Potentiodynamic polarization tests and slow strain rate test（SSRT） in combination with fracture morphology observations were conducted to investigate the stress corrosion cracking（SCC） behavior of 7003 aluminum al...Potentiodynamic polarization tests and slow strain rate test（SSRT） in combination with fracture morphology observations were conducted to investigate the stress corrosion cracking（SCC） behavior of 7003 aluminum alloy（AA7003） in acid and alkaline chloride solutions under various applied potentials（Ea）. The results show that AA7003 is to a certain extent susceptible to SCC via anodic dissolution（AD） at open-circuit potential（OCP） and is highly susceptible to hydrogen embrittlement（HE） at high negative Ea in the solutions with p H levels of 4 and 11. The susceptibility increases with negative shift in the potential when Ea is less than-1000 m V vs. SCE. However, the susceptibility distinctly decreases because of the inhibition of AD when Ea is equal to-1000 m V vs. SCE. In addition, the SCC susceptibility of AA7003 in the acid chloride solution is higher than that in the alkaline solution at each potential. Moreover, the effect of hydrogen on SCC increases with increasing hydrogen ion concentration.展开更多
The phenylpropanoid enzyme 4-coumarate： coenzyme A ligase （4CL）, plays a key role in general phenylpropanoid metabolism. Our investigation involves a new 4CL-like gene cloned from Populus tomentosa. This new 4CL- l...The phenylpropanoid enzyme 4-coumarate： coenzyme A ligase （4CL）, plays a key role in general phenylpropanoid metabolism. Our investigation involves a new 4CL-like gene cloned from Populus tomentosa. This new 4CL- like gene is 1,692 bp and encodes a protein of 552 aa. After analysis of its domain, we found a highly conserved region of a 4CL gene family in this 4CL-like gene. Based on our results, we believe that this gene belongs to the family of 4CL. A recombinant vector, referred to as pET30a-4CL-like, was constructed by connecting this 4CL-like gene fragment to pET30a. After inducing it with IPTG for 3 h, the 4CL-like protein was purified by a Ni-NTA method. This 4CL-like protein has a calculated molecular weight of 60 kDa by SDS-PAGE.展开更多
AIM: To assess surgical outcomes of a novel method of transscleral drainage of subretinal fluid using a 25-gauge trocar-cannula with a self-closing valve(DTV) in patients with severe exudative retinal detachment(ERD) ...AIM: To assess surgical outcomes of a novel method of transscleral drainage of subretinal fluid using a 25-gauge trocar-cannula with a self-closing valve(DTV) in patients with severe exudative retinal detachment(ERD) in Coats disease.METHODS: Retrospective consecutive cases of 20 patients(20 eyes) of severe ERD due to Coats disease(stage 3 B) in total 156 Coats patients between June 2015 and April 2019 were included in this study. The participants were aged 1 to 10 y with a mean age of 3.50±1.79 y. The mean follow-up time were 11.9 mo. Subretinal fluid was drained transsclerally using a novel method of DTV. The height of the retinal detachment and the regression of abnormal vessels including telangiectasias and aneurysms were observed. Complications including vitreoretinal fibrosis, tractional retinal detachments(TRD), endophthalmitis, retinal holes, and hemorrhages were evaluated.RESULTS: Following surgeries, the patients showed the replacement of ERD and regression of telangiectatic retinal vessels observed with binocular indirect ophthalmoscopy. Six patients received retinal cryotherapies and 12 patients received laser photocoagulations following first external subretinal fluid drainage using DTV. All patients underwent intravitreal anti-vascular endothelial growth factor therapies to induce residual subretinal fluid absorption. During followups, 8 patients underwent a second drainage operation, 17 patients received retinal laser photocoagulations and 7 patients received cryotherapies. Vitreoretinal fibrosis was found in 7 patients and 6 patients underwent microinvasive vitrectomies during the follow-up period. Severe TRD, iatrogenic retinal holes, and hemorrhages were not found.CONCLUSION: The authors present a new therapeutic approach that successfully drains subretinal fluid in advanced stage 3 B Coats disease with severe ERD. This is a simple, safe and less invasive approach when compared with traditional managements. However, it should be strictly selected for patients with high bullous ERD close to the central axis of the eye in order to avoid the complication of retinal holes.展开更多
