A regulated gene expression system would offer the unique opportunity to study the gene physiological functions at different developmental stages. For realizing gene special expression in plant anther at given time, w...A regulated gene expression system would offer the unique opportunity to study the gene physiological functions at different developmental stages. For realizing gene special expression in plant anther at given time, we constructed a new system that combined tetracycline- inducible elements with TA29 promoter, a tapetum-specific promoter of tobacco. The system was tested in transient GUS assay system by electroporation (gene gun) transformation of tobacco ( Nicotiana tabacum L. cv. Winsconsin 38) anther. In the absence of tetracycline as the inducer, no GUS activity was detected. However, strong GUS expression was observed in tapetum. tissue upon tetracycline induction, and little GUS activity was found outside the tapetum. Our results suggested that gene expression can be restricted to a specific tissue at the given time under the control of this new system, and this system would be a very useful tool for both basic plant biology research and biotechnological applications.展开更多
Microscopic analysis of the skin and cuticle of wool fibers in Dubska pramenka show different qualitative parameters. The research study included different parts of the body and the samples of the wool fibers from dif...Microscopic analysis of the skin and cuticle of wool fibers in Dubska pramenka show different qualitative parameters. The research study included different parts of the body and the samples of the wool fibers from different regions of the body. Histological description shows difference in the basic structurers of the skin in Dubska pramenka. A very pronounced thin epidermis, while dermis and hypodermis are more developed on the samples from the shoulder. Cornified flakes-cuticle of the root of the tail was of a fine structure, and comified flakes from the rump showed the features of the rough wool fibers. ＂Transitional form of cuticle＂ was dominant on the shoulder. The qualitative parameters have a significant influence on the overall quality of wool in general, and the research contributes to a greater usability value of the wool and development of livestock farming in areas in a broader sense.展开更多
Ever since Lawrence Goodwyn published The Populist Moment, social historians have been keenly aware of the power culture represents when it comes to resistance. Historically, ＂movement culture＂ has been used to crea...Ever since Lawrence Goodwyn published The Populist Moment, social historians have been keenly aware of the power culture represents when it comes to resistance. Historically, ＂movement culture＂ has been used to create a collective climate and offered political activists a springboard to discuss with the masses the benefits of joining a social movement. ＂Beyond the Dreams of Loveliness＂ uses the cultural outlet of film and the labor movement in the city of Detroit as analytical tools to examine working class community resistance throughout the 1930s. In the midst of the ＂golden age of film＂ community activists and union organizers--some of whom were well-known radicals and some of whom were mainstream unionists--used the institution of cinema to instill a level of class consciousness in the masses and mobilize the working class community against exploitation of employers, reactionary politicians, and white supremacist organizations. Movie-going had been a very popular form of recreation in Detroit since the 1920s and downtown theatres increasingly became the destination of an eclectic array of workers. Movie theaters themselves were bastions of community activity around the thirties and many were located in the heart of the city＇s working class district. Yet it was the films themselves that offered community activists and unionists a chance to converse with workers regarding the socio-economic matters of the day. Hollywood released a good number of films that dealt with working class issues and provided activists with ample opportunities to ＂instruct＂ the audience and carry on the discussion into the factory or union halls. ＂Beyond the Dreams of Loveliness＂ relies on a combination of oral histories, movie reviews, film clips, and union and/or working class organizational records to illuminate how activists in Detroit＇s working class community used film as an outlet to inspire working class resistance. In sum, film provided an accessible form of entertainment that proved to be effective on two fronts： It promoted increased group cooperation, friendship, and alliances while it also fostered a shared culture, making it easier for activists to organize workers in the coming struggles for unionism.展开更多
In order to investigate the influence of three key molar ratios （n（SiO2）/n（Al2O3）, n（K2O）/n（Al2O3） and n（H2O）/n（K2O））, a total of nine potassium poly-sialate-disiloxo （K-PSDS） geopolymeric cement matri...In order to investigate the influence of three key molar ratios （n（SiO2）/n（Al2O3）, n（K2O）/n（Al2O3） and n（H2O）/n（K2O））, a total of nine potassium poly-sialate-disiloxo （K-PSDS） geopolymeric cement matrices were designed according to orthogonal design principle. Subsequently, XRD, ESEM-EDXA and MAS-NMR techniques were employed to further characterize the microstructure of the most fully reacted geopolymeric cement matrix. The experimental results show that n（K2O）/n（Al2O3） has the most significant effect on compressive strength amongst the three ratios. The highest compressive strength （20.1 MPa） can be achieved when n（SiO2）/n（Al2O3）=6.5, n（K2O）/n（Al2O3）=0.8 and n（HEO）/n（K2O）=10.0. The FTIR spectra of nine PSDS geopolymeric cement matrices also indicate that geopolymeric cement matrix with the highest strength is the most fully reacted one and possesses the largest amount of geopolymeric cement products. The microscopic analysis reveals that PSDS geopolymeric cement matrix possesses structural characteristics similar to gel substances in having a wide range of Si endowments, but predominantly the framework molecular chains of Si partially replaced by 4-coordinated Al tetrahedral.展开更多
The study used a naturally occurring crosslinking reagent-genipin to chemically modify acellular bovine pericardium, prepare cardiac valve tissue engineering scaffold material,and evaluated genipin crosslinked acellul...The study used a naturally occurring crosslinking reagent-genipin to chemically modify acellular bovine pericardium, prepare cardiac valve tissue engineering scaffold material,and evaluated genipin crosslinked acellular matrix of bovine pericardium by investigating the physical and chemical properties of the tissues, such as the surface properties, crosslinking characteristics, mechanical properties, resistance to enzymatic capacity in vitro, and hemolysis tests. The results showed that acellular bovine pericardium matrix erosslinked with genipin was strong hydrophilicity, high crosslinking index, and stable structure, which can maintain good mechanical properties. As a kind of scaffold material for valve tissue engineering, it has wide application prospect.展开更多
文摘A regulated gene expression system would offer the unique opportunity to study the gene physiological functions at different developmental stages. For realizing gene special expression in plant anther at given time, we constructed a new system that combined tetracycline- inducible elements with TA29 promoter, a tapetum-specific promoter of tobacco. The system was tested in transient GUS assay system by electroporation (gene gun) transformation of tobacco ( Nicotiana tabacum L. cv. Winsconsin 38) anther. In the absence of tetracycline as the inducer, no GUS activity was detected. However, strong GUS expression was observed in tapetum. tissue upon tetracycline induction, and little GUS activity was found outside the tapetum. Our results suggested that gene expression can be restricted to a specific tissue at the given time under the control of this new system, and this system would be a very useful tool for both basic plant biology research and biotechnological applications.
