T cells are derived from progenitor thymocytes, of which only a minority receive the appropriate TCR signal, undergo positive selection and mature. Owing to the very short lifespan of thymocytes, the prerequisite for ...T cells are derived from progenitor thymocytes, of which only a minority receive the appropriate TCR signal, undergo positive selection and mature. Owing to the very short lifespan of thymocytes, the prerequisite for posi- tive selection is survival. TCR signal-induced Bcl-2 expression is believed to play a dominant role in the survival of positively selecting thymocytes, but how Bcl-2 is directly regulated is unknown. Here we report that the immediate early gene （IEG） c-Fos can stimulate the expression of Bcl-2, depending on a specific AP-l-binding site in the Bcl-2 promoter. In c-Fos transgenic （Fos-Tg） mice, c-Fos binds to this site and promotes the expression of Bcl-2. As a result, Fos-Tg thymocytes exhibited enhanced survival, and more mature single-positive （SP） thymocytes were generated, even on a unique TCR background. The TCR repertoire remained normal in Fos-Tg mice. Our results identified c-Fos as the mediator of the stimulatory effect of TCR signaling on Bcl-2 expression. Therefore, c-Fos, as an IEG, because of its early response ability, can quickly rescue the survival of short-lived thymocytes during positive selection. Our results provide novel insight into the mechanism regulating the survival of positively selecting thymocytes.展开更多
In this paper,we find a subclass of starlike functions on the unit disk,which are mapped by a operator,given by F（z）=1＋u/zu∫z0 f（t）tu-1dt（Re u≥0）,onto convex functions.The main results extend some known results.
Transcatheter aortic valve implantation （TAV1） represents a real revolution in the field of interventional cardiology for the treatment of elderly or high-risk surgical patients with severe symptomatic aortic valve ...Transcatheter aortic valve implantation （TAV1） represents a real revolution in the field of interventional cardiology for the treatment of elderly or high-risk surgical patients with severe symptomatic aortic valve stenosis. Today, TAVI seems to play a key and a reliable role in the treatment of intermediate and maybe low-risk patients with severe aortic stenosis. TAVI has also evolved from a complex and hazardous procedure into an effective and safe therapy by the development of new generation devices. This article aims to review the background and future of TAVI, elinieal trials and registries with old and new generation TAVI devices and to focus on some open issues related to post-procedural outcomes.展开更多
In the 21st century, the South Korean government is to develop its own cultural industries, and it has achieved great results. Since the administration of President Chun Doo-hwan, it started the Korean government for ...In the 21st century, the South Korean government is to develop its own cultural industries, and it has achieved great results. Since the administration of President Chun Doo-hwan, it started the Korean government for the development of cultural industry that has formulated a series of policies, laws and regulations, which is the development of Korean culture industry that has played a positive role in promoting. By analyzing the current development of cultural industries in Korea, Korean culture industry can be seen with the following characteristics in the development process, ie government-led industrial policy and cultural economic and non-economic nature of double and capital, talent and technology for the development of cultural industries powered. Successful experience in development and operation of Korean culture of industry development has an important enlightenment on China＇ s cultural industry.展开更多
The surface of nanocrystals plays a dominant role in many of their physical and chemical properties.However,controllability and tunability of nanocrystal surfaces remain unsolved.Herein,we report that the surface chem...The surface of nanocrystals plays a dominant role in many of their physical and chemical properties.However,controllability and tunability of nanocrystal surfaces remain unsolved.Herein,we report that the surface chemistry of nanocrystals,such as near-infrared Ag_(2)Se quantum dots(QDs),is sizedependent and composition-tunable.The Ag_(2)Se QDs tend to form a stable metal complex on the surface to minimize the surface energy,and therefore the surface chemistry can be varied with particle size.Meanwhile,changes in surface inorganic composition lead to reorganization of the surface ligands,and the surface chemistry also varies with composition.Therefore,the surface chemistry of Ag_(2)Se QDs,responsible for the photoluminescence(PL)quantum yield and photostability,can be tuned by changing their size or composition.Accordingly,we demonstrate that the PL intensity of the Ag_(2)Se QDs can be tuned reversely by adjusting the degree of surface Ag^(+) enrichment via light irradiation or the addition of AgNO_(3).This work provides insight into the control of QD surface for desired PL properties.展开更多
The widespread communications between prokaryotes and eukaryotes via signaling molecules are believed to affect gene expression in both partners.During the communication process,the contacted organisms produce and rel...The widespread communications between prokaryotes and eukaryotes via signaling molecules are believed to affect gene expression in both partners.During the communication process,the contacted organisms produce and release small molecules that establish communication channels between two kingdoms—this procedure is known as interkingdom signaling.Interkingdom communications are widespread between pathogenic or beneficial bacteria and their host plants,with diversified outcomes depending on the specific chemical-triggered signaling pathways.Deciphering the signals or language of this interkingdom communication and uncovering the underlying mechanisms are major current challenges in this field.It is evident that diverse signaling molecules can be produced or derived from bacteria and plants,and researchers have sought to identify these signals and explore the mechanisms of the signaling pathways.The results of such studies will lead to the development of strategies to improve plant disease resistance through controlling interkingdom signals,rather than directly killing the pathogenic bacteria.Also,the identification of signals produced by beneficial bacteria will be useful for agricultural applications.In this review,we summarize the recent progress of cross-kingdom interactions between plant and bacteria,and how LuxR-family transcription factors in plant associated bacterial quorum sensing system are involved in the interkingdom signaling.展开更多
文摘T cells are derived from progenitor thymocytes, of which only a minority receive the appropriate TCR signal, undergo positive selection and mature. Owing to the very short lifespan of thymocytes, the prerequisite for posi- tive selection is survival. TCR signal-induced Bcl-2 expression is believed to play a dominant role in the survival of positively selecting thymocytes, but how Bcl-2 is directly regulated is unknown. Here we report that the immediate early gene （IEG） c-Fos can stimulate the expression of Bcl-2, depending on a specific AP-l-binding site in the Bcl-2 promoter. In c-Fos transgenic （Fos-Tg） mice, c-Fos binds to this site and promotes the expression of Bcl-2. As a result, Fos-Tg thymocytes exhibited enhanced survival, and more mature single-positive （SP） thymocytes were generated, even on a unique TCR background. The TCR repertoire remained normal in Fos-Tg mice. Our results identified c-Fos as the mediator of the stimulatory effect of TCR signaling on Bcl-2 expression. Therefore, c-Fos, as an IEG, because of its early response ability, can quickly rescue the survival of short-lived thymocytes during positive selection. Our results provide novel insight into the mechanism regulating the survival of positively selecting thymocytes.
