The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Tahsin J Chow - One of the best experts on this subject based on the ideXlab platform.
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white light emitting devices based on star shape polymers with a Bisindolylmaleimide core
Macromolecules, 2010Co-Authors: Zhenghuan Lin, Yanduo Lin, Poting Chow, Chiahsing Sun, Tahsin J ChowAbstract:A new type of star-shape polymers employing Bisindolylmaleimide dye (2a−c) as the core and poly(2,7-fluorene) (PF) and/or poly(2,7-carbazole) (PC) as the arms were synthesized. These materials exhibited dual emissions consisting of an intensive blue luminescence from PF or PC and an orange emission from maleimide a result of partial energy transfer between the two. Highly efficient white light emitting devices were fabricated using a single emitting film made by spin-coating method. The electroluminescence (EL) properties of the devices were investigated from several directions, such as the loading amount of maleimide core, the concentration dependent spectral changes, the difference in the composition of arms, and the substituent effect in the indole segment, etc. A typical device based on the star-shape polymer MF001 containing 0.01 mol % of core exhibited a maximal luminous efficiency of 7.2 cd/A and external quantum efficiency of 3.2%. The device based on MMF001 with a methyl substituent on the indole...
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white light emitting devices with a single emitting layer based on Bisindolylmaleimide fluorophores
Journal of Materials Chemistry, 2009Co-Authors: Zhenghuan Lin, Yuhsheng Wen, Tahsin J ChowAbstract:A series of Bisindolylmaleimide dyes (1–3) were synthesized and they exhibited intensive orange to red color luminance deriving from charge transfer transitions. Highly efficient light-emitting devices were fabricated using these materials as emitters by doping 1% in a tris(8-hydroxyquinolinato)aluminium (Alq3) host, which performed in a quantum efficiency of ∼4% with a maximal intensity >40 000 cd/m2. Broad band white emission can be produced by combining their reddish color with another blue emitter. While doped in 4,4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (NPB) in suitable concentrations, dual emission was obtained from a single layer. The device with configuration ITO/PEDOT:PSS/dye 1 (1%):NPB/TPBI/LiF/Al yielded white light with maximum luminance efficiency of 6.6 cd/A, power efficiency of 6.4 lm/W and quantum efficiency of 2.6%, where PEDOT:PSS is poly(ethylenedioxythiophene):poly(styrenesulfonic acid), and TPBI is 2,2′,2″-(1,3,5-benzentriyl)tris(1-phenyl-1H-benzimidazole). This device can be turned on at a low voltage (<3 V) and emits a white color with CIE coordinate (0.32, 0.34), which stays invariant over a wide range of applied voltage.
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electroluminescence of Bisindolylmaleimide derivatives containing pentafluorophenyl substituents
Chemistry of Materials, 2006Co-Authors: Tzusan Yeh, Tahsin J Chow, Shengheng Tsai, Chingwen Chiu, Chengxue ZhaoAbstract:Bisindolylmaleimide derivatives containing nonfluorinated (1−3) and fluorinated (1F−4F) substituents were synthesized, and their performances on electroluminescence devices were compared. Two kinds of devices were fabricated, in which either AlQ3 (tris(8-hydroxyquinolinato)aluminum) or TPBI (2,2‘,2‘ ‘-(1,3,5-benzenetriyl)tris(1-phenyl-1H-benzimidazole)) was used as an electron-transporting (ET) medium. For nonfluorinated materials 1−3, a red emission was obtained in devices with an ITO/NPB/1−3/TPBI/Mg:Ag configuration (ITO and NPB denote indium−tin oxide and 4,4‘-bis[N-(1-naphthyl)-N-phenylamino]biphenyl, respectively), whereas dual emissions were observed in others using AlQ3 as the ET material. For fluorinated materials 1F−4F, dual emissions were observed in both kinds of devices. The second emission came from the ET layer, although a certain number of holes were annihilated with the electrons there. Compounds bearing pentafluorophenyl moieties exhibited a reduced potential energy for both the HOMO and ...
Zhenghuan Lin - One of the best experts on this subject based on the ideXlab platform.
