[Objective] The aim was to improve the adhesive bonding property of wheat straw surface to prepare wheat straw particleboard of soy protein isolate （SPI） adhesive through chemical and enzyme treatments. [Method] Eva...[Objective] The aim was to improve the adhesive bonding property of wheat straw surface to prepare wheat straw particleboard of soy protein isolate （SPI） adhesive through chemical and enzyme treatments. [Method] Evaluation and analysis were made on wettability of wheat straws in the control group and treated groups （chemical and enzyme treatments） by means of measurement of contact angle and calculation of spreading-penetration parameters （K）. In addition, we made analysis on surface elements through X-ray photoelectron spectroscopy （XPS）. [Result] The re- sults showed that K value of straw treated with sodium hydroxide, hydrogen peroxide and lipase increased by 58.0%, 48.7% and 83.2% compared to that of control group, respectively. The XPS analysis indicated that rapid decrease of silicon content and destruction of wax layer greatly contributed to wettability improvement of wheat straw surface. [Conclusion] The chemical and lipase treatments of wheat straw provided technical support for manufacture of wheat straw particle boand.展开更多
An expression of reflectance of fluorescent dyes in emission region was used in this article. Through the analysis of the spectral radiance factor of fluorescent whitening agents(FWA), the color matching of FWA was st...An expression of reflectance of fluorescent dyes in emission region was used in this article. Through the analysis of the spectral radiance factor of fluorescent whitening agents(FWA), the color matching of FWA was studied and the three-region method of color matching method was put forward. The method was proved to be reliable for the dyes used and was easy to apply for the color matching of FWAs.展开更多
Chrornophore structures inspired by natural green fluorescent protein （GFP） play an im- portant role in the field of bio-irnaging. In this work, photochemical properties of a new class of GFP-like chromophores are i...Chrornophore structures inspired by natural green fluorescent protein （GFP） play an im- portant role in the field of bio-irnaging. In this work, photochemical properties of a new class of GFP-like chromophores are investigated using computational approaches. Thermo- dynamically stable isomers are identified in vacuum and in solvent. Spectral Stokes shifts are computed and compared to experiments. An inverted solvatochromic shift between absorption and emission emerging in this new class of GFP-like chromophores is observed, and attributed to the stabilized charge transfer and inhibited rotational structural reorganization in solvent.展开更多
Embryogenic calli were induced from the seeds of creeping bentgrass ( Agrostis palustris Huds.) cv. Regent and colonial bentgrass ( Agrostis Tenuis Sibth. Fl. Oxen.) cv. Tiger. The embryogenic calli were precult...Embryogenic calli were induced from the seeds of creeping bentgrass ( Agrostis palustris Huds.) cv. Regent and colonial bentgrass ( Agrostis Tenuis Sibth. Fl. Oxen.) cv. Tiger. The embryogenic calli were precultured on fresh medium for 4-7 days and then co cultivated with Agrobacterium tumefaciens , LBA4404, which contains plasmid vector pSBGM harboring bar coding region, synthetic green fluorescent protein (sGFP) coding region and matrix attachment region (MAR). After 3 days of co cultivation, the calli were washed thoroughly and transferred to MS medium containing 2 mg/L of 2, 4 D, 12-15 mg/L phosphinothricin (PPT) and 250 mg/L of cefotaxime. After 2-3 months of selection, the actively growing calli of 'Regent' and 'Tiger' were transferred to MS medium with 12-15 mg/L PPT and 250 mg/L cefotaxime for regeneration. The putative transformants were maintained on MS medium with 3 mg/L PPT for long period but control died within 1 month. After establishing in greenhouse, the transformants also showed strong resistance to 0.4% of herbicide Basta but control plants died within 2 weeks. Under confocal microscope, both young leaves and roots showed significant GFP expression. PCR analysis revealed the presence of a DNA fragment of GFP gene at the expected size (380 bp) in the transformants and its absence in a randomly selected control plant.展开更多
Interaction of a drug molecule with human serum albumin （HSA） is usually studied by fluorescence responses of the ligand or/and the single tryptophan residue （Trp-214） of the protein, but qualitative spectral info...Interaction of a drug molecule with human serum albumin （HSA） is usually studied by fluorescence responses of the ligand or/and the single tryptophan residue （Trp-214） of the protein, but qualitative spectral information may lead to multiple conclusions. In this work, we report a study on the interaction of hematoporphyrin monomethyl ether （HMME） with human serum albumin （HSA）, using the environment-sensitive spectra of HMME and reaction-induced fluorescence response of Trp-214. Particularly, the single kinetic parameter, the linear slope, was derived from the concentration-dependent absorbance or fluorescence of HMME in a certain solvent. A quantitative change in the slope at [HMME]/[HSA] = 1 ： 1 clearly demonstrated a specific binding of HMME to site I. The microenvironment in site I may be comparable to that in DMSO solvent, because of the similarity of the slope. Linear correlation of the fluorescence to the absorbance of HMME in site I indicates that the energy transfer is not responsible for Trp-214 fluorescence quenching but an electron transfer may be possible. In addition, much higher rate observed for the binding of HMME or 2-taurine-substituted HB （THB） with HSA than that of hypocrellin B was due to the electrostatic attraction under physiological condition.展开更多
