SO2 is very rapidly hydrated to sulfurous acid in water solution at pH value above 6.0, whereby sulfite is yielded from the disassociation of protons. We aimed to improve the sulfite transformation efficiency and prov...SO2 is very rapidly hydrated to sulfurous acid in water solution at pH value above 6.0, whereby sulfite is yielded from the disassociation of protons. We aimed to improve the sulfite transformation efficiency and provide a basis for the direct utilization of SO2 from flue gas by a microalgal suspension. Chlorella sp. XQ-20044 was cultured in a medium with 20 mmol/L sodium sulfite under different physicochemical conditions. Under light conditions, sulfite concentration in the algal suspension reduced linearly over time, and was completely converted into sulfate within 8 h. The highest sulfite transformation rate (3.25 mmol/ (L.h)) was obtained under the following conditions: 35℃, light intensity of 300 μmol/(m^2·s), NaHCO3 concentration of 6 g/L, initial cell density (OD540) of 0.8 and pH of 9-10. There was a positive correlation between sulfite transformation rate and the growth of Chlorella, with the conditions favorable to algal growth giving better sulfite transformation. Although oxygen in the air plays a role in the transformation of SO3^2- to SO^2-, the transformation is mainly dependent on the metabolic activity of algal cells. Chlorella sp. XQ-20044 is capable of tolerating high sulfite concentration, and can utilize sulfite as the sole sulfur source for maintaining healthy growth. We found that sulfite 〈20 mmol/L had no obvious effect on the total lipid content and fatty acid profiles of the algae, Thus, the results suggest it is feasible to use flue gas for the mass production of feedstock for biodiesel using Chlorella sp. XQ-20044, without preliminary removal of SO2, assuming there is adequate control of the pH.展开更多
AIM:To investigate colorectal uptake of solid lipid nanoparticles(SLNs) in mice receiving different doses of 1,2-dimethylhydrazine(DMH) using magnetic resonance(MR) and laser-scanning confocal fluorescence microscope(...AIM:To investigate colorectal uptake of solid lipid nanoparticles(SLNs) in mice receiving different doses of 1,2-dimethylhydrazine(DMH) using magnetic resonance(MR) and laser-scanning confocal fluorescence microscope(LSCFM) imaging.METHODS:Eight mice were sacrificed in a pilot study to establish the experimental protocol and to visualize colorectal uptake of SLNs in normal mice.Gadopentetate dimeglumine and fluorescein isothiocyanate(FITC)-loaded SLN(Gd-FITC-SLN) enemas were performed on mice receiving DMH for 10 wk(group 1,n = 9) or 16 wk(group 2,n = 7) and FITC-SLN enema wasperformed on 4 DMH-treated mice(group 3).Pre-and post-enema MR examinations were made to visualize the air-inflated distal colorectum.Histological and LSCFM examinations were performed to verify colorectal malignancy and to track the distribution of SLNs.RESULTS:Homogeneous enhancement and dense fluorescence(FITC) deposition in colorectal wall were observed in normal mice and 1 DMH-treated mouse(group 1) on fluid attenuated inversion recovery(FLAIR) and LSCFM images,respectively.Heterogeneous mural enhancement was found in 6 mice(4 in group 1;2 in group 2).No visible mural enhancement was observed in the other mice.LSCFM imaging revealed linear fluorescence deposition along the colorectal mucosa in all groups.Nine intraluminal masses and one prolapsed mass were detected by MR imaging with different enhancement modes and pathologies.Interstitial FITC deposition was identified where obvious enhancement was observed in FLAIR images.Bladder imaging agent accumulations were observed in 11 of 16 DMH-treated mice of groups 1 and 2.CONCLUSION:There are significant differences in colorectal uptake and distribution of SLNs between normal and DMH-treated mice,which may provide a new mechanism of contrast for MR colonography.展开更多
Lipids were extracted from organs of the starfish Asterias amurens& associated with different treatments (raw-control, boiling and heating), and then analyzed for lipid content, lipid oxidation index, lipid classes...Lipids were extracted from organs of the starfish Asterias amurens& associated with different treatments (raw-control, boiling and heating), and then analyzed for lipid content, lipid oxidation index, lipid classes and fatty acid composition. Results showed that boiling softened the hard starfish shells, thus facilitating the collection of starfish organs. As compared with raw organs, the boiled organs had lower water content and higher lipid content, possibly due to the loss of water-holding capacity caused by pro- tein denaturation. Both boiling and heating increased the peroxide value (PV), thiobarbituric acid (TBA) value and carbon value (CV) of lipids. Despite slight increases in the content of complex lipids, associated lipid composition had no substantial variations upon boiling and heating. For simple lipids, the content of 1, 2-diglyceride decreased in boiled and heated organs, with free fatty acids observed on thin layer chromatography (TLC). However, neither boiling nor heating significantly changed the fatty acid composi- tions of simple or complex lipids in starfish organs, suggesting that these two treatments had no significant effects on complex lipids in starfish organs. Together, our results indicated that boiling of starfish soon after capture facilitated the handling and extraction of useful complex lipids consisting of abundant glucosylceramide and eicosapentaenoic acid (EPA)-bounded phospholipids.展开更多
