls of the isolated compounds, were significant in all LLIRN types designed. DEET in DEET plus permethrin LLIRNs significantly (p < 0.0001) reduced the concentration-dependent permethrin 100 % knockdown (KD) time from 55 to 75 %, the corresponding 100 % kill time (p < 0.0001) from 55 to 64 %. DEET in DEET plus etofenprox LLIRNs reduced the dose-specific 100 % knockdown (KD) time of etofenprox from 42 to 50 % (p = 0.004), the 100 % kill time from 25 to 38 % (p < 0.0001). Permethrin or etofenprox did not influence spatial repellency of DEET or IR3535 on LLIRNs. Vice versa, DEET and IR3535 increased spatial and excitatory repellency and reduced landing and probing frequency on LLIRNs resulting in strongly enhanced biting protection, even at low concentrations. One hundred percent biting and probing protection of stored LLIRNs was preserved for 83 weeks with the 5,930 mg/m2 DEET and 2,139 mg/m2 etofenprox LLIRN, for 72 weeks with the 5,002 mg/m2 DEET and 2,349 mg/m2 etofenprox LLIRN, for 63 weeks with the 3,590 mg/m2 DEET and 1,208 mg/m2 permethrin LLRN, and for 61 weeks with the 4,711 mg/m2 DEET and 702 mg/m2 etofenprox LLIRN. Because 100 % bite protection with up to 75 % quicker contact toxicity of pyrethroids were documented, synergistic toxicological and repellent effects of multi-layer Polymer-Coating LLIRNs may overcome LLIN-triggered selection pressure for development of new kdr- and metabolic pyrethroid resistances while simultaneously increasing protective efficacy also against kdr- and metabolic pyrethroid-resistant mosquitoes substantially due to the repellent-induced effects of LLIRNs thus indicating that this approach is a promising new candidate for future bed net, curtain, and window screen impregnation aiming at optimized prevention from mosquito-borne diseases.
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Insecticidal, acaricidal and repellent effects of DEET- and IR3535-impregnated bed nets using a novel long-lasting Polymer-Coating technique
Parasitology Research, 2010Co-Authors: Michael K. Faulde, Gunther Albiez, Oliver NehringAbstract:A novel long-lasting repellent-treated net (LLRTN) has been designed by binding the skin repellents N , N -diethyl- m -toluamide (DEET), or IR3535, onto the fibres of bed net fabric using a new Polymer-Coating technique. The repellent toxicological effectiveness and residual activity of a factory-based repellent-impregnated fabric has been evaluated by laboratory testing against adult Aedes aegypti mosquitoes and nymphal Ixodes ricinus ticks. By using this repellent-embedding impregnation technique, concentrations exceeding 10 g/m^2 could be achieved with one single Polymer layer. Both DEET- and IR3535-impregnated fabrics revealed a dose-dependent insecticidal as well as acaricidal activity. One hundred percent knockdown times of DEET-treated bed nets ranged from 187.5 ± 31.8 to 27.5 ± 3.5 min against A. aegypti , and between 214 ± 47 and 22.6 ± 5 min against nymphal I. ricinus , linked to a DEET concentration of 1.08 and 10.58 g/m^2, respectively. With IR3535, A. aegypti produced dose-dependent 100% knockdown times varying from 87.5 ± 10.6 to 57.5 ± 3.5 min and between 131.4 ± 6.5 and 33.8 ± 5 min against nymphal I. ricinus , respectively, linked to concentrations between 1.59 and 10.02 g/m^2. One hundred percent repellency measured by complete landing and biting protection of impregnated fabric by using the arm-in-cage test could be achieved at DEET concentrations exceeding 3.7 to 3.9 g/m^2, and for IR3535 concentrations over 10 g/m^2. One hundred percent landing and biting protection could be preserved with DEET-treated fabrics for 29 weeks at an initial concentration of 4.66 g/m^2, 54 weeks at 8.8 g/m^2, 58 weeks at 9.96 g/m^2 and 61 weeks at 10.48 g/m^2 for DEET, and 23 weeks for IR3535-treated fabric at a concentration of 10.02 g/m^2. Unlike repellent-treated fabric, a brand of a commercially available long-lasting insecticide-treated net tested containing 500 mg permethrin/m^2 did not protect from mosquito bites. First results on bioactivity and long-lasting efficacy show that the new LLRTN technique is highly promising as a potential candidate for future malaria control strategies, especially in areas where pyrethroid resistance occurs.
Fackson Mwale - One of the best experts on this subject based on the ideXlab platform.
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group reorientation and migration of amphiphilic Polymer bearing phosphorylcholine functionalities on surface of cellular membrane mimicking Coating
Journal of Biomedical Materials Research Part A, 2008Co-Authors: Shan Yang, Shiping Zhang, Francoise M Winnik, Fackson Mwale, Yongkuan GongAbstract:Amphiphilic Polymers bearing phosphorylcholine (PC) groups can form films of interfacial structure similar to that of the outer membrane of living cells. The films, as prepared, present PC groups to the external aqueous environment and exhibit good biocompatibility. However, under certain conditions, the surface structure can change irreversibly due to the reorientation and deep migration of the surface groups. X-ray photoelectron spectroscopy (XPS), dynamic contact angle measurements, and cell culture experiments were used to investigate the reorientation and migration of the surface groups of an amphiphilic PC-Polymer Coating. When the Polymer surface is immersed into or drawn out of water, significant reorientation and group migration occurs, as suggested by the large difference between the advancing and receding contact angles. Angle-resolved XPS measurements indicate that the hydrophobic groups move to the air/film interface while the hydrophilic groups migrate towards the bulk of the Polymer Coating. Long periods of aging may result in irreversible changes of the surface structure and decrease the biocompatibility of the materials. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2008
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group reorientation and migration of amphiphilic Polymer bearing phosphorylcholine functionalities on surface of cellular membrane mimicking Coating
Journal of Biomedical Materials Research Part A, 2008Co-Authors: Shan Yang, Shiping Zhang, Francoise M Winnik, Fackson Mwale, Yongkuan GongAbstract:Amphiphilic Polymers bearing phosphorylcholine (PC) groups can form films of interfacial structure similar to that of the outer membrane of living cells. The films, as prepared, present PC groups to the external aqueous environment and exhibit good biocompatibility. However, under certain conditions, the surface structure can change irreversibly due to the reorientation and deep migration of the surface groups. X-ray photoelectron spectroscopy (XPS), dynamic contact angle measurements, and cell culture experiments were used to investigate the reorientation and migration of the surface groups of an amphiphilic PC-Polymer Coating. When the Polymer surface is immersed into or drawn out of water, significant reorientation and group migration occurs, as suggested by the large difference between the advancing and receding contact angles. Angle-resolved XPS measurements indicate that the hydrophobic groups move to the air/film interface while the hydrophilic groups migrate towards the bulk of the Polymer Coating. Long periods of aging may result in irreversible changes of the surface structure and decrease the biocompatibility of the materials.