Herein we review the current state-of-the-art of plant hydraulics in the context of plant physiology, ecology, and evolution, focusing on current and future research opportunities. We explain the physics of water tran...Herein we review the current state-of-the-art of plant hydraulics in the context of plant physiology, ecology, and evolution, focusing on current and future research opportunities. We explain the physics of water transport in plants and the limits of this transport system, highlighting the relationships between xylem structure and function. We describe the great variety of techniques existing for evaluating xylem resistance to cavitation. We address several methodological issues and their connec- tion with current debates on conduit refilling and exponentially shaped vulnerability curves. We analyze the trade-offs existing between water transport safety and efficiency. We also stress how little information is available on molecular biology of cavitation and the potential role of aquaporins in conduit refilling. Finally, we draw attention to how plant hydraulic traits can be used for modeling stomatal responses to environmental variables and climate change, including drought mortality.展开更多
Subgroup J Avian leucosis virus (ALV-J) strain NX0101 was inoculated into chicken embryo fibroblasts (CEF) monolayers in 6-well plates. The six wells of CEF inoculated with NX0101 were divided into groups A (without a...Subgroup J Avian leucosis virus (ALV-J) strain NX0101 was inoculated into chicken embryo fibroblasts (CEF) monolayers in 6-well plates. The six wells of CEF inoculated with NX0101 were divided into groups A (without anti-ALV-J serum in the medium); B (with anti-ALV-J serum in the medium), then viruses from each well of both groups were separately passed in CEF every 6 d; formed their independent passage lineages. For each lineage of both groups, gp85 genes of the viruses in the 10th, 20th; 30th passages were amplified, cloned; sequenced. The sequence data indicated that the homologies of gp85 at aa level between the primary virus; the passed viruses of different passages of 3 lineages in group A were 97.7%–99.7%;; the homologies of gp85 between the primary virus; the passed viruses of different passages of 3 lineages in group B were 93.8%–96.1%. Analysis of the ratios of nonsynonium (NS) vs synonium (S) mutations of nucleic acids demonstrated that NS/S in 3 highly variable (hr-) regions at aa#110–120, aa#141–151; aa#189–194 of gp85 in 3 lineages of group A were 2 (8/4), 1(3/3); 1.3 (4/3), however, NS/S in the same 3 hr-regions of group B were 4.1 (13/3), 4.7 (14/3); 3.3 (11/3). This study is the first demonstration of influence of immune selective pressure on evolution of ALV-J gp85 by specific antibodies under the controlled in vitro experiments.展开更多
AIM: To compare the short-term outcomes of patients who underwent proximal gastrectomy with jejunal interposition (PGJI) with those undergoing total gastrectomy with Roux-en-Y anastomosis (TGRY).
During daylight, plants produce excess photo- synthates, including sucrose, which is temporarily stored in the vacuole. At night, plants remobilize sucrose to sustain metabolism and growth. Based on homology to other ...During daylight, plants produce excess photo- synthates, including sucrose, which is temporarily stored in the vacuole. At night, plants remobilize sucrose to sustain metabolism and growth. Based on homology to other sucrose transporter （SUT） proteins, we hypothesized the maize （Zea mays） SUCROSE TRANSPORTER2 （ZmSUT2） protein functions as a sucrose/H^＋ symporter on the vacuolar membrane to export transiently stored sucrose. To understand the biological role of ZmSut2, we examined its spatial and temporal gene expression, determined the protein subcellular localization, and characterized loss-of- function mutations. ZmSut2 mRNA was ubiquitously expressed and exhibited diurnal cycling in transcript abundance. Expressing a translational fusion of ZmSUT2 fused to a red fluorescent protein in maize mesophyll cell protoplasts revealed that the protein localized to the tonoplast. Under field conditions, zmsut2 mutant plants grew slower, possessed smaller tassels and ears, and produced fewer kernels when compared to wild-type siblings, zmsut2 mutants also accumulated two-fold more sucrose, glucose, and fructose as well as starch in source leaves compared to wild type. These findings suggest （i） ZmSUT2 functions to remobilize sucrose out of the vacuole for subsequent use in growing tissues; and （ii） its function provides an important contribution to maize development and agronomic yield.展开更多