Eu2+ -activated reddish-orange-emitting Ca3Si2O7 phosphors were synthesized with the addition of NH4Cl flux.When the phosphors were synthesized in a nominal composition of (Ca0.99Eu0.01)3Si2O7 without flux addition,a ...Eu2+ -activated reddish-orange-emitting Ca3Si2O7 phosphors were synthesized with the addition of NH4Cl flux.When the phosphors were synthesized in a nominal composition of (Ca0.99Eu0.01)3Si2O7 without flux addition,a Ca3Si2O7 phase responsible for reddish-orange emission was identified to coexist with an intermediate phase of a-Ca2SiO4 for green emission.With the addition of NH4Cl flux,a-Ca2SiO4 was suppressed while the pure phase Ca3Si2O7 was obtained as the flux content was 3 wt%.Through varying the amount of flux,the emission color of samples can be tuned from green to reddish-orange,corresponding to the phase transformation from a-Ca2SiO4 to Ca3Si2O7.Through optimizing the doping concentration of Eu2+ ,the optimized photoluminescence (PL) properties for reddish-orange emission can be achieved,which makes this kind of phosphor prospective in the applications of the phosphor-converted white light emitting diodes (PC-WLEDs).展开更多
Marine-derived Bacillus strains have been proved to be a very promising source for natural product leads.However,transformation of environmental strains is much more difficult than that of domesticated strains.Here,we...Marine-derived Bacillus strains have been proved to be a very promising source for natural product leads.However,transformation of environmental strains is much more difficult than that of domesticated strains.Here,we report the development of an efficient and robust electroporation-based transformation system for marine-derived Bacillus marinus B-9987,which is a macrolactin antibiotics producer and a very promising biological control agent against fungal plant diseases.The transformation efficiency was greatly enhanced 103-fold by using unmethylated plasmid to bypass modification-restriction barrier,and using glycine betaine to protect cells from electrical damages during electroporation.Addition of HEPES and 2 mmol L?1MgCl2 further improved the efficiency by additional 2-fold,with a maximum value of 7.1×104 cfu/μg pHT3101.To demonstrate the feasibility and efficiency of the protocol,a green fluorescent protein reporter system was constructed;furthermore,phosphopantetheinyl transferase gene sfp,which is essential to the biosynthesis of polyketides and nonribosomal peptides,was overexpressed in B-9987,leading to increased production of macrolactin A by about 1.6-fold.In addition,this protocol is also applicable to marine-derived Bacillus licheniforms EI-34-6,indicating it could be a reference for other undomesticated Bacillus strains.To our knowledge,this is the first report regarding the transformation of marine-derived Bacillus strain.展开更多
For enhancing the emission intensity and broadening the excitation region of Ba3Eu（PO4）3 （BEP）, Sm3＋ is doped as sensitizer in this paper. BEP：Sm3＋ can produce an obvious red emission at near ultraviolet （n-UV...For enhancing the emission intensity and broadening the excitation region of Ba3Eu（PO4）3 （BEP）, Sm3＋ is doped as sensitizer in this paper. BEP：Sm3＋ can produce an obvious red emission at near ultraviolet （n-UV） radiation. An effec- tive energy transfer from Sm3＋ to Eu3＋ is proved. The commission international de I＇Eclairage （CIE） chromaticity co- ordinates of BEP：Sm3＋ locate at red region. When the environment temperature is 150 ℃, the emission intensity of BEP：0.10Sm3＋ is decreased to 76% of the initial one at room temperaatre, and the activation energy is calculated to be 0.164 eV, which can prove the good thermal stability of BEP：Sm3＋. The results indicate that BEP：Sm3＋ may have po- tential applications in white light emitting diodes （LEDs）.展开更多
基金Supported by the Project of Returned Overseas of Harbin Science and Technology Bureau(RC2010LX002005)the Project of Science and Technology Department of Heilongjiang Province(LC07C27)~~
文摘[Objective] The aim was to improve the adhesive bonding property of wheat straw surface to prepare wheat straw particleboard of soy protein isolate （SPI） adhesive through chemical and enzyme treatments. [Method] Evaluation and analysis were made on wettability of wheat straws in the control group and treated groups （chemical and enzyme treatments） by means of measurement of contact angle and calculation of spreading-penetration parameters （K）. In addition, we made analysis on surface elements through X-ray photoelectron spectroscopy （XPS）. [Result] The re- sults showed that K value of straw treated with sodium hydroxide, hydrogen peroxide and lipase increased by 58.0%, 48.7% and 83.2% compared to that of control group, respectively. The XPS analysis indicated that rapid decrease of silicon content and destruction of wax layer greatly contributed to wettability improvement of wheat straw surface. [Conclusion] The chemical and lipase treatments of wheat straw provided technical support for manufacture of wheat straw particle boand.
