Photochemical reactions of poly(3-butoxythiophene-2,5-diyl) with chloroform under irradiation with light were studied. The reactions were separately carried out under air, oxygen, and nitrogen. The obtained results sh...Photochemical reactions of poly(3-butoxythiophene-2,5-diyl) with chloroform under irradiation with light were studied. The reactions were separately carried out under air, oxygen, and nitrogen. The obtained results showed that this reaction belongs to the pseudo-first-order reaction with a rate constant kobs of 1.4×10?5 s?1 at room temperature. The presence or absence of air, oxygen, and nitrogen did not have obvious effects on the reaction rate under irradiation with light.展开更多
The present study was conducted with an aim to scale up the production of iturin A using soybean curd residue (okara). Iturin A was produced by indigenous bacterial strain Bacillus subtilis RB14-CS through glass colum...The present study was conducted with an aim to scale up the production of iturin A using soybean curd residue (okara). Iturin A was produced by indigenous bacterial strain Bacillus subtilis RB14-CS through glass column reactor (GCR) under solid state fermentation (SSF) was characterized. The enhanced iturin A production was observed with respect to enhanced substrate bed height when SSF was conducted in Erlenmeyer flask. To check the effect of substrate bed height on iturin A production under SSF of okara, GCR was introduced. Substrate bed height of 15 cm was suitable for iturin A production which was about 2700 mg/kg wet substrate. The observed iturin A production by the aerobic bacteria Bacillus subtilis in nearly anaerobic condition in such high substrate bed for SSF is a wonderful finding for development of SSF system in future.展开更多
Protonating the pyridine rings of poly(pyridine-2,5-diyl) with dodecybenzenesulfonic acid and camphorsulphonic acid produces polymer materials which can be dissolved in chloroform (in contrast to the unprotonated poly...Protonating the pyridine rings of poly(pyridine-2,5-diyl) with dodecybenzenesulfonic acid and camphorsulphonic acid produces polymer materials which can be dissolved in chloroform (in contrast to the unprotonated polymer, which can only be dissolved in strong acids such as formic acid) and allows mixing the protonated polymers with other chloroform soluble conju- gated polymers for use in electronic devices. The protonating behavior of poly(pyridine-2,5-diyl) with two kinds of surfactants is different in some levels. Dodecybenzenesulfonic acid has higher protonating ability than camphorsulphonic acid.展开更多
NiCl2(bpy) catalyzed polycondensation between p-dibromobenzene and m-dibromobenzene has been carried out under various conditions. The polycondensation endows the copolymer with an M-n of 2300 (by GPC, polystyrene sta...NiCl2(bpy) catalyzed polycondensation between p-dibromobenzene and m-dibromobenzene has been carried out under various conditions. The polycondensation endows the copolymer with an M-n of 2300 (by GPC, polystyrene standards) and good solubility in organic solvents. The fluorescence spectra of the copolymer measured with tetrahydrofuran solution shows an emission maximum (lambda(max)) at 372.8 nm, whereas for the film the maximum shifts to 436.6 nm.展开更多
Wettability transition is a significant responsive mechanism which is widely applied to construct smart materials and systems.The broad-spectrum responsiveness of the wettability transition makes it a promising way to...Wettability transition is a significant responsive mechanism which is widely applied to construct smart materials and systems.The broad-spectrum responsiveness of the wettability transition makes it a promising way to expand innovative applications.Here,we develop a track-guided self-transportation system mediated by sequential wettability transition accompanied with capillary transportation.Alkaline fuel is loaded into polydimethylsiloxane(PDMS)cuboid to trigger the wettability transition of distributed superhydrophobic tracks laid in shallow water.After the wettability transition,the induced capillary force can propel the repetitive track-to-track transportation of PDMS.Importantly,the spacing between adjacent tracks is rationally designed based on multiple factors including threshold of wettability transition,diffusion kinetics and capillary interaction.Furthermore,the track-guided transportation system is applied to realize directed self-assembly of multiple PDMS building blocks for designated configuration,which increases the complexity and intelligence of self-assembly systems.展开更多
1 Results Helix induction to polymer chains is an active area of research these days. In most cases,optically-active units are attached to the polymers to induce helical conformation. Scheme 1Since the properties of ...1 Results Helix induction to polymer chains is an active area of research these days. In most cases,optically-active units are attached to the polymers to induce helical conformation. Scheme 1Since the properties of σ-conjugated polymers like polysilanes are dependent on the conformation of the chain,it is particularly interesting to induce helix to oligo-and polysilanes. We have been working on the helix induction by host-guest complexation with sugar derivatives such as cyclodextrine and amylose.The l...展开更多