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solvent dependent and highly selective anion sensing and molecular logic application of Bisindolylmaleimide derivatives
RSC Advances, 2017Co-Authors: Huimei Yao, Zhenghuan Lin, Jingwei Wang, Huan Chen, Xiaofei Mei, Qidan LingAbstract:A series of Bisindolylmaleimide dyes (IMs) with different N-substituents (IM-PFB, IM-TBA and IM-MB) and planarity (IMC-MB and IM-MB) were designed and synthesized to detect anions selectively and sensitively. The anion-sensing properties were investigated systematically by changing the N-substituents of maleimide, solvent type and molecular planarity. Results indicate that the anion recognition is significantly affected by the solvent type rather than the N-substituents. Different anion sensitivity in various solvents makes IMs selectively detect F− in ACN, H2PO4− in DCM and CN− in THF. Due to the fixed location of two NH groups, the dye IMC-MB with planar structure exhibits poor sensing selectivity in various solvents. The titration curves of anions show that the sensing mechanism of IMs in various solvents for anions is different. The further experimental and DFT/TDDFT calculation results demonstrate that the hydrogen bond interaction and deprotonation of one H atom take place in DCM and THF, respectively, and that the two interactions synchronously exist in ACN. Interestingly, the solvent-dependent anion recognition can make IM-PFB mimic the function of three kinds of decoders (1-to-2, 2-to-3 and 2-to-4), a 4-to-2 encoder and a 1 : 2 demultiplexer. It is really rare for one molecule to mimic so many logic operations.
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white light emitting devices based on star shape polymers with a Bisindolylmaleimide core
Macromolecules, 2010Co-Authors: Zhenghuan Lin, Yanduo Lin, Poting Chow, Chiahsing Sun, Tahsin J ChowAbstract:A new type of star-shape polymers employing Bisindolylmaleimide dye (2a−c) as the core and poly(2,7-fluorene) (PF) and/or poly(2,7-carbazole) (PC) as the arms were synthesized. These materials exhibited dual emissions consisting of an intensive blue luminescence from PF or PC and an orange emission from maleimide a result of partial energy transfer between the two. Highly efficient white light emitting devices were fabricated using a single emitting film made by spin-coating method. The electroluminescence (EL) properties of the devices were investigated from several directions, such as the loading amount of maleimide core, the concentration dependent spectral changes, the difference in the composition of arms, and the substituent effect in the indole segment, etc. A typical device based on the star-shape polymer MF001 containing 0.01 mol % of core exhibited a maximal luminous efficiency of 7.2 cd/A and external quantum efficiency of 3.2%. The device based on MMF001 with a methyl substituent on the indole...
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white light emitting devices with a single emitting layer based on Bisindolylmaleimide fluorophores
Journal of Materials Chemistry, 2009Co-Authors: Zhenghuan Lin, Yuhsheng Wen, Tahsin J ChowAbstract:A series of Bisindolylmaleimide dyes (1–3) were synthesized and they exhibited intensive orange to red color luminance deriving from charge transfer transitions. Highly efficient light-emitting devices were fabricated using these materials as emitters by doping 1% in a tris(8-hydroxyquinolinato)aluminium (Alq3) host, which performed in a quantum efficiency of ∼4% with a maximal intensity >40 000 cd/m2. Broad band white emission can be produced by combining their reddish color with another blue emitter. While doped in 4,4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (NPB) in suitable concentrations, dual emission was obtained from a single layer. The device with configuration ITO/PEDOT:PSS/dye 1 (1%):NPB/TPBI/LiF/Al yielded white light with maximum luminance efficiency of 6.6 cd/A, power efficiency of 6.4 lm/W and quantum efficiency of 2.6%, where PEDOT:PSS is poly(ethylenedioxythiophene):poly(styrenesulfonic acid), and TPBI is 2,2′,2″-(1,3,5-benzentriyl)tris(1-phenyl-1H-benzimidazole). This device can be turned on at a low voltage (<3 V) and emits a white color with CIE coordinate (0.32, 0.34), which stays invariant over a wide range of applied voltage.
Petr Kucera - One of the best experts on this subject based on the ideXlab platform.
