The SAPO‐34 catalysts were modified with metal cations by different processes(conventional ion exchange(CIE),template‐assisted ion incorporation(TII)and alcoholic ion exchange(AIE)),systematically characterized by X...The SAPO‐34 catalysts were modified with metal cations by different processes(conventional ion exchange(CIE),template‐assisted ion incorporation(TII)and alcoholic ion exchange(AIE)),systematically characterized by XRD,XRF,N2 adsorption‐desorption,UV‐VIS,H2‐TPR,EPR,SEM,EDX,XPS,NH3‐TPD,1H NMR and IGA,and applied in MTO reaction.The metal cations incorporation introduces extra diffusion hindrance by metallic species located in the cavity of SAPO‐34.In particular,the Zn cations‐modified SAPO‐34 catalysts exhibit core‐shell like structure,with Si‐rich and Zn‐rich sublayer near the external surface,which favors the coke deposition at the beginning of MTO reaction,exerts marked impact on the diffusion of the generated products with relatively large molecular size(e.g.propylene),and significantly increases the selectivity to ethylene and the ratio of ethylene to propene in the MTO reaction.展开更多
Pressureless infiltration process to synthesize Si3N4/Al composite was investigated. Al-2%Mg alloy was infiltrated into Si3N4 and Si3N4 containing 10% Al2O3 preforms in the atmosphere of nitrogen. It is possible to in...Pressureless infiltration process to synthesize Si3N4/Al composite was investigated. Al-2%Mg alloy was infiltrated into Si3N4 and Si3N4 containing 10% Al2O3 preforms in the atmosphere of nitrogen. It is possible to infiltrate Al-2%Mg alloy in Si3N4 and Si3N4 containing 10% Al2O3 preforms. The growth of the dense composite of useful thickness was facilitated by the presence of magnesium powder at the interface and by flowing nitrogen. During infiltration Si3N4 reacted with aluminium to form Si and AlN, the growth of composite was found to proceed in two ways, depending on the Al2O3 content in the initial preform. Firstly, preform without Al2O3 content gives rise to AlN, Al3.27Si0.47 and Al type phases after infiltration. Secondly, perform with 10% Al2O3 content gives rise to AlN-Al2O3 solid solution phase (AlON), MgAl2O4, Al and Si type phases. AlON phase was only present in composite, containing 10% Al2O3 in the Si3N4 preforms before infiltration.展开更多
Four types of apatite have been identified in the Ningwu region. The first type of apatite is widely distributed in the middle dark colored zones （i.e. iron ores） of individual deposits. The assemblage includes magn...Four types of apatite have been identified in the Ningwu region. The first type of apatite is widely distributed in the middle dark colored zones （i.e. iron ores） of individual deposits. The assemblage includes magnetite, apatite and actinolite （or diopside）. The second type occurs within magnetite-apatite veins in the iron ores. The third type is seen in magnetite-apatite veins and （or） nodules in host rocks （i.e. gabbro-diorite porphyry or gabbro-diorite or pyroxene diorite）.The fourth type occurs within apatite-pyrite-quartz veins f＇dfing fractures in the Xiangshan Group. Rare earth elements （REE） geochemistry of apatite of the four occurrences in porphyry iron deposits is presented. The REE distribution patterns of apatite are generally similar to those of apatites in the Kiruna-type iron ores, nelsonites. They are enriched in fight REE, with pronounced negative Eu anomalies. The similarity of REE distribution patterns in apatites from various deposits in different locations in the world indicates a common process of formation for various ore types, e.g. immiscibility. Early magmatic apatites contain 3031.48-12080 ×10^-6 REE. Later hydrothermal apatite contains 1958 ×10^-6 REE, indicating that the later hydrothermal ore-forming solution contains lower REE. Although gabbro-diorite porphyry and apatite show similar REE patterns, gabbro-diorite porphyries have no europium anomalies or feeble positive or feeble negative europium anomalies, caused both by reduction environment of mantle source region and by fractionation and crystallization （immiscibility） under a high oxygen fugacity condition. Negative Eu anomalies of apatites were formed possibly due to acquisition of Eu^2＋ by earlier diopsite during ore magma cooling. The apatites in the Aoshan and Taishan iron deposits yield a narrow variation range of ^87Sr/^86Sr values from 0.7071 to 0.7073, similar to those of the volcanic and subvolcaulc rocks, indicating that apatites were formed by liquid immiscibility and differentiation 展开更多