基金Supported by the National Natural Science Foundation of China(No.CNSF31272680)the National High Technology Research and Development Program of China(No.2013AA065805)
文摘SO2 is very rapidly hydrated to sulfurous acid in water solution at pH value above 6.0, whereby sulfite is yielded from the disassociation of protons. We aimed to improve the sulfite transformation efficiency and provide a basis for the direct utilization of SO2 from flue gas by a microalgal suspension. Chlorella sp. XQ-20044 was cultured in a medium with 20 mmol/L sodium sulfite under different physicochemical conditions. Under light conditions, sulfite concentration in the algal suspension reduced linearly over time, and was completely converted into sulfate within 8 h. The highest sulfite transformation rate (3.25 mmol/ (L.h)) was obtained under the following conditions: 35℃, light intensity of 300 μmol/(m^2·s), NaHCO3 concentration of 6 g/L, initial cell density (OD540) of 0.8 and pH of 9-10. There was a positive correlation between sulfite transformation rate and the growth of Chlorella, with the conditions favorable to algal growth giving better sulfite transformation. Although oxygen in the air plays a role in the transformation of SO3^2- to SO^2-, the transformation is mainly dependent on the metabolic activity of algal cells. Chlorella sp. XQ-20044 is capable of tolerating high sulfite concentration, and can utilize sulfite as the sole sulfur source for maintaining healthy growth. We found that sulfite 〈20 mmol/L had no obvious effect on the total lipid content and fatty acid profiles of the algae, Thus, the results suggest it is feasible to use flue gas for the mass production of feedstock for biodiesel using Chlorella sp. XQ-20044, without preliminary removal of SO2, assuming there is adequate control of the pH.
基金Supported by National Natural Science Foundation of China,No.30670610
文摘AIM:To investigate colorectal uptake of solid lipid nanoparticles(SLNs) in mice receiving different doses of 1,2-dimethylhydrazine(DMH) using magnetic resonance(MR) and laser-scanning confocal fluorescence microscope(LSCFM) imaging.METHODS:Eight mice were sacrificed in a pilot study to establish the experimental protocol and to visualize colorectal uptake of SLNs in normal mice.Gadopentetate dimeglumine and fluorescein isothiocyanate(FITC)-loaded SLN(Gd-FITC-SLN) enemas were performed on mice receiving DMH for 10 wk(group 1,n = 9) or 16 wk(group 2,n = 7) and FITC-SLN enema wasperformed on 4 DMH-treated mice(group 3).Pre-and post-enema MR examinations were made to visualize the air-inflated distal colorectum.Histological and LSCFM examinations were performed to verify colorectal malignancy and to track the distribution of SLNs.RESULTS:Homogeneous enhancement and dense fluorescence(FITC) deposition in colorectal wall were observed in normal mice and 1 DMH-treated mouse(group 1) on fluid attenuated inversion recovery(FLAIR) and LSCFM images,respectively.Heterogeneous mural enhancement was found in 6 mice(4 in group 1;2 in group 2).No visible mural enhancement was observed in the other mice.LSCFM imaging revealed linear fluorescence deposition along the colorectal mucosa in all groups.Nine intraluminal masses and one prolapsed mass were detected by MR imaging with different enhancement modes and pathologies.Interstitial FITC deposition was identified where obvious enhancement was observed in FLAIR images.Bladder imaging agent accumulations were observed in 11 of 16 DMH-treated mice of groups 1 and 2.CONCLUSION:There are significant differences in colorectal uptake and distribution of SLNs between normal and DMH-treated mice,which may provide a new mechanism of contrast for MR colonography.
基金supported by the International Science and Technology Cooperation Program of China(GrantNo.2010DFA31330)partically by the Sakura Program of Japan Society for Promotion of Science
文摘Lipids were extracted from organs of the starfish Asterias amurens& associated with different treatments (raw-control, boiling and heating), and then analyzed for lipid content, lipid oxidation index, lipid classes and fatty acid composition. Results showed that boiling softened the hard starfish shells, thus facilitating the collection of starfish organs. As compared with raw organs, the boiled organs had lower water content and higher lipid content, possibly due to the loss of water-holding capacity caused by pro- tein denaturation. Both boiling and heating increased the peroxide value (PV), thiobarbituric acid (TBA) value and carbon value (CV) of lipids. Despite slight increases in the content of complex lipids, associated lipid composition had no substantial variations upon boiling and heating. For simple lipids, the content of 1, 2-diglyceride decreased in boiled and heated organs, with free fatty acids observed on thin layer chromatography (TLC). However, neither boiling nor heating significantly changed the fatty acid composi- tions of simple or complex lipids in starfish organs, suggesting that these two treatments had no significant effects on complex lipids in starfish organs. Together, our results indicated that boiling of starfish soon after capture facilitated the handling and extraction of useful complex lipids consisting of abundant glucosylceramide and eicosapentaenoic acid (EPA)-bounded phospholipids.