Polyaspartic acid(PASP)is a nontoxic,biodegradable,environmentally friendly polymer and is widely used as a fertilizer synergist in agricultural production.In many old orchards and vegetable gardens,highly fertile soi...Polyaspartic acid(PASP)is a nontoxic,biodegradable,environmentally friendly polymer and is widely used as a fertilizer synergist in agricultural production.In many old orchards and vegetable gardens,highly fertile soil is often accompanied by severe heavy metal contamination.The present study was designed to investigate mineral element interactions mediated by PASP under copper(Cu)+cadmium(Cd)combined stress to provide reasonable suggestions for scientific fertilization.A pot experiment was conducted in which tomato seedlings served as plant materials.A concentration of 700 mgPASP and foliar spraying application methods were selected based on previous experiments.Four treatments were applied:normal soil(control(CK)),Cu+Cd(combined stress),Cu+Cd+PASP,and normal soil+PASP.The plant biomass,root activity,and mineral elements were measured,and these data were analyzed by Data Processing System(DPS)statistical software.The results showed that,under Cu+Cd combined stress,PASP promoted stem diameter growth,root activity and chlorophyll content and ultimately increased the biomass of tomato seedlings to different degrees.Moreover,the content of both Cu and Cd and their individual accumulation in plants decreased.PASP increased the distribution of Cu and Cd in the roots under Cu+Cd combined stress,and the translocation ability from the roots to shoots was significantly restricted.With respect to essential elements,PASP promoted mainly the absorption and translocation of potassium(K),calcium(Ca),and magnesium(Mg),which greatly exerted physiological roles.However,the variation trends of Cu and Cd under normal soil conditions contrasted with those under stress conditions.With respect to essential elements other than K,Ca,and Mg,PASP mostly restrained their absorption but promoted their translocation.The regulatory mechanism of PASP differed between the combined stress conditions and normal soil conditions.Under the combined stress conditions,PASP seemed to mainly promote these advantageous factors that exert physiological regulatory functions.Under normal soil conditions,PASP mainly acted as a biological stimulant or signaling molecule for increased nutrient efficiency,which caused greater biomass productivity.展开更多
AIM: To prepare chitosan-polyaspartic acid-5-fluorouracil (CTS-Pasp-5Fu) nanoparticles and investigate its anti-carcinoma effect and toxicity. METHODS: CTS-Pasp-5Fu nanoparticles were synthesized by ionic gelatificati...AIM: To prepare chitosan-polyaspartic acid-5-fluorouracil (CTS-Pasp-5Fu) nanoparticles and investigate its anti-carcinoma effect and toxicity. METHODS: CTS-Pasp-5Fu nanoparticles were synthesized by ionic gelatification. Male BABL/c nude mice were injected with SGC-7901 gastric carcinoma cell line mass to establish a human gastric carcinoma model. They were randomly allocated into 4 groups: CTS-Pasp-5Fu (containing 5-Fu 1.25 mg/kg), 5-Fu (1.25 mg/kg), CTS-Pasp and normal saline groups. Tumor weight was measured and assay of colony forming unit-granulocyte and macrophage (CFU-GM) was performed. The structural change of cells and tissues was observed and the Bax and Bcl-2 genes were detected. RESULTS: Compared with normal saline, the inhibition rates of tumor growth for the CTS-Pasp, 5-Fu and CTS-Pasp-5Fu groups were 5.58%, 58.69% and 70.82%, respectively. The tumor inhibition rates for the CTS-Pasp, 5-Fu and CTS-Pasp-5Fu groups were 5.09%, 65.3% and 72.79%, respectively. There was a significant decrease in the number of CFU-GMformation and increase of total bilirubin, and alanine aminotransferase in the 5-Fu group, but no change in those of the other three groups. There was no change in white blood cell count and creatinine among the four groups. Pathological section of liver and nephridial tissues showed that the damage in the 5-Fu group was more severe than that in the CTS-Pasp-5Fu group. 5-Fu and CTS-Pasp-5Fu groups could both down-regulate the Bcl-2 expression and up-regulate the Bax expression to different extent, and the accommodate effect of CTS-Pasp-5Fu was more obvious than 5-Fu. CONCLUSION: The tumor inhibition rate of CTS-Pasp-5Fu nanoparticles is much higher than that of 5-Fu alone.展开更多