基金Supported by the National Natural Science Foundation of Mathematics Tianyuan Fund（A0524629）
文摘In this paper,we find a subclass of starlike functions on the unit disk,which are mapped by a operator,given by F（z）=1＋u/zu∫z0 f（t）tu-1dt（Re u≥0）,onto convex functions.The main results extend some known results.
文摘Transcatheter aortic valve implantation （TAV1） represents a real revolution in the field of interventional cardiology for the treatment of elderly or high-risk surgical patients with severe symptomatic aortic valve stenosis. Today, TAVI seems to play a key and a reliable role in the treatment of intermediate and maybe low-risk patients with severe aortic stenosis. TAVI has also evolved from a complex and hazardous procedure into an effective and safe therapy by the development of new generation devices. This article aims to review the background and future of TAVI, elinieal trials and registries with old and new generation TAVI devices and to focus on some open issues related to post-procedural outcomes.
文摘In the 21st century, the South Korean government is to develop its own cultural industries, and it has achieved great results. Since the administration of President Chun Doo-hwan, it started the Korean government for the development of cultural industry that has formulated a series of policies, laws and regulations, which is the development of Korean culture industry that has played a positive role in promoting. By analyzing the current development of cultural industries in Korea, Korean culture industry can be seen with the following characteristics in the development process, ie government-led industrial policy and cultural economic and non-economic nature of double and capital, talent and technology for the development of cultural industries powered. Successful experience in development and operation of Korean culture of industry development has an important enlightenment on China＇ s cultural industry.
基金supported by the National Natural Science Foundation of China(91859123)the National Key R&D Program of China(2019YFA0210103)。
文摘The surface of nanocrystals plays a dominant role in many of their physical and chemical properties.However,controllability and tunability of nanocrystal surfaces remain unsolved.Herein,we report that the surface chemistry of nanocrystals,such as near-infrared Ag_(2)Se quantum dots(QDs),is sizedependent and composition-tunable.The Ag_(2)Se QDs tend to form a stable metal complex on the surface to minimize the surface energy,and therefore the surface chemistry can be varied with particle size.Meanwhile,changes in surface inorganic composition lead to reorganization of the surface ligands,and the surface chemistry also varies with composition.Therefore,the surface chemistry of Ag_(2)Se QDs,responsible for the photoluminescence(PL)quantum yield and photostability,can be tuned by changing their size or composition.Accordingly,we demonstrate that the PL intensity of the Ag_(2)Se QDs can be tuned reversely by adjusting the degree of surface Ag^(+) enrichment via light irradiation or the addition of AgNO_(3).This work provides insight into the control of QD surface for desired PL properties.
基金supported by National Basic Research Program of China(2015B150600)National Key R&D Program(2016YFD0100600)National Natural Science Foundation of China(31370161)
文摘The widespread communications between prokaryotes and eukaryotes via signaling molecules are believed to affect gene expression in both partners.During the communication process,the contacted organisms produce and release small molecules that establish communication channels between two kingdoms—this procedure is known as interkingdom signaling.Interkingdom communications are widespread between pathogenic or beneficial bacteria and their host plants,with diversified outcomes depending on the specific chemical-triggered signaling pathways.Deciphering the signals or language of this interkingdom communication and uncovering the underlying mechanisms are major current challenges in this field.It is evident that diverse signaling molecules can be produced or derived from bacteria and plants,and researchers have sought to identify these signals and explore the mechanisms of the signaling pathways.The results of such studies will lead to the development of strategies to improve plant disease resistance through controlling interkingdom signals,rather than directly killing the pathogenic bacteria.Also,the identification of signals produced by beneficial bacteria will be useful for agricultural applications.In this review,we summarize the recent progress of cross-kingdom interactions between plant and bacteria,and how LuxR-family transcription factors in plant associated bacterial quorum sensing system are involved in the interkingdom signaling.
