Endosymbiosis with Gammaproteobacteria is fundamental for the success of bathymodioline mussels in deep-sea chemosynthesis-based ecosystems. However, the recent discovery of Campylobacteria on the gill surfaces of the...Endosymbiosis with Gammaproteobacteria is fundamental for the success of bathymodioline mussels in deep-sea chemosynthesis-based ecosystems. However, the recent discovery of Campylobacteria on the gill surfaces of these mussels suggests that these host-bacterial relationships may be more complex than previously thought. Using the cold-seep mussel(Gigantidas haimaensis) as a model, we explored this hostbacterial system by assembling the host transcriptome and genomes of its epibiotic Campylobacteria and endosymbiotic Gammaproteobacteria and quantifying their gene and protein expression levels. We found that the epibiont applies a sulfur oxidizing(SOX)multienzyme complex with the acquisition of sox B from Gammaproteobacteria for energy production and switched from a reductive tricarboxylic acid (rTCA) cycle to a Calvin-Benson-Bassham(CBB)cycle for carbon assimilation. The host provides metabolic intermediates, inorganic carbon, and thiosulfate to satisfy the materials and energy requirements of the epibiont, but whether the epibiont benefits the host is unclear. The endosymbiont adopts methane oxidation and the ribulose monophosphate pathway(Ru MP) for energy production, providing the major source of energy for itself and the host. The host obtains most of its nutrients, such as lysine, glutamine, valine,isoleucine, leucine, histidine, and folate, from the endosymbiont. In addition, host pattern recognition receptors, including toll-like receptors, peptidoglycan recognition proteins, and C-type lectins, may participate in bacterial infection, maintenance, and population regulation. Overall, this study provides insights into the complex host-bacterial relationships that have enabled mussels and bacteria to thrive in deep-sea chemosynthetic ecosystems.展开更多
In order to find novel synthetic antitumor agents with superior cytotoxicity and overcoming multidrug resistance, a novel series of 4β-N-substituted podophyllotoxin derivatives were synthesized and evaluated as poten...In order to find novel synthetic antitumor agents with superior cytotoxicity and overcoming multidrug resistance, a novel series of 4β-N-substituted podophyllotoxin derivatives were synthesized and evaluated as potential antitumor agents. Seven novel podophyllotoxin derivatives were synthesized by linking 4β-amino-4-deoxypodophyllotoxin with N-substituted 5-methylindol-3- yl-glyoxyl chlorides and tested against K562 and K562/A02 using SRB methods in vitro, KB and KBVusing MTT methods in vitro.展开更多
Pure Al2O3-2SiO2 powders were prepared by sol-gel and coprecipitation methods, and their alkaliactivation reactivities were compared. The alkali-activation reactivity of the powder prepared by the so]-gel method was h...Pure Al2O3-2SiO2 powders were prepared by sol-gel and coprecipitation methods, and their alkaliactivation reactivities were compared. The alkali-activation reactivity of the powder prepared by the so]-gel method was higher than that of the powder prepared by the coprecipitation method. The powders were investigated by 27Al and 29Si magic-angle spinning nuclear magnetic resonance spectroscopy (MAS NMR) to understand the relationship between their structure and alkali-activation reactivity. The 27Al MAS NMR data showed that the five-coordinate AI content of the powder prepared by the sol-gel method was higher than that of the powder prepared by coprecipitation. The higher content of five-coordinate Al corresponded to higher alkali-activation reactivity. The 29Si MAS NMR data showed that for the powder prepared by the sol-gel method, silicon was replaced by aluminum at secondary coordination sites of the central Si atoms during calcination. However, for the powder prepared by single-batch coprecipitation, the main change was from a low degree of polycondensation to a high degree of polycondensation.展开更多
基金supported by the Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)(GML2019ZD0409,SMSEGL20SC02)Research Grants Council of Hong Kong(12101021)Guangdong Natural Science Foundation(2020A1515011117)。
文摘Endosymbiosis with Gammaproteobacteria is fundamental for the success of bathymodioline mussels in deep-sea chemosynthesis-based ecosystems. However, the recent discovery of Campylobacteria on the gill surfaces of these mussels suggests that these host-bacterial relationships may be more complex than previously thought. Using the cold-seep mussel(Gigantidas haimaensis) as a model, we explored this hostbacterial system by assembling the host transcriptome and genomes of its epibiotic Campylobacteria and endosymbiotic Gammaproteobacteria and quantifying their gene and protein expression levels. We found that the epibiont applies a sulfur oxidizing(SOX)multienzyme complex with the acquisition of sox B from Gammaproteobacteria for energy production and switched from a reductive tricarboxylic acid (rTCA) cycle to a Calvin-Benson-Bassham(CBB)cycle for carbon assimilation. The host provides metabolic intermediates, inorganic carbon, and thiosulfate to satisfy the materials and energy requirements of the epibiont, but whether the epibiont benefits the host is unclear. The endosymbiont adopts methane oxidation and the ribulose monophosphate pathway(Ru MP) for energy production, providing the major source of energy for itself and the host. The host obtains most of its nutrients, such as lysine, glutamine, valine,isoleucine, leucine, histidine, and folate, from the endosymbiont. In addition, host pattern recognition receptors, including toll-like receptors, peptidoglycan recognition proteins, and C-type lectins, may participate in bacterial infection, maintenance, and population regulation. Overall, this study provides insights into the complex host-bacterial relationships that have enabled mussels and bacteria to thrive in deep-sea chemosynthetic ecosystems.
基金supported by the National Natural Science Foundation of China(No.30873363)the Great Program of Science Foundation of Tianjin(No.09ZCKFNC01200)Program of Science Foundation of Tianjin (No.08JCYBJC070000).
文摘In order to find novel synthetic antitumor agents with superior cytotoxicity and overcoming multidrug resistance, a novel series of 4β-N-substituted podophyllotoxin derivatives were synthesized and evaluated as potential antitumor agents. Seven novel podophyllotoxin derivatives were synthesized by linking 4β-amino-4-deoxypodophyllotoxin with N-substituted 5-methylindol-3- yl-glyoxyl chlorides and tested against K562 and K562/A02 using SRB methods in vitro, KB and KBVusing MTT methods in vitro.
基金supported by the Chinese Natural Science Fund (Grant Nos.51262002 and 50962002)Guangxi Experiment Center of Science and Technology(Grant No.LGZXKF201202)+2 种基金Guangxi Natural Science Fund(Grant No.2014GXNSFAA118323)Research Project of the Education Department of Guangxi Government (Grant No.201204LX238)Opening Fund of Doctor Station Construction of Guangxi Teachers Education University
文摘Pure Al2O3-2SiO2 powders were prepared by sol-gel and coprecipitation methods, and their alkaliactivation reactivities were compared. The alkali-activation reactivity of the powder prepared by the so]-gel method was higher than that of the powder prepared by the coprecipitation method. The powders were investigated by 27Al and 29Si magic-angle spinning nuclear magnetic resonance spectroscopy (MAS NMR) to understand the relationship between their structure and alkali-activation reactivity. The 27Al MAS NMR data showed that the five-coordinate AI content of the powder prepared by the sol-gel method was higher than that of the powder prepared by coprecipitation. The higher content of five-coordinate Al corresponded to higher alkali-activation reactivity. The 29Si MAS NMR data showed that for the powder prepared by the sol-gel method, silicon was replaced by aluminum at secondary coordination sites of the central Si atoms during calcination. However, for the powder prepared by single-batch coprecipitation, the main change was from a low degree of polycondensation to a high degree of polycondensation.