Thioredoxin is a small ubiquitous protein that is involved in the dithiol-disulfide exchange reaction, byway of two cysteine residues located on the molecule surface. In order to elucidate the role of thioredoxin in C...Thioredoxin is a small ubiquitous protein that is involved in the dithiol-disulfide exchange reaction, byway of two cysteine residues located on the molecule surface. In order to elucidate the role of thioredoxin in Chlorobaculum tepidurn, an anaerobic green sulfur bacterium that uses various inorganic sulfur compounds and H2S as electron donors under strict anaerobic conditions for growth, we applied the thioredoxin affinity chromatography method (Motohashi et al., 2001). In this study, 37 cytoplasmic proteins were captured as thioredoxin target candidates, including proteins involved in sulfur assimilation. Furthermore, six of the candidate proteins were members of the reductive tricarboxylic acid cycle (pyruvate orthophosphate dikinase, pyruvate flavodoxin/ferredoxin oxidoreductase, ^-oxoglutarate synthase, citrate lyase, citrate synthase, malate dehydrogenase). The redox sensitivity of three enzymes was then examined: citrate lyase, citrate synthase, and malate dehydrogenase, using their recombinant proteins. Based on the information relating to the target proteins, the significance of thioredoxin as a reductant for the metabolic pathway in the anaerobic photosynthetic bacteria is discussed.展开更多
Four kinds of polythiophenes have been doped with CH3SO3H in CHCl3 under air,oxygen,and nitrogen. In the doping of two types of poly(3-hexylthiophene)s,P3HexTh(Zn/Ni)and P3HexTh(Fe)with different contents of a head-to...Four kinds of polythiophenes have been doped with CH3SO3H in CHCl3 under air,oxygen,and nitrogen. In the doping of two types of poly(3-hexylthiophene)s,P3HexTh(Zn/Ni)and P3HexTh(Fe)with different contents of a head-to-tail unit,the p-doping occurs at a similar rate.The reaction between poly(3-dodecylthiophene),P3DodTh,and the acid takes place more rapidly.P3OBuTh with a butoxy substituent undergoes more facile p-doping and receives photochemical reaction with CHCl3,and this reaction obeys a pseudo-first-order rate law with a rate constant kobs of 1.42×10-5s-1at room tempera- ture.展开更多
A new homologous series of isoflavone-based ethers,7-(4-bromoalkyloxy)-3-(4'-decyloxyprienyl)-4H-1-benzopyran-4-ones were synthesized and characterized.The mesomorphic properties of all homologues were investigat...A new homologous series of isoflavone-based ethers,7-(4-bromoalkyloxy)-3-(4'-decyloxyprienyl)-4H-1-benzopyran-4-ones were synthesized and characterized.The mesomorphic properties of all homologues were investigated by differential scanning calorimetry(DSC) and polarizing optical microscopy(POM).Enantiotropic smectic A(SmA) phase was observed for all homologues.The structure-property study was carried out by comparing the mesomorphic behavior of the homologues with those previously reported analogues.The bromine atom from the alkyloxy side chain of the benzene ring fused to the heterocyclic moiety was found to be capable of changing the mesomorphic properties.展开更多
文摘Photochemical reactions of poly(3-butoxythiophene-2,5-diyl) with chloroform under irradiation with light were studied. The reactions were separately carried out under air, oxygen, and nitrogen. The obtained results showed that this reaction belongs to the pseudo-first-order reaction with a rate constant kobs of 1.4×10?5 s?1 at room temperature. The presence or absence of air, oxygen, and nitrogen did not have obvious effects on the reaction rate under irradiation with light.
文摘The present study was conducted with an aim to scale up the production of iturin A using soybean curd residue (okara). Iturin A was produced by indigenous bacterial strain Bacillus subtilis RB14-CS through glass column reactor (GCR) under solid state fermentation (SSF) was characterized. The enhanced iturin A production was observed with respect to enhanced substrate bed height when SSF was conducted in Erlenmeyer flask. To check the effect of substrate bed height on iturin A production under SSF of okara, GCR was introduced. Substrate bed height of 15 cm was suitable for iturin A production which was about 2700 mg/kg wet substrate. The observed iturin A production by the aerobic bacteria Bacillus subtilis in nearly anaerobic condition in such high substrate bed for SSF is a wonderful finding for development of SSF system in future.
文摘Protonating the pyridine rings of poly(pyridine-2,5-diyl) with dodecybenzenesulfonic acid and camphorsulphonic acid produces polymer materials which can be dissolved in chloroform (in contrast to the unprotonated polymer, which can only be dissolved in strong acids such as formic acid) and allows mixing the protonated polymers with other chloroform soluble conju- gated polymers for use in electronic devices. The protonating behavior of poly(pyridine-2,5-diyl) with two kinds of surfactants is different in some levels. Dodecybenzenesulfonic acid has higher protonating ability than camphorsulphonic acid.