Environmentally friendly flotation reagent,polyaspartic acid(PAPA),was tested as a potential selective depressant in the flotation separation of chalcopyrite and Cu-activated sphalerite.The depression mechanism of PAP...Environmentally friendly flotation reagent,polyaspartic acid(PAPA),was tested as a potential selective depressant in the flotation separation of chalcopyrite and Cu-activated sphalerite.The depression mechanism of PAPA was revealed by contact angle measurements,Zeta potential measurements,Fourier transform infrared spectroscopy(FT-IR)analysis and inductively coupled plasma(ICP)measurement.The micro-flotation tests with single minerals showed that PAPA selectively depressed Cu-activated sphalerite,while chalcopyrite remained floatable.Moreover,a concentrate containing 31.40%Cu with a recovery of 92.43%was obtained in flotation tests of artificially mixed minerals.Results of contact angle measurements,Zeta potential measurements and FT-IR spectrum revealed that PAPA exerted a much stronger adsorption on Cu-activated sphalerite surface than on chalcopyrite surface,preventing the further adsorption of sodium diethyl dithiocarbamate(DDTC)on its surface.ICP measurements indicated that PAPA had an excellent complexing ability with Cu^(2+)in flotation pulp,weakening the activation of Cu species on sphalerite surface and producing selective depression.展开更多
The inhibition behavior of polyaspartic acid(PASP)as an environment-friendly corrosion inhibitor for WE43 magnesium alloy was investigated in 3.5 wt.%NaCl solution by means for EIS measurement,potentiodynamic polariza...The inhibition behavior of polyaspartic acid(PASP)as an environment-friendly corrosion inhibitor for WE43 magnesium alloy was investigated in 3.5 wt.%NaCl solution by means for EIS measurement,potentiodynamic polarization curve,and scanning electron microscopy.The results show that PASP can inhibit the corrosion of WE43 magnesium alloy.The maximum inhibition efficiency is achieved when PASP concentration is 400 ppm in this study.展开更多
[Objective] This study was conducted to analyze the effects of humic acid and PASP on the growth of broccoli to provide a basis for fertilizer application.[Method] A field experiment was carried out to investigate bro...[Objective] This study was conducted to analyze the effects of humic acid and PASP on the growth of broccoli to provide a basis for fertilizer application.[Method] A field experiment was carried out to investigate broccoli growth, yield and quality by using humic acids and PASP as fertilizer synergists in the mixture with compound fertilizer. [Results] The treatment of 5‰ humic acid ＋ 3‰ PASP ＋ compound fertilizer exhibited the plant height, stem diameter and yield increased by8.3%, 13.3% and 10.3%, respectively, and thus was the best; and the treatment showed a single curd weight of 478 g and a commodity rate of 89.4%, and had lower economic cost than treatment of 10‰ humic acid ＋ 6‰ PASP ＋ compound fertilizer. [Conclusion] In summary, 5‰ humic acid ＋ 3‰ PASP ＋ compound fertilizer is suitable for wide application in broccoli culture.展开更多
基金supported by the Project of Shandong Province Higher Educational Science and Technology Program,China(J16LF02)the Funds of Shandong"Double Tops"Program,China(SYL2017YSTD01)the Major Scientific and Technological Innovation Project in Shandong Province,China(2018CXGC0209)
文摘Polyaspartic acid(PASP)is a nontoxic,biodegradable,environmentally friendly polymer and is widely used as a fertilizer synergist in agricultural production.In many old orchards and vegetable gardens,highly fertile soil is often accompanied by severe heavy metal contamination.The present study was designed to investigate mineral element interactions mediated by PASP under copper(Cu)+cadmium(Cd)combined stress to provide reasonable suggestions for scientific fertilization.A pot experiment was conducted in which tomato seedlings served as plant materials.A concentration of 700 mgPASP and foliar spraying application methods were selected based on previous experiments.Four treatments were applied:normal soil(control(CK)),Cu+Cd(combined stress),Cu+Cd+PASP,and normal soil+PASP.The plant biomass,root activity,and mineral elements were measured,and these data were analyzed by Data Processing System(DPS)statistical software.The results showed that,under Cu+Cd combined stress,PASP promoted stem diameter growth,root activity and chlorophyll content and ultimately increased the biomass of tomato seedlings to different degrees.Moreover,the content of both Cu and Cd and their individual accumulation in plants decreased.PASP increased the distribution of Cu and Cd in the roots under Cu+Cd combined stress,and the translocation ability from the roots to shoots was significantly restricted.With respect to essential elements,PASP promoted mainly the absorption and translocation of potassium(K),calcium(Ca),and magnesium(Mg),which greatly exerted physiological roles.However,the variation trends of Cu and Cd under normal soil conditions contrasted with those under stress conditions.With respect to essential elements other than K,Ca,and Mg,PASP mostly restrained their absorption but promoted their translocation.The regulatory mechanism of PASP differed between the combined stress conditions and normal soil conditions.Under the combined stress conditions,PASP seemed to mainly promote these advantageous factors that exert physiological regulatory functions.Under normal soil conditions,PASP mainly acted as a biological stimulant or signaling molecule for increased nutrient efficiency,which caused greater biomass productivity.