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updates on the surface antigens of basophils cd16 on basophils of patients with respiratory or insect venom allergy and the rejection of cd203c and cd63 externalization decoupling by Bisindolylmaleimides
Clinical & Experimental Allergy, 2019Co-Authors: Petr Heneberg, Kamila Riegerova, Adela řihova, Daniela Simcikova, Petr KuceraAbstract:BACKGROUND: CD16 was previously suggested to be a new marker of basophils that is subject to downregulation by FceRI crosslinking. Certain compounds, including supraoptimal concentrations of the PKC inhibitors, Bisindolylmaleimides, decouple the release of granules containing CD203c, CD63 and histamine, and may thus help to identify the mechanisms related to the CD16 externalization. OBJECTIVE: We hypothesized that CD16 is differentially expressed on the surface of basophils in patients with birch pollen or insect venom allergy and is subject to a regulation in response to allergens. We also employed CD203c and CD63 externalization decoupling by Bisindolylmaleimides. METHODS: We performed a basophil activation test coupled with CD16 and histamine detection using cells isolated from patients with allergy to birch pollen or insect venom and negative controls. We employed two PKC inhibitors, Bisindolylmaleimide II and Ro 31-8220 at their supraoptimal concentrations and, after difficulties reproducing previously published data, we analyzed the fluorescence of these inhibitors alone. We identified the CD16 isoforms by sequencing nested RT-PCR amplicons from flow cytometry sorted basophils and by cleaving the CD16b GPI anchor using a phospholipase C. RESULTS: We provide the first evidence that CD16a is expressed as a surface antigen on a small subpopulation of human basophils in patients with respiratory and insect venom allergy, and this antigen shows increased surface expression following allergen challenge or FceRI crosslinking. We rejected the apparent decoupling of the surface expression of basophil activation markers following the administration of Bisindolylmaleimides. CONCLUSIONS & CLINICAL RELEVANCE: The inclusion of αCD16 in negative selection cocktails selects against a subset of basophils that are CD16+ or CD16dim . Using CD16dim basophils and unstained leucocytes, we show that previous studies with supraoptimal concentrations of Bisindolylmaleimides are likely flawed and are not associated with the differential expression of CD203c and CD63.
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updates on the surface antigens of basophils cd16 on basophils of patients with respiratory or insect venom allergy and the rejection of cd203c and cd63 externalization decoupling by Bisindolylmaleimides
Clinical & Experimental Allergy, 2019Co-Authors: Petr Heneberg, Kamila Riegerova, Adela řihova, Daniela Simcikova, Petr KuceraAbstract:BACKGROUND: CD16 was previously suggested to be a new marker of basophils that is subject to downregulation by FceRI crosslinking. Certain compounds, including supraoptimal concentrations of the PKC inhibitors, Bisindolylmaleimides, decouple the release of granules containing CD203c, CD63 and histamine, and may thus help to identify the mechanisms related to the CD16 externalization. OBJECTIVE: We hypothesized that CD16 is differentially expressed on the surface of basophils in patients with birch pollen or insect venom allergy and is subject to a regulation in response to allergens. We also employed CD203c and CD63 externalization decoupling by Bisindolylmaleimides. METHODS: We performed a basophil activation test coupled with CD16 and histamine detection using cells isolated from patients with allergy to birch pollen or insect venom and negative controls. We employed two PKC inhibitors, Bisindolylmaleimide II and Ro 31-8220 at their supraoptimal concentrations and, after difficulties reproducing previously published data, we analyzed the fluorescence of these inhibitors alone. We identified the CD16 isoforms by sequencing nested RT-PCR amplicons from flow cytometry sorted basophils and by cleaving the CD16b GPI anchor using a phospholipase C. RESULTS: We provide the first evidence that CD16a is expressed as a surface antigen on a small subpopulation of human basophils in patients with respiratory and insect venom allergy, and this antigen shows increased surface expression following allergen challenge or FceRI crosslinking. We rejected the apparent decoupling of the surface expression of basophil activation markers following the administration of Bisindolylmaleimides. CONCLUSIONS & CLINICAL RELEVANCE: The inclusion of αCD16 in negative selection cocktails selects against a subset of basophils that are CD16+ or CD16dim . Using CD16dim basophils and unstained leucocytes, we show that previous studies with supraoptimal concentrations of Bisindolylmaleimides are likely flawed and are not associated with the differential expression of CD203c and CD63.
James M Mullin - One of the best experts on this subject based on the ideXlab platform.
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the protein kinase c inhibitor Bisindolylmaleimide inhibits the tpa induced but not the tnf induced increase in llc pk1 transepithelial permeability
Biochemical and Biophysical Research Communications, 1995Co-Authors: C W Marano, K V Laughlin, L M Russo, James M MullinAbstract:Abstract The transepithelial paracellular permeability of an epithelium formed by LLC-PK 1 cells increases upon activation of protein kinase C (PKC) by the phorbol ester tumor promoter, TPA, or in response to the cytokine tumor necrosis factor-α (TNF). Until recently, however, we have not been able to inhibit the permeability effects of TPA or TNF using any of the currently available serine-threonine kinase inhibitors. In this study we report that treatment of epithelial cell sheets with the selective PKC inhibitor Bisindolylmaleimide, GF109203X, completely prevents the TPA-induced but not the TNF-α induced increase in tight junction permeability. While PKC-α still translocates from the cytosol to the membrane of TPA-stimulated epithelial cells overall PKC activity in the membrane fraction is markedly reduced in the presence of GFX.