Confocal Raman microspectroscopy(CRM)is an important tool for analyzing the compositional distribution of cell walls in situ.In this study,we improved the sample preparation method using paraffin-embedded sections com...Confocal Raman microspectroscopy(CRM)is an important tool for analyzing the compositional distribution of cell walls in situ.In this study,we improved the sample preparation method using paraffin-embedded sections combined with hexane dewaxing to obtain high resolution Raman images.We determined that the cell wall components of fiber cells were different from those of ray cells and vessel cells in the xylem of Populus tomentosa.Acetyl bromide and CRM methods produced similar trends when the difference in lignin intensity in the xylem region was compared between transgenic PtrLac4 and wild-type P.tomentosa.However,CRM proved more useful to analyze the lignin distribution in each cell type and distinguished the detailed difference in lignin intensity at the cellular level.Thus,CRM proved to be a useful in situ method to rapidly analyze the spatial variation of lignin content in the xylem of woody plants.展开更多
The tetrazolium salt 2-( 4-Iodophenyl)-3-( 4-nitrophenyl)-5-phenyltetrazolium chloride( INT) was used as a tool for estimating the activity of the electron transport system( ETS) in activated sludge in a 40 L sequenci...The tetrazolium salt 2-( 4-Iodophenyl)-3-( 4-nitrophenyl)-5-phenyltetrazolium chloride( INT) was used as a tool for estimating the activity of the electron transport system( ETS) in activated sludge in a 40 L sequencing batch reactor( SBR) and domestic sewage as the organic substrate. The activity of INT-ETS during one SBR cycle,and the effect of the ammonia concentration and the concentration of organic matter influent on the INT-ETS activity were investigated. The results show that: the use of INT is reliable in estimating of biological activity of activated sludge of SBR system; Biological activity of organic matter biodegradation, nitrification and denitrification process in SBR system reduce orderly. Obviously,INT-ETS activity reduces from 232. 59 mg /( g·h) to 190. 65 mg /( g·h) at first and then decreases to 113. 88 mg /( g·h) when influent concentration of COD and NH4 +-N is 300 mg / L and 40 mg / L respectively. In addition,various influent Nitrogen( NH4 +-N are 14. 5 mg / L and 42. 0 mg / L) and organic shock loading( COD are 293 mg / L and 685 mg / L) experimentations cure prove that operational conditions have no obvious effect on INT-ETS variation rule. However,the time of the appearance of feature points marking different reaction phase is influenced.展开更多
基金financially supported by the National Natural Science Foundation of China(No.51371039)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD),Jiangsu Province,China
文摘Potentiodynamic polarization tests and slow strain rate test（SSRT） in combination with fracture morphology observations were conducted to investigate the stress corrosion cracking（SCC） behavior of 7003 aluminum alloy（AA7003） in acid and alkaline chloride solutions under various applied potentials（Ea）. The results show that AA7003 is to a certain extent susceptible to SCC via anodic dissolution（AD） at open-circuit potential（OCP） and is highly susceptible to hydrogen embrittlement（HE） at high negative Ea in the solutions with p H levels of 4 and 11. The susceptibility increases with negative shift in the potential when Ea is less than-1000 m V vs. SCE. However, the susceptibility distinctly decreases because of the inhibition of AD when Ea is equal to-1000 m V vs. SCE. In addition, the SCC susceptibility of AA7003 in the acid chloride solution is higher than that in the alkaline solution at each potential. Moreover, the effect of hydrogen on SCC increases with increasing hydrogen ion concentration.
基金supported by the National Natural Science Foundation of China (Grant Nos.31170574 and 30671697)
文摘The phenylpropanoid enzyme 4-coumarate： coenzyme A ligase （4CL）, plays a key role in general phenylpropanoid metabolism. Our investigation involves a new 4CL-like gene cloned from Populus tomentosa. This new 4CL- like gene is 1,692 bp and encodes a protein of 552 aa. After analysis of its domain, we found a highly conserved region of a 4CL gene family in this 4CL-like gene. Based on our results, we believe that this gene belongs to the family of 4CL. A recombinant vector, referred to as pET30a-4CL-like, was constructed by connecting this 4CL-like gene fragment to pET30a. After inducing it with IPTG for 3 h, the 4CL-like protein was purified by a Ni-NTA method. This 4CL-like protein has a calculated molecular weight of 60 kDa by SDS-PAGE.