The Qinling Mountains is not only the geographical boundary between North and South China,but also the boundary between subtropical and warm temperate zones.It plays an important role in the geo-ecological pattern of ...The Qinling Mountains is not only the geographical boundary between North and South China,but also the boundary between subtropical and warm temperate zones.It plays an important role in the geo-ecological pattern of China.However,there is controversy about the specific location of this geographical boundary in academic community due to the complexity,transition and heterogeneity of the transitional zone,as well as the differences in the delimitation indicators and research purposes.To further reveal the characteristics of the North-South transitional zone and clarify the specific location of the geo-ecological boundary between North and South China,combined with SRTM topographic data,temperature and precipitation data,Pinus massoniana forest and Pinus tabulaeformis forest,which represent subtropical coniferous forest in South China and temperate coniferous forest in North China respectively,were chosen to analyze their spatial distributions in the Qinling-Daba Mountains and the climatic conditions at their boundary with the climatic indexes of annual precipitation,the coldest month(January) average temperature,the warmest month(July) average temperature and the annual average temperature.The results show that:(1) Pinus massoniana and Pinus tabulaeformis forests and the climate indicators of their boundary can be used as one of the vegetation-climate indexes for the delimitation of subtropical and warm temperate zones.The boundary between the subtropical coniferous forest(Pinus massoniana forest) and temperate coniferous forest(Pinus tabulaeformis forest) is located along the south slope of Funiu Mountain to the north edge of Hanzhong Basin(the south slope of Qinling Mountains) at an altitude of 1000–1200 m,where the climatic indictors are stable:the annual precipitation is about 750–1000 mm,the annual average temperature is about 12–14℃,the coldest monthly average temperature is 0–4℃,and the warmest monthly average temperature is about 22–26℃.(2) It can be more scientifically to delimitate the bo展开更多
Dear Editor,Over a half-century ago,Dr.Leonard Hayflick described the phenotype of a finite lifespan for human fibroblasts being passaged in in vitro cell culture(Hayflick et al.,1961),a phenomenon today known as repl...Dear Editor,Over a half-century ago,Dr.Leonard Hayflick described the phenotype of a finite lifespan for human fibroblasts being passaged in in vitro cell culture(Hayflick et al.,1961),a phenomenon today known as replicative cellular senescence.Cellular senescence has been defined as a state in which cells lose their potential to divide and are permanently arrested in either the G1,or arguably the G2 stage of the cell cycle(Mao et al.,2012).In addition to replicative cellular senescenee—which is induced by large amounts of DNA damage at telomeres due to loss of the specialized T-loop structure—xogenous sublethal stresses such as ionizing radiati on,genotoxic chemicals or hyper-activated on cogenes may also trigger a similar form of senescence,stress induced premature cellular senescenee(SIPS).展开更多
Focusing on the reform initiatives of Chinese Academy of Medical Sciences(CAMS) & Peking Union Medical College(PUMC) in medical scientific and technological innovation from perspectives of deepening the reform and...Focusing on the reform initiatives of Chinese Academy of Medical Sciences(CAMS) & Peking Union Medical College(PUMC) in medical scientific and technological innovation from perspectives of deepening the reform and optimizing the ecosystem of science and technology innovation,this article summarizes the highlights of CAMS & PUMC’s efforts in safeguarding people’ s health and promoting the Healthy China 2030 strategy through scientific and technological innovation in the fields including basic research,disease prevention and treatment,and medical technology in the past ten years.These achievements embody the endeavors and responsibility of CAMS& PUMC in realizing self-reliance and self-improvement of Chinese medical science and technology and highlight its contributions to the development of medical science and technology of China.展开更多