Petr Heneberg - One of the best experts on this subject based on the ideXlab platform.
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updates on the surface antigens of basophils cd16 on basophils of patients with respiratory or insect venom allergy and the rejection of cd203c and cd63 externalization decoupling by Bisindolylmaleimides
Clinical & Experimental Allergy, 2019Co-Authors: Petr Heneberg, Kamila Riegerova, Adela řihova, Daniela Simcikova, Petr KuceraAbstract:BACKGROUND: CD16 was previously suggested to be a new marker of basophils that is subject to downregulation by FceRI crosslinking. Certain compounds, including supraoptimal concentrations of the PKC inhibitors, Bisindolylmaleimides, decouple the release of granules containing CD203c, CD63 and histamine, and may thus help to identify the mechanisms related to the CD16 externalization. OBJECTIVE: We hypothesized that CD16 is differentially expressed on the surface of basophils in patients with birch pollen or insect venom allergy and is subject to a regulation in response to allergens. We also employed CD203c and CD63 externalization decoupling by Bisindolylmaleimides. METHODS: We performed a basophil activation test coupled with CD16 and histamine detection using cells isolated from patients with allergy to birch pollen or insect venom and negative controls. We employed two PKC inhibitors, Bisindolylmaleimide II and Ro 31-8220 at their supraoptimal concentrations and, after difficulties reproducing previously published data, we analyzed the fluorescence of these inhibitors alone. We identified the CD16 isoforms by sequencing nested RT-PCR amplicons from flow cytometry sorted basophils and by cleaving the CD16b GPI anchor using a phospholipase C. RESULTS: We provide the first evidence that CD16a is expressed as a surface antigen on a small subpopulation of human basophils in patients with respiratory and insect venom allergy, and this antigen shows increased surface expression following allergen challenge or FceRI crosslinking. We rejected the apparent decoupling of the surface expression of basophil activation markers following the administration of Bisindolylmaleimides. CONCLUSIONS & CLINICAL RELEVANCE: The inclusion of αCD16 in negative selection cocktails selects against a subset of basophils that are CD16+ or CD16dim . Using CD16dim basophils and unstained leucocytes, we show that previous studies with supraoptimal concentrations of Bisindolylmaleimides are likely flawed and are not associated with the differential expression of CD203c and CD63.
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updates on the surface antigens of basophils cd16 on basophils of patients with respiratory or insect venom allergy and the rejection of cd203c and cd63 externalization decoupling by Bisindolylmaleimides
Clinical & Experimental Allergy, 2019Co-Authors: Petr Heneberg, Kamila Riegerova, Adela řihova, Daniela Simcikova, Petr KuceraAbstract:BACKGROUND: CD16 was previously suggested to be a new marker of basophils that is subject to downregulation by FceRI crosslinking. Certain compounds, including supraoptimal concentrations of the PKC inhibitors, Bisindolylmaleimides, decouple the release of granules containing CD203c, CD63 and histamine, and may thus help to identify the mechanisms related to the CD16 externalization. OBJECTIVE: We hypothesized that CD16 is differentially expressed on the surface of basophils in patients with birch pollen or insect venom allergy and is subject to a regulation in response to allergens. We also employed CD203c and CD63 externalization decoupling by Bisindolylmaleimides. METHODS: We performed a basophil activation test coupled with CD16 and histamine detection using cells isolated from patients with allergy to birch pollen or insect venom and negative controls. We employed two PKC inhibitors, Bisindolylmaleimide II and Ro 31-8220 at their supraoptimal concentrations and, after difficulties reproducing previously published data, we analyzed the fluorescence of these inhibitors alone. We identified the CD16 isoforms by sequencing nested RT-PCR amplicons from flow cytometry sorted basophils and by cleaving the CD16b GPI anchor using a phospholipase C. RESULTS: We provide the first evidence that CD16a is expressed as a surface antigen on a small subpopulation of human basophils in patients with respiratory and insect venom allergy, and this antigen shows increased surface expression following allergen challenge or FceRI crosslinking. We rejected the apparent decoupling of the surface expression of basophil activation markers following the administration of Bisindolylmaleimides. CONCLUSIONS & CLINICAL RELEVANCE: The inclusion of αCD16 in negative selection cocktails selects against a subset of basophils that are CD16+ or CD16dim . Using CD16dim basophils and unstained leucocytes, we show that previous studies with supraoptimal concentrations of Bisindolylmaleimides are likely flawed and are not associated with the differential expression of CD203c and CD63.