基金Supported by Beijing Tongren Hospital,Capital Medical University(No.TRZDYXZY201703)
文摘AIM: To assess surgical outcomes of a novel method of transscleral drainage of subretinal fluid using a 25-gauge trocar-cannula with a self-closing valve(DTV) in patients with severe exudative retinal detachment(ERD) in Coats disease.METHODS: Retrospective consecutive cases of 20 patients(20 eyes) of severe ERD due to Coats disease(stage 3 B) in total 156 Coats patients between June 2015 and April 2019 were included in this study. The participants were aged 1 to 10 y with a mean age of 3.50±1.79 y. The mean follow-up time were 11.9 mo. Subretinal fluid was drained transsclerally using a novel method of DTV. The height of the retinal detachment and the regression of abnormal vessels including telangiectasias and aneurysms were observed. Complications including vitreoretinal fibrosis, tractional retinal detachments(TRD), endophthalmitis, retinal holes, and hemorrhages were evaluated.RESULTS: Following surgeries, the patients showed the replacement of ERD and regression of telangiectatic retinal vessels observed with binocular indirect ophthalmoscopy. Six patients received retinal cryotherapies and 12 patients received laser photocoagulations following first external subretinal fluid drainage using DTV. All patients underwent intravitreal anti-vascular endothelial growth factor therapies to induce residual subretinal fluid absorption. During followups, 8 patients underwent a second drainage operation, 17 patients received retinal laser photocoagulations and 7 patients received cryotherapies. Vitreoretinal fibrosis was found in 7 patients and 6 patients underwent microinvasive vitrectomies during the follow-up period. Severe TRD, iatrogenic retinal holes, and hemorrhages were not found.CONCLUSION: The authors present a new therapeutic approach that successfully drains subretinal fluid in advanced stage 3 B Coats disease with severe ERD. This is a simple, safe and less invasive approach when compared with traditional managements. However, it should be strictly selected for patients with high bullous ERD close to the central axis of the eye in order to avoid the complication of retinal holes.
基金funded by the Fundamental Research Funds for the Central Universities(Grant No.2019ZY30)National Natural Science Foundation of China(Grant No.31971618,Grant No.31570582)。
文摘Confocal Raman microspectroscopy(CRM)is an important tool for analyzing the compositional distribution of cell walls in situ.In this study,we improved the sample preparation method using paraffin-embedded sections combined with hexane dewaxing to obtain high resolution Raman images.We determined that the cell wall components of fiber cells were different from those of ray cells and vessel cells in the xylem of Populus tomentosa.Acetyl bromide and CRM methods produced similar trends when the difference in lignin intensity in the xylem region was compared between transgenic PtrLac4 and wild-type P.tomentosa.However,CRM proved more useful to analyze the lignin distribution in each cell type and distinguished the detailed difference in lignin intensity at the cellular level.Thus,CRM proved to be a useful in situ method to rapidly analyze the spatial variation of lignin content in the xylem of woody plants.
基金Sponsored by the National Water Pollution Control and Management Technology Major Projects(Grant No.2012ZX07408001-07,2012ZX07201001-01)
文摘The tetrazolium salt 2-( 4-Iodophenyl)-3-( 4-nitrophenyl)-5-phenyltetrazolium chloride( INT) was used as a tool for estimating the activity of the electron transport system( ETS) in activated sludge in a 40 L sequencing batch reactor( SBR) and domestic sewage as the organic substrate. The activity of INT-ETS during one SBR cycle,and the effect of the ammonia concentration and the concentration of organic matter influent on the INT-ETS activity were investigated. The results show that: the use of INT is reliable in estimating of biological activity of activated sludge of SBR system; Biological activity of organic matter biodegradation, nitrification and denitrification process in SBR system reduce orderly. Obviously,INT-ETS activity reduces from 232. 59 mg /( g·h) to 190. 65 mg /( g·h) at first and then decreases to 113. 88 mg /( g·h) when influent concentration of COD and NH4 +-N is 300 mg / L and 40 mg / L respectively. In addition,various influent Nitrogen( NH4 +-N are 14. 5 mg / L and 42. 0 mg / L) and organic shock loading( COD are 293 mg / L and 685 mg / L) experimentations cure prove that operational conditions have no obvious effect on INT-ETS variation rule. However,the time of the appearance of feature points marking different reaction phase is influenced.