文摘Microscopic analysis of the skin and cuticle of wool fibers in Dubska pramenka show different qualitative parameters. The research study included different parts of the body and the samples of the wool fibers from different regions of the body. Histological description shows difference in the basic structurers of the skin in Dubska pramenka. A very pronounced thin epidermis, while dermis and hypodermis are more developed on the samples from the shoulder. Cornified flakes-cuticle of the root of the tail was of a fine structure, and comified flakes from the rump showed the features of the rough wool fibers. ＂Transitional form of cuticle＂ was dominant on the shoulder. The qualitative parameters have a significant influence on the overall quality of wool in general, and the research contributes to a greater usability value of the wool and development of livestock farming in areas in a broader sense.
文摘Ever since Lawrence Goodwyn published The Populist Moment, social historians have been keenly aware of the power culture represents when it comes to resistance. Historically, ＂movement culture＂ has been used to create a collective climate and offered political activists a springboard to discuss with the masses the benefits of joining a social movement. ＂Beyond the Dreams of Loveliness＂ uses the cultural outlet of film and the labor movement in the city of Detroit as analytical tools to examine working class community resistance throughout the 1930s. In the midst of the ＂golden age of film＂ community activists and union organizers--some of whom were well-known radicals and some of whom were mainstream unionists--used the institution of cinema to instill a level of class consciousness in the masses and mobilize the working class community against exploitation of employers, reactionary politicians, and white supremacist organizations. Movie-going had been a very popular form of recreation in Detroit since the 1920s and downtown theatres increasingly became the destination of an eclectic array of workers. Movie theaters themselves were bastions of community activity around the thirties and many were located in the heart of the city＇s working class district. Yet it was the films themselves that offered community activists and unionists a chance to converse with workers regarding the socio-economic matters of the day. Hollywood released a good number of films that dealt with working class issues and provided activists with ample opportunities to ＂instruct＂ the audience and carry on the discussion into the factory or union halls. ＂Beyond the Dreams of Loveliness＂ relies on a combination of oral histories, movie reviews, film clips, and union and/or working class organizational records to illuminate how activists in Detroit＇s working class community used film as an outlet to inspire working class resistance. In sum, film provided an accessible form of entertainment that proved to be effective on two fronts： It promoted increased group cooperation, friendship, and alliances while it also fostered a shared culture, making it easier for activists to organize workers in the coming struggles for unionism.
基金Project(2009CB623200) supported by the National Basic Research Program of ChinaProjects(50702014, 50878043) supported by the National Natural Science Foundation of ChinaProject(NCET-08-0116) supported by the Program for New Century Excellent Talents in University of Ministry of Education, China
文摘In order to investigate the influence of three key molar ratios （n（SiO2）/n（Al2O3）, n（K2O）/n（Al2O3） and n（H2O）/n（K2O））, a total of nine potassium poly-sialate-disiloxo （K-PSDS） geopolymeric cement matrices were designed according to orthogonal design principle. Subsequently, XRD, ESEM-EDXA and MAS-NMR techniques were employed to further characterize the microstructure of the most fully reacted geopolymeric cement matrix. The experimental results show that n（K2O）/n（Al2O3） has the most significant effect on compressive strength amongst the three ratios. The highest compressive strength （20.1 MPa） can be achieved when n（SiO2）/n（Al2O3）=6.5, n（K2O）/n（Al2O3）=0.8 and n（HEO）/n（K2O）=10.0. The FTIR spectra of nine PSDS geopolymeric cement matrices also indicate that geopolymeric cement matrix with the highest strength is the most fully reacted one and possesses the largest amount of geopolymeric cement products. The microscopic analysis reveals that PSDS geopolymeric cement matrix possesses structural characteristics similar to gel substances in having a wide range of Si endowments, but predominantly the framework molecular chains of Si partially replaced by 4-coordinated Al tetrahedral.
基金National High-tech Research and Development Program(836 Prgoram) of Chinagrant number:2007AA02Z444+1 种基金National BasicProgram of China (973 Program)grant number:2009CB930000
文摘The study used a naturally occurring crosslinking reagent-genipin to chemically modify acellular bovine pericardium, prepare cardiac valve tissue engineering scaffold material,and evaluated genipin crosslinked acellular matrix of bovine pericardium by investigating the physical and chemical properties of the tissues, such as the surface properties, crosslinking characteristics, mechanical properties, resistance to enzymatic capacity in vitro, and hemolysis tests. The results showed that acellular bovine pericardium matrix erosslinked with genipin was strong hydrophilicity, high crosslinking index, and stable structure, which can maintain good mechanical properties. As a kind of scaffold material for valve tissue engineering, it has wide application prospect.