文摘NiCl2(bpy) catalyzed polycondensation between p-dibromobenzene and m-dibromobenzene has been carried out under various conditions. The polycondensation endows the copolymer with an M-n of 2300 (by GPC, polystyrene standards) and good solubility in organic solvents. The fluorescence spectra of the copolymer measured with tetrahydrofuran solution shows an emission maximum (lambda(max)) at 372.8 nm, whereas for the film the maximum shifts to 436.6 nm.
基金supported by the National Natural Science Foundation of China(Nos.52122315,21972008)Beijing Nova Program(No.Z201100006820021).
文摘Wettability transition is a significant responsive mechanism which is widely applied to construct smart materials and systems.The broad-spectrum responsiveness of the wettability transition makes it a promising way to expand innovative applications.Here,we develop a track-guided self-transportation system mediated by sequential wettability transition accompanied with capillary transportation.Alkaline fuel is loaded into polydimethylsiloxane(PDMS)cuboid to trigger the wettability transition of distributed superhydrophobic tracks laid in shallow water.After the wettability transition,the induced capillary force can propel the repetitive track-to-track transportation of PDMS.Importantly,the spacing between adjacent tracks is rationally designed based on multiple factors including threshold of wettability transition,diffusion kinetics and capillary interaction.Furthermore,the track-guided transportation system is applied to realize directed self-assembly of multiple PDMS building blocks for designated configuration,which increases the complexity and intelligence of self-assembly systems.
文摘1 Results Helix induction to polymer chains is an active area of research these days. In most cases,optically-active units are attached to the polymers to induce helical conformation. Scheme 1Since the properties of σ-conjugated polymers like polysilanes are dependent on the conformation of the chain,it is particularly interesting to induce helix to oligo-and polysilanes. We have been working on the helix induction by host-guest complexation with sugar derivatives such as cyclodextrine and amylose.The l...
文摘Thioredoxin is a small ubiquitous protein that is involved in the dithiol-disulfide exchange reaction, byway of two cysteine residues located on the molecule surface. In order to elucidate the role of thioredoxin in Chlorobaculum tepidurn, an anaerobic green sulfur bacterium that uses various inorganic sulfur compounds and H2S as electron donors under strict anaerobic conditions for growth, we applied the thioredoxin affinity chromatography method (Motohashi et al., 2001). In this study, 37 cytoplasmic proteins were captured as thioredoxin target candidates, including proteins involved in sulfur assimilation. Furthermore, six of the candidate proteins were members of the reductive tricarboxylic acid cycle (pyruvate orthophosphate dikinase, pyruvate flavodoxin/ferredoxin oxidoreductase, ^-oxoglutarate synthase, citrate lyase, citrate synthase, malate dehydrogenase). The redox sensitivity of three enzymes was then examined: citrate lyase, citrate synthase, and malate dehydrogenase, using their recombinant proteins. Based on the information relating to the target proteins, the significance of thioredoxin as a reductant for the metabolic pathway in the anaerobic photosynthetic bacteria is discussed.
文摘Four kinds of polythiophenes have been doped with CH3SO3H in CHCl3 under air,oxygen,and nitrogen. In the doping of two types of poly(3-hexylthiophene)s,P3HexTh(Zn/Ni)and P3HexTh(Fe)with different contents of a head-to-tail unit,the p-doping occurs at a similar rate.The reaction between poly(3-dodecylthiophene),P3DodTh,and the acid takes place more rapidly.P3OBuTh with a butoxy substituent undergoes more facile p-doping and receives photochemical reaction with CHCl3,and this reaction obeys a pseudo-first-order rate law with a rate constant kobs of 1.42×10-5s-1at room tempera- ture.
基金Universiti Sains Malaysia for USM RU Grants(No.1001/PKIMIA/811127 and 1001/PKIMIA/811140)Chan T.-N.would like to acknowledge USM for the research fellowship
文摘A new homologous series of isoflavone-based ethers,7-(4-bromoalkyloxy)-3-(4'-decyloxyprienyl)-4H-1-benzopyran-4-ones were synthesized and characterized.The mesomorphic properties of all homologues were investigated by differential scanning calorimetry(DSC) and polarizing optical microscopy(POM).Enantiotropic smectic A(SmA) phase was observed for all homologues.The structure-property study was carried out by comparing the mesomorphic behavior of the homologues with those previously reported analogues.The bromine atom from the alkyloxy side chain of the benzene ring fused to the heterocyclic moiety was found to be capable of changing the mesomorphic properties.