经过多次调整,计划将于2018年发射的詹姆斯·韦伯太空望远镜(James Webb Space Telescope,简称JWST)中的中红外仪(Mid-Infrared Instrument,简称MIRI)低温制冷系统最终选用三级脉管制冷机预冷J-T(Joule-Thomson)循环的复合型低温制...经过多次调整,计划将于2018年发射的詹姆斯·韦伯太空望远镜(James Webb Space Telescope,简称JWST)中的中红外仪(Mid-Infrared Instrument,简称MIRI)低温制冷系统最终选用三级脉管制冷机预冷J-T(Joule-Thomson)循环的复合型低温制冷技术。详细介绍了该技术的发展历程,表明该复合型低温制冷技术已在空间任务中逐渐替代固氢或液氦杜瓦技术,以期为国家未来空间计划的实施提供借鉴。展开更多
AIM： To search for new antiviral agents from traditional Chinese medicine, specifically anti-enterovirosuses agents. METHODS： The aqueous extracts （AE） of more than 100 traditionally used medicinal plants in China...AIM： To search for new antiviral agents from traditional Chinese medicine, specifically anti-enterovirosuses agents. METHODS： The aqueous extracts （AE） of more than 100 traditionally used medicinal plants in China were evaluated for their in vitro anti-Coxsackie virus B3 activities with a MTT-based colorimetric assay. RESULTS： The test for AE of 16 plants exhibited anti- Coxsackie virus B3 activities at different magnitudes of potency. They can inhibit three steps （inactivation, adsorption and replication） during the infection. Among the 16 plants, Sargentodoxa cuneata （Oliv.） Rehd. et Wils., Sophora tonkinensis Gapnep., Paeonia veitchii Lynch, Spatholobus suberectus Dunn. and Cyrtorniurn fortunei J, sm. also have activity against other enterovirus, including Coxsackie virus 135, Polio virus I, Echo virus 9 and Echo virus 29. Cell cytotoxic assay demonstrated that all tested AE had CC50 values higher than their EC50 values. CONCLUSION： The sixteen traditionally used medicinal plants in China possessed antMral activity, and some of them merit further investigations.展开更多
基金provided by National Science Foundation grant IOS-1450560
文摘Herein we review the current state-of-the-art of plant hydraulics in the context of plant physiology, ecology, and evolution, focusing on current and future research opportunities. We explain the physics of water transport in plants and the limits of this transport system, highlighting the relationships between xylem structure and function. We describe the great variety of techniques existing for evaluating xylem resistance to cavitation. We address several methodological issues and their connec- tion with current debates on conduit refilling and exponentially shaped vulnerability curves. We analyze the trade-offs existing between water transport safety and efficiency. We also stress how little information is available on molecular biology of cavitation and the potential role of aquaporins in conduit refilling. Finally, we draw attention to how plant hydraulic traits can be used for modeling stomatal responses to environmental variables and climate change, including drought mortality.
文摘Subgroup J Avian leucosis virus (ALV-J) strain NX0101 was inoculated into chicken embryo fibroblasts (CEF) monolayers in 6-well plates. The six wells of CEF inoculated with NX0101 were divided into groups A (without anti-ALV-J serum in the medium); B (with anti-ALV-J serum in the medium), then viruses from each well of both groups were separately passed in CEF every 6 d; formed their independent passage lineages. For each lineage of both groups, gp85 genes of the viruses in the 10th, 20th; 30th passages were amplified, cloned; sequenced. The sequence data indicated that the homologies of gp85 at aa level between the primary virus; the passed viruses of different passages of 3 lineages in group A were 97.7%–99.7%;; the homologies of gp85 between the primary virus; the passed viruses of different passages of 3 lineages in group B were 93.8%–96.1%. Analysis of the ratios of nonsynonium (NS) vs synonium (S) mutations of nucleic acids demonstrated that NS/S in 3 highly variable (hr-) regions at aa#110–120, aa#141–151; aa#189–194 of gp85 in 3 lineages of group A were 2 (8/4), 1(3/3); 1.3 (4/3), however, NS/S in the same 3 hr-regions of group B were 4.1 (13/3), 4.7 (14/3); 3.3 (11/3). This study is the first demonstration of influence of immune selective pressure on evolution of ALV-J gp85 by specific antibodies under the controlled in vitro experiments.