Plant immunity is controlled by both positive regulators such as PBS3 and EDS1 and negative regulators such as NPR3 and NPR4.However,the relationships among these important immune regulators remain elusive.In this stu...Plant immunity is controlled by both positive regulators such as PBS3 and EDS1 and negative regulators such as NPR3 and NPR4.However,the relationships among these important immune regulators remain elusive.In this study,we found that PBS3 interacts with EDS1 in both the cytoplasm and the nucleus,and is required for EDS1 protein accumulation?NPR3 and NPR4,which function as salicylic acid receptors and adaptors of Cullin3-based E3 ligase,interact with and mediate the degradation of EDS1 via the 26S proteasome.We further discovered that PBS3 inhibits the polyubiquitination and subsequent degradation of EDS1 by reducing the association of EDS1 with the Cullin3 adaptors NPR3 and NPR4.Furthermore,we showed that PBS3 and EDS1 also contribute to PAMP-triggered immunity in addition to effector-triggered immunity.Collectively,our study reveals a novel mechanism by which plants fine-tune defense resporises by inhibiting the degradation of a positive player in plant immunity.展开更多
The influences of a 0.2 T static magnetic field on the microstructure of 7075 aluminum alloys sheets produced with a twin-roll continuous caster at 675℃ were investigated in this paper. Under a uniform magnetic field...The influences of a 0.2 T static magnetic field on the microstructure of 7075 aluminum alloys sheets produced with a twin-roll continuous caster at 675℃ were investigated in this paper. Under a uniform magnetic field, the primary dendrites were refined and tended to be equiaxed. The microstructure consisted of an intermediate case between dendritic and equiaxed grains. Moreover, the use of an external static field in the twin-roll casting process can reduce heat discharge, resulting in a decrease in undercooling, and may also account for the abatement of segregation bands. In addition, the static magnetic field effectively improved the solute mixing capacity, and the added atoms more easily diffused from precipitates to theα-Al matrix, which resulted in an increase in the mechanical properties of the rolled sheets. Specimens prepared both in the presence of a static magnetic field and in the absence of a static magnetic field exhibited brittle-fracture characteristics.展开更多
A computer simulation model of salt pan is presented.The transient behavior and the effects of various parameters of the salt pans,such as the depth of the brine layer,the absorptance of the soil surface,the thermal p...A computer simulation model of salt pan is presented.The transient behavior and the effects of various parameters of the salt pans,such as the depth of the brine layer,the absorptance of the soil surface,the thermal properties of the soil beneath the brine layer and the depth of the underground water table,on the evaporation process of salt pans are discussed.The effects of extra insulation layer and the intensity of solar radiation are also examined.展开更多
Dear Editor,L-Fucose(6-deoxy-L-galactose,fucose)is the basic compone nt of a variety of glyca n structures.The fucosylated oligosaccharides participate in a variety of cellular activities,like the cell-cell recognitio...Dear Editor,L-Fucose(6-deoxy-L-galactose,fucose)is the basic compone nt of a variety of glyca n structures.The fucosylated oligosaccharides participate in a variety of cellular activities,like the cell-cell recognition,selectin-mediated leukocyteendothelial adhesion and the formation of Lewis blood group antigens(Ma et al.,2006).GDP-fucose is an important fucose donor in the process of fucosylated oligosaccharides formation.Two pathways of GDP-fucose synthesis are present in the cytosol of mammalian cells,including the de novo pathway and the salvage pathway(Becker et al.,2003).In the salvage pathway,cells use fucose from the extracellular or lysosomal sources to synthesize GDP-fucose.展开更多
There has been much progress in the study of tropical cyclones and tropical meteorology in China in the past few years. A new atmospheric field experiment of tropical cyclone landfall with the acronym of CLATEX (China...There has been much progress in the study of tropical cyclones and tropical meteorology in China in the past few years. A new atmospheric field experiment of tropical cyclone landfall with the acronym of CLATEX (China Landfalling Typhoon Experiment) was implemented in July-August 2002. The boundary layer characteristics of the target typhoon Vongfong and the mesoscale structural features of other land-falling typhoons were studied. In addition, typhoon track operational forecasting errors in the last decade have been reduced because the operational monitoring equipment and forecast techniques were improved. Some results from the