基金Shanghai Science and Technology Committee, No. 0452nm065
文摘AIM: To prepare chitosan-polyaspartic acid-5-fluorouracil (CTS-Pasp-5Fu) nanoparticles and investigate its anti-carcinoma effect and toxicity. METHODS: CTS-Pasp-5Fu nanoparticles were synthesized by ionic gelatification. Male BABL/c nude mice were injected with SGC-7901 gastric carcinoma cell line mass to establish a human gastric carcinoma model. They were randomly allocated into 4 groups: CTS-Pasp-5Fu (containing 5-Fu 1.25 mg/kg), 5-Fu (1.25 mg/kg), CTS-Pasp and normal saline groups. Tumor weight was measured and assay of colony forming unit-granulocyte and macrophage (CFU-GM) was performed. The structural change of cells and tissues was observed and the Bax and Bcl-2 genes were detected. RESULTS: Compared with normal saline, the inhibition rates of tumor growth for the CTS-Pasp, 5-Fu and CTS-Pasp-5Fu groups were 5.58%, 58.69% and 70.82%, respectively. The tumor inhibition rates for the CTS-Pasp, 5-Fu and CTS-Pasp-5Fu groups were 5.09%, 65.3% and 72.79%, respectively. There was a significant decrease in the number of CFU-GMformation and increase of total bilirubin, and alanine aminotransferase in the 5-Fu group, but no change in those of the other three groups. There was no change in white blood cell count and creatinine among the four groups. Pathological section of liver and nephridial tissues showed that the damage in the 5-Fu group was more severe than that in the CTS-Pasp-5Fu group. 5-Fu and CTS-Pasp-5Fu groups could both down-regulate the Bcl-2 expression and up-regulate the Bax expression to different extent, and the accommodate effect of CTS-Pasp-5Fu was more obvious than 5-Fu. CONCLUSION: The tumor inhibition rate of CTS-Pasp-5Fu nanoparticles is much higher than that of 5-Fu alone.
基金financial supports from the National Natural Science Foundation of China(Nos.51974364,51904339)Hunan Province for Clean and Efficient Utilization of Strategic Calcium-containing Mineral,China(No.2018TP1002)。
文摘Environmentally friendly flotation reagent,polyaspartic acid(PAPA),was tested as a potential selective depressant in the flotation separation of chalcopyrite and Cu-activated sphalerite.The depression mechanism of PAPA was revealed by contact angle measurements,Zeta potential measurements,Fourier transform infrared spectroscopy(FT-IR)analysis and inductively coupled plasma(ICP)measurement.The micro-flotation tests with single minerals showed that PAPA selectively depressed Cu-activated sphalerite,while chalcopyrite remained floatable.Moreover,a concentrate containing 31.40%Cu with a recovery of 92.43%was obtained in flotation tests of artificially mixed minerals.Results of contact angle measurements,Zeta potential measurements and FT-IR spectrum revealed that PAPA exerted a much stronger adsorption on Cu-activated sphalerite surface than on chalcopyrite surface,preventing the further adsorption of sodium diethyl dithiocarbamate(DDTC)on its surface.ICP measurements indicated that PAPA had an excellent complexing ability with Cu^(2+)in flotation pulp,weakening the activation of Cu species on sphalerite surface and producing selective depression.
基金The authors gratefully acknowledge the financial support of the National Natural Science Foundation of China(No.41276074)National Basic Research Program of China(No.2014CB643304).
文摘The inhibition behavior of polyaspartic acid(PASP)as an environment-friendly corrosion inhibitor for WE43 magnesium alloy was investigated in 3.5 wt.%NaCl solution by means for EIS measurement,potentiodynamic polarization curve,and scanning electron microscopy.The results show that PASP can inhibit the corrosion of WE43 magnesium alloy.The maximum inhibition efficiency is achieved when PASP concentration is 400 ppm in this study.
基金Supported by Key Project of the National Twelfth-five Year Research Program of China(2011BAD11B02)~~
文摘[Objective] This study was conducted to analyze the effects of humic acid and PASP on the growth of broccoli to provide a basis for fertilizer application.[Method] A field experiment was carried out to investigate broccoli growth, yield and quality by using humic acids and PASP as fertilizer synergists in the mixture with compound fertilizer. [Results] The treatment of 5‰ humic acid ＋ 3‰ PASP ＋ compound fertilizer exhibited the plant height, stem diameter and yield increased by8.3%, 13.3% and 10.3%, respectively, and thus was the best; and the treatment showed a single curd weight of 478 g and a commodity rate of 89.4%, and had lower economic cost than treatment of 10‰ humic acid ＋ 6‰ PASP ＋ compound fertilizer. [Conclusion] In summary, 5‰ humic acid ＋ 3‰ PASP ＋ compound fertilizer is suitable for wide application in broccoli culture.