文摘AIM: To compare the short-term outcomes of patients who underwent proximal gastrectomy with jejunal interposition (PGJI) with those undergoing total gastrectomy with Roux-en-Y anastomosis (TGRY).
基金supported by the National Science Foundation Plant Genome Research Program, grant no. IOS-1025976 to DMB
文摘During daylight, plants produce excess photo- synthates, including sucrose, which is temporarily stored in the vacuole. At night, plants remobilize sucrose to sustain metabolism and growth. Based on homology to other sucrose transporter （SUT） proteins, we hypothesized the maize （Zea mays） SUCROSE TRANSPORTER2 （ZmSUT2） protein functions as a sucrose/H^＋ symporter on the vacuolar membrane to export transiently stored sucrose. To understand the biological role of ZmSut2, we examined its spatial and temporal gene expression, determined the protein subcellular localization, and characterized loss-of- function mutations. ZmSut2 mRNA was ubiquitously expressed and exhibited diurnal cycling in transcript abundance. Expressing a translational fusion of ZmSUT2 fused to a red fluorescent protein in maize mesophyll cell protoplasts revealed that the protein localized to the tonoplast. Under field conditions, zmsut2 mutant plants grew slower, possessed smaller tassels and ears, and produced fewer kernels when compared to wild-type siblings, zmsut2 mutants also accumulated two-fold more sucrose, glucose, and fructose as well as starch in source leaves compared to wild type. These findings suggest （i） ZmSUT2 functions to remobilize sucrose out of the vacuole for subsequent use in growing tissues; and （ii） its function provides an important contribution to maize development and agronomic yield.
文摘经过多次调整,计划将于2018年发射的詹姆斯·韦伯太空望远镜(James Webb Space Telescope,简称JWST)中的中红外仪(Mid-Infrared Instrument,简称MIRI)低温制冷系统最终选用三级脉管制冷机预冷J-T(Joule-Thomson)循环的复合型低温制冷技术。详细介绍了该技术的发展历程,表明该复合型低温制冷技术已在空间任务中逐渐替代固氢或液氦杜瓦技术,以期为国家未来空间计划的实施提供借鉴。
文摘AIM： To search for new antiviral agents from traditional Chinese medicine, specifically anti-enterovirosuses agents. METHODS： The aqueous extracts （AE） of more than 100 traditionally used medicinal plants in China were evaluated for their in vitro anti-Coxsackie virus B3 activities with a MTT-based colorimetric assay. RESULTS： The test for AE of 16 plants exhibited anti- Coxsackie virus B3 activities at different magnitudes of potency. They can inhibit three steps （inactivation, adsorption and replication） during the infection. Among the 16 plants, Sargentodoxa cuneata （Oliv.） Rehd. et Wils., Sophora tonkinensis Gapnep., Paeonia veitchii Lynch, Spatholobus suberectus Dunn. and Cyrtorniurn fortunei J, sm. also have activity against other enterovirus, including Coxsackie virus 135, Polio virus I, Echo virus 9 and Echo virus 29. Cell cytotoxic assay demonstrated that all tested AE had CC50 values higher than their EC50 values. CONCLUSION： The sixteen traditionally used medicinal plants in China possessed antMral activity, and some of them merit further investigations.