research program on tropical cvclone landfall, structure and intensity change, inten-sification near coastal waters, interaction between tropical cyclone and mid-latitude circulation, and the interaction among different scales of motion are described in this paper. Four major meteorological scien-tific experiments in China with international cooperation were implemented in 1998: the South China Sea monsoon field experiment (SCSMEX), the Tibetan Plateau field experiment (TIPEX), the Huaihe River basin energy and water cycle experiment (HUBEX), and the South China heavy rain scientific experiment (HUAMEX). Although these field experiments have different scientific objectives, they commonly relate to monsoon activities and they interact with each other. The valuable intensive observation data that were obtained have already been shared internationally. Some new findings have been published recently. Other research work in China, such as the tropical air-sea interaction, tropical atmospheric circulation, and weather systems, are reviewed in this paper as well. Some research results have shown that the rainfall anomalies for different regions in China were closely related to the stages of El Nino events.展开更多
Orobanche spp. （broomrapes） are holoparasitic plants distributed predominantly in the Northern Hemisphere parasitizing the roots of a range of plant species mainly in wild ecosystems. Orobanche species cause severe ...Orobanche spp. （broomrapes） are holoparasitic plants distributed predominantly in the Northern Hemisphere parasitizing the roots of a range of plant species mainly in wild ecosystems. Orobanche species cause severe yield reduction of many important crops. There are only very few herbicides which are able to selectively control broomrapes and different approaches have been put forward to develop natural product based pesticides to control Orobanche. Several phytopathogenic fungi were evaluated for their use as potential mycoherbicide and for ability to produce toxic metabolites which could be applied as herbicides. Using the alternative approach ＂suicidal germination＂, interesting results were obtained by testing two microbial metabolites （fusicoccins and ophiobolin A） especially with Orobanche species whose germination is not induced by the synthetic strigolactone GR24. From pea root exudates, peagol and peagoldione, close related to strigolactones, and three polyphenols, named peapolyphenols A-C, together with already well known polyphenol and a chalcone, were isolated. They showed a selective stimulation of Orobanche seed germination with the last two and peapolyphenol A showing a specific stimulatory activity on O. foetida. This review describes the most recent results achieved on Orobanche bio-control, mainly focusing on those regarding O. ramosa, O. crenata and O. foetida.展开更多
Ataxia with oculomotor apraxia type 1 (AOA1) is an autosomal recessive disorde r characterized by earlyonset cerebellar ataxia, oculomotor apraxia, and perip heral neuropathy. The causative gene (APTX) has been rece...Ataxia with oculomotor apraxia type 1 (AOA1) is an autosomal recessive disorde r characterized by earlyonset cerebellar ataxia, oculomotor apraxia, and perip heral neuropathy. The causative gene (APTX) has been recently identified in Port uguese and Japanese kindreds. Three patients with AOA1 were identified in an APT X mutation screening on 28 Southern Italian patients with progressive ataxia and peripheral neuropathy. A novel homozygous missense mutation (H201Q) was found i n one patient and a Japanese missense mutation (P206L) in two. AOA1 clinical het erogeneity and onset later than previously described are shown.展开更多
文摘The SAPO‐34 catalysts were modified with metal cations by different processes(conventional ion exchange(CIE),template‐assisted ion incorporation(TII)and alcoholic ion exchange(AIE)),systematically characterized by XRD,XRF,N2 adsorption‐desorption,UV‐VIS,H2‐TPR,EPR,SEM,EDX,XPS,NH3‐TPD,1H NMR and IGA,and applied in MTO reaction.The metal cations incorporation introduces extra diffusion hindrance by metallic species located in the cavity of SAPO‐34.In particular,the Zn cations‐modified SAPO‐34 catalysts exhibit core‐shell like structure,with Si‐rich and Zn‐rich sublayer near the external surface,which favors the coke deposition at the beginning of MTO reaction,exerts marked impact on the diffusion of the generated products with relatively large molecular size(e.g.propylene),and significantly increases the selectivity to ethylene and the ratio of ethylene to propene in the MTO reaction.