文摘An expression of reflectance of fluorescent dyes in emission region was used in this article. Through the analysis of the spectral radiance factor of fluorescent whitening agents(FWA), the color matching of FWA was studied and the three-region method of color matching method was put forward. The method was proved to be reliable for the dyes used and was easy to apply for the color matching of FWAs.
基金supported by US National Science Foundation(CHE-1565520) to X. Lifunded by the STF at the University of Washingtonthe National Science Foundation (MRI-1624430).
文摘Chrornophore structures inspired by natural green fluorescent protein （GFP） play an im- portant role in the field of bio-irnaging. In this work, photochemical properties of a new class of GFP-like chromophores are investigated using computational approaches. Thermo- dynamically stable isomers are identified in vacuum and in solvent. Spectral Stokes shifts are computed and compared to experiments. An inverted solvatochromic shift between absorption and emission emerging in this new class of GFP-like chromophores is observed, and attributed to the stabilized charge transfer and inhibited rotational structural reorganization in solvent.
文摘Embryogenic calli were induced from the seeds of creeping bentgrass ( Agrostis palustris Huds.) cv. Regent and colonial bentgrass ( Agrostis Tenuis Sibth. Fl. Oxen.) cv. Tiger. The embryogenic calli were precultured on fresh medium for 4-7 days and then co cultivated with Agrobacterium tumefaciens , LBA4404, which contains plasmid vector pSBGM harboring bar coding region, synthetic green fluorescent protein (sGFP) coding region and matrix attachment region (MAR). After 3 days of co cultivation, the calli were washed thoroughly and transferred to MS medium containing 2 mg/L of 2, 4 D, 12-15 mg/L phosphinothricin (PPT) and 250 mg/L of cefotaxime. After 2-3 months of selection, the actively growing calli of 'Regent' and 'Tiger' were transferred to MS medium with 12-15 mg/L PPT and 250 mg/L cefotaxime for regeneration. The putative transformants were maintained on MS medium with 3 mg/L PPT for long period but control died within 1 month. After establishing in greenhouse, the transformants also showed strong resistance to 0.4% of herbicide Basta but control plants died within 2 weeks. Under confocal microscope, both young leaves and roots showed significant GFP expression. PCR analysis revealed the presence of a DNA fragment of GFP gene at the expected size (380 bp) in the transformants and its absence in a randomly selected control plant.
基金National Natural Science Foundation of China(Grant No.20872144)
文摘Interaction of a drug molecule with human serum albumin （HSA） is usually studied by fluorescence responses of the ligand or/and the single tryptophan residue （Trp-214） of the protein, but qualitative spectral information may lead to multiple conclusions. In this work, we report a study on the interaction of hematoporphyrin monomethyl ether （HMME） with human serum albumin （HSA）, using the environment-sensitive spectra of HMME and reaction-induced fluorescence response of Trp-214. Particularly, the single kinetic parameter, the linear slope, was derived from the concentration-dependent absorbance or fluorescence of HMME in a certain solvent. A quantitative change in the slope at [HMME]/[HSA] = 1 ： 1 clearly demonstrated a specific binding of HMME to site I. The microenvironment in site I may be comparable to that in DMSO solvent, because of the similarity of the slope. Linear correlation of the fluorescence to the absorbance of HMME in site I indicates that the energy transfer is not responsible for Trp-214 fluorescence quenching but an electron transfer may be possible. In addition, much higher rate observed for the binding of HMME or 2-taurine-substituted HB （THB） with HSA than that of hypocrellin B was due to the electrostatic attraction under physiological condition.