文摘Pressureless infiltration process to synthesize Si3N4/Al composite was investigated. Al-2%Mg alloy was infiltrated into Si3N4 and Si3N4 containing 10% Al2O3 preforms in the atmosphere of nitrogen. It is possible to infiltrate Al-2%Mg alloy in Si3N4 and Si3N4 containing 10% Al2O3 preforms. The growth of the dense composite of useful thickness was facilitated by the presence of magnesium powder at the interface and by flowing nitrogen. During infiltration Si3N4 reacted with aluminium to form Si and AlN, the growth of composite was found to proceed in two ways, depending on the Al2O3 content in the initial preform. Firstly, preform without Al2O3 content gives rise to AlN, Al3.27Si0.47 and Al type phases after infiltration. Secondly, perform with 10% Al2O3 content gives rise to AlN-Al2O3 solid solution phase (AlON), MgAl2O4, Al and Si type phases. AlON phase was only present in composite, containing 10% Al2O3 in the Si3N4 preforms before infiltration.
基金This paper is financially aided by the National Natural Science Foundation of China （Grant No. 40472055）.
文摘Four types of apatite have been identified in the Ningwu region. The first type of apatite is widely distributed in the middle dark colored zones （i.e. iron ores） of individual deposits. The assemblage includes magnetite, apatite and actinolite （or diopside）. The second type occurs within magnetite-apatite veins in the iron ores. The third type is seen in magnetite-apatite veins and （or） nodules in host rocks （i.e. gabbro-diorite porphyry or gabbro-diorite or pyroxene diorite）.The fourth type occurs within apatite-pyrite-quartz veins f＇dfing fractures in the Xiangshan Group. Rare earth elements （REE） geochemistry of apatite of the four occurrences in porphyry iron deposits is presented. The REE distribution patterns of apatite are generally similar to those of apatites in the Kiruna-type iron ores, nelsonites. They are enriched in fight REE, with pronounced negative Eu anomalies. The similarity of REE distribution patterns in apatites from various deposits in different locations in the world indicates a common process of formation for various ore types, e.g. immiscibility. Early magmatic apatites contain 3031.48-12080 ×10^-6 REE. Later hydrothermal apatite contains 1958 ×10^-6 REE, indicating that the later hydrothermal ore-forming solution contains lower REE. Although gabbro-diorite porphyry and apatite show similar REE patterns, gabbro-diorite porphyries have no europium anomalies or feeble positive or feeble negative europium anomalies, caused both by reduction environment of mantle source region and by fractionation and crystallization （immiscibility） under a high oxygen fugacity condition. Negative Eu anomalies of apatites were formed possibly due to acquisition of Eu^2＋ by earlier diopsite during ore magma cooling. The apatites in the Aoshan and Taishan iron deposits yield a narrow variation range of ^87Sr/^86Sr values from 0.7071 to 0.7073, similar to those of the volcanic and subvolcaulc rocks, indicating that apatites were formed by liquid immiscibility and differentiation
基金National Natural Science Foundation of China,No.41871350Scientific and Technological Basic Resources Survey Project,No.2017FY100900。
文摘The Qinling Mountains is not only the geographical boundary between North and South China,but also the boundary between subtropical and warm temperate zones.It plays an important role in the geo-ecological pattern of China.However,there is controversy about the specific location of this geographical boundary in academic community due to the complexity,transition and heterogeneity of the transitional zone,as well as the differences in the delimitation indicators and research purposes.To further reveal the characteristics of the North-South transitional zone and clarify the specific location of the geo-ecological boundary between North and South China,combined with SRTM topographic data,temperature and precipitation data,Pinus massoniana forest and Pinus tabulaeformis forest,which represent subtropical coniferous forest in South China and temperate coniferous forest in North China respectively,were chosen to analyze their spatial distributions in the Qinling-Daba Mountains and the climatic conditions at their boundary with the climatic indexes of annual precipitation,the coldest month(January) average temperature,the warmest month(July) average temperature and the annual average temperature.The results show that:(1) Pinus massoniana and Pinus tabulaeformis forests and the climate indicators of their boundary can be used as one of the vegetation-climate indexes for the delimitation of subtropical and warm temperate zones.The boundary between the subtropical coniferous forest(Pinus massoniana forest) and temperate coniferous forest(Pinus tabulaeformis forest) is located along the south slope of Funiu Mountain to the north edge of Hanzhong Basin(the south slope of Qinling Mountains) at an altitude of 1000–1200 m,where the climatic indictors are stable:the annual precipitation is about 750–1000 mm,the annual average temperature is about 12–14℃,the coldest monthly average temperature is 0–4℃,and the warmest monthly average temperature is about 22–26℃.(2) It can be more scientifically to delimitate the bo
基金Chinese National Program on Key Basic Research Project(Grant Nos.2017YFA0103300,2015CB964800)the National Science Foundation of China(Grant Nos.81622019,81502385,31570813 and 81601212)the Fundamental Research Funds for the Central Un iversities.
文摘Dear Editor,Over a half-century ago,Dr.Leonard Hayflick described the phenotype of a finite lifespan for human fibroblasts being passaged in in vitro cell culture(Hayflick et al.,1961),a phenomenon today known as replicative cellular senescence.Cellular senescence has been defined as a state in which cells lose their potential to divide and are permanently arrested in either the G1,or arguably the G2 stage of the cell cycle(Mao et al.,2012).In addition to replicative cellular senescenee—which is induced by large amounts of DNA damage at telomeres due to loss of the specialized T-loop structure—xogenous sublethal stresses such as ionizing radiati on,genotoxic chemicals or hyper-activated on cogenes may also trigger a similar form of senescence,stress induced premature cellular senescenee(SIPS).
文摘Focusing on the reform initiatives of Chinese Academy of Medical Sciences(CAMS) & Peking Union Medical College(PUMC) in medical scientific and technological innovation from perspectives of deepening the reform and optimizing the ecosystem of science and technology innovation,this article summarizes the highlights of CAMS & PUMC’s efforts in safeguarding people’ s health and promoting the Healthy China 2030 strategy through scientific and technological innovation in the fields including basic research,disease prevention and treatment,and medical technology in the past ten years.These achievements embody the endeavors and responsibility of CAMS& PUMC in realizing self-reliance and self-improvement of Chinese medical science and technology and highlight its contributions to the development of medical science and technology of China.
基金the National Natural Science Foundation of China(31701863)the University of South Carolina Office of Research(ASPIRE-I TrackllB,13010E244)the Postdoctoral Workstation of Jiangsu Academy of Agricultural Sciences.
文摘Plant immunity is controlled by both positive regulators such as PBS3 and EDS1 and negative regulators such as NPR3 and NPR4.However,the relationships among these important immune regulators remain elusive.In this study,we found that PBS3 interacts with EDS1 in both the cytoplasm and the nucleus,and is required for EDS1 protein accumulation?NPR3 and NPR4,which function as salicylic acid receptors and adaptors of Cullin3-based E3 ligase,interact with and mediate the degradation of EDS1 via the 26S proteasome.We further discovered that PBS3 inhibits the polyubiquitination and subsequent degradation of EDS1 by reducing the association of EDS1 with the Cullin3 adaptors NPR3 and NPR4.Furthermore,we showed that PBS3 and EDS1 also contribute to PAMP-triggered immunity in addition to effector-triggered immunity.Collectively,our study reveals a novel mechanism by which plants fine-tune defense resporises by inhibiting the degradation of a positive player in plant immunity.
基金This project(No.2010B090400067) was financially supported by the Foshan Science and Technology Bureauthe Education Department of Guangdong Province, China
文摘The influences of a 0.2 T static magnetic field on the microstructure of 7075 aluminum alloys sheets produced with a twin-roll continuous caster at 675℃ were investigated in this paper. Under a uniform magnetic field, the primary dendrites were refined and tended to be equiaxed. The microstructure consisted of an intermediate case between dendritic and equiaxed grains. Moreover, the use of an external static field in the twin-roll casting process can reduce heat discharge, resulting in a decrease in undercooling, and may also account for the abatement of segregation bands. In addition, the static magnetic field effectively improved the solute mixing capacity, and the added atoms more easily diffused from precipitates to theα-Al matrix, which resulted in an increase in the mechanical properties of the rolled sheets. Specimens prepared both in the presence of a static magnetic field and in the absence of a static magnetic field exhibited brittle-fracture characteristics.
文摘A computer simulation model of salt pan is presented.The transient behavior and the effects of various parameters of the salt pans,such as the depth of the brine layer,the absorptance of the soil surface,the thermal properties of the soil beneath the brine layer and the depth of the underground water table,on the evaporation process of salt pans are discussed.The effects of extra insulation layer and the intensity of solar radiation are also examined.