基金supported by the National Natural Science Foundation of China (Nos.50872091,21076161 and 50802062)the Tianjin Municipal Science/Technology Commission (Nos.10SYSYJC28100 and 2006ZD30)the Tianjin Municipal Higher Education Commission (No.20110304)
文摘Eu2+ -activated reddish-orange-emitting Ca3Si2O7 phosphors were synthesized with the addition of NH4Cl flux.When the phosphors were synthesized in a nominal composition of (Ca0.99Eu0.01)3Si2O7 without flux addition,a Ca3Si2O7 phase responsible for reddish-orange emission was identified to coexist with an intermediate phase of a-Ca2SiO4 for green emission.With the addition of NH4Cl flux,a-Ca2SiO4 was suppressed while the pure phase Ca3Si2O7 was obtained as the flux content was 3 wt%.Through varying the amount of flux,the emission color of samples can be tuned from green to reddish-orange,corresponding to the phase transformation from a-Ca2SiO4 to Ca3Si2O7.Through optimizing the doping concentration of Eu2+ ,the optimized photoluminescence (PL) properties for reddish-orange emission can be achieved,which makes this kind of phosphor prospective in the applications of the phosphor-converted white light emitting diodes (PC-WLEDs).
基金supported by grants from the National Natural Science Foundation of China (31070072,31171201)the Program for New Century Excellent Talents in University (NCET-0900717)partially supported by the National Key Technologies Research and Development Program (2011BAE06B04)
文摘Marine-derived Bacillus strains have been proved to be a very promising source for natural product leads.However,transformation of environmental strains is much more difficult than that of domesticated strains.Here,we report the development of an efficient and robust electroporation-based transformation system for marine-derived Bacillus marinus B-9987,which is a macrolactin antibiotics producer and a very promising biological control agent against fungal plant diseases.The transformation efficiency was greatly enhanced 103-fold by using unmethylated plasmid to bypass modification-restriction barrier,and using glycine betaine to protect cells from electrical damages during electroporation.Addition of HEPES and 2 mmol L?1MgCl2 further improved the efficiency by additional 2-fold,with a maximum value of 7.1×104 cfu/μg pHT3101.To demonstrate the feasibility and efficiency of the protocol,a green fluorescent protein reporter system was constructed;furthermore,phosphopantetheinyl transferase gene sfp,which is essential to the biosynthesis of polyketides and nonribosomal peptides,was overexpressed in B-9987,leading to increased production of macrolactin A by about 1.6-fold.In addition,this protocol is also applicable to marine-derived Bacillus licheniforms EI-34-6,indicating it could be a reference for other undomesticated Bacillus strains.To our knowledge,this is the first report regarding the transformation of marine-derived Bacillus strain.
基金supported by the National Natural Science Foundation of China(No.50902042)the Natural Science Foundation of Hebei Province in China(Nos.A2014201035 and E2014201037)+1 种基金the Education Office Research Foundation of Hebei Province in China(Nos.ZD2014036 and QN2014085)the College Students Innovation and Entrepreneurship of Hebei University in China(Nos.2014041 and 2015063)
文摘For enhancing the emission intensity and broadening the excitation region of Ba3Eu（PO4）3 （BEP）, Sm3＋ is doped as sensitizer in this paper. BEP：Sm3＋ can produce an obvious red emission at near ultraviolet （n-UV） radiation. An effec- tive energy transfer from Sm3＋ to Eu3＋ is proved. The commission international de I＇Eclairage （CIE） chromaticity co- ordinates of BEP：Sm3＋ locate at red region. When the environment temperature is 150 ℃, the emission intensity of BEP：0.10Sm3＋ is decreased to 76% of the initial one at room temperaatre, and the activation energy is calculated to be 0.164 eV, which can prove the good thermal stability of BEP：Sm3＋. The results indicate that BEP：Sm3＋ may have po- tential applications in white light emitting diodes （LEDs）.