文摘Dear Editor,L-Fucose(6-deoxy-L-galactose,fucose)is the basic compone nt of a variety of glyca n structures.The fucosylated oligosaccharides participate in a variety of cellular activities,like the cell-cell recognition,selectin-mediated leukocyteendothelial adhesion and the formation of Lewis blood group antigens(Ma et al.,2006).GDP-fucose is an important fucose donor in the process of fucosylated oligosaccharides formation.Two pathways of GDP-fucose synthesis are present in the cytosol of mammalian cells,including the de novo pathway and the salvage pathway(Becker et al.,2003).In the salvage pathway,cells use fucose from the extracellular or lysosomal sources to synthesize GDP-fucose.
基金supported by the National Natural Science Foundation of China under Grant Nos.40175019 and 40275018the Key Project of the Ministry of Science and Technology of China under Grant No.2001DIA20026.
文摘There has been much progress in the study of tropical cyclones and tropical meteorology in China in the past few years. A new atmospheric field experiment of tropical cyclone landfall with the acronym of CLATEX (China Landfalling Typhoon Experiment) was implemented in July-August 2002. The boundary layer characteristics of the target typhoon Vongfong and the mesoscale structural features of other land-falling typhoons were studied. In addition, typhoon track operational forecasting errors in the last decade have been reduced because the operational monitoring equipment and forecast techniques were improved. Some results from the research program on tropical cvclone landfall, structure and intensity change, inten-sification near coastal waters, interaction between tropical cyclone and mid-latitude circulation, and the interaction among different scales of motion are described in this paper. Four major meteorological scien-tific experiments in China with international cooperation were implemented in 1998: the South China Sea monsoon field experiment (SCSMEX), the Tibetan Plateau field experiment (TIPEX), the Huaihe River basin energy and water cycle experiment (HUBEX), and the South China heavy rain scientific experiment (HUAMEX). Although these field experiments have different scientific objectives, they commonly relate to monsoon activities and they interact with each other. The valuable intensive observation data that were obtained have already been shared internationally. Some new findings have been published recently. Other research work in China, such as the tropical air-sea interaction, tropical atmospheric circulation, and weather systems, are reviewed in this paper as well. Some research results have shown that the rainfall anomalies for different regions in China were closely related to the stages of El Nino events.
文摘Orobanche spp. （broomrapes） are holoparasitic plants distributed predominantly in the Northern Hemisphere parasitizing the roots of a range of plant species mainly in wild ecosystems. Orobanche species cause severe yield reduction of many important crops. There are only very few herbicides which are able to selectively control broomrapes and different approaches have been put forward to develop natural product based pesticides to control Orobanche. Several phytopathogenic fungi were evaluated for their use as potential mycoherbicide and for ability to produce toxic metabolites which could be applied as herbicides. Using the alternative approach ＂suicidal germination＂, interesting results were obtained by testing two microbial metabolites （fusicoccins and ophiobolin A） especially with Orobanche species whose germination is not induced by the synthetic strigolactone GR24. From pea root exudates, peagol and peagoldione, close related to strigolactones, and three polyphenols, named peapolyphenols A-C, together with already well known polyphenol and a chalcone, were isolated. They showed a selective stimulation of Orobanche seed germination with the last two and peapolyphenol A showing a specific stimulatory activity on O. foetida. This review describes the most recent results achieved on Orobanche bio-control, mainly focusing on those regarding O. ramosa, O. crenata and O. foetida.
文摘Ataxia with oculomotor apraxia type 1 (AOA1) is an autosomal recessive disorde r characterized by earlyonset cerebellar ataxia, oculomotor apraxia, and perip heral neuropathy. The causative gene (APTX) has been recently identified in Port uguese and Japanese kindreds. Three patients with AOA1 were identified in an APT X mutation screening on 28 Southern Italian patients with progressive ataxia and peripheral neuropathy. A novel homozygous missense mutation (H201Q) was found i n one patient and a Japanese missense mutation (P206L) in two. AOA1 clinical het erogeneity and onset later than previously described are shown.
