AIM: To study liver cell apoptosis caused by the toxicity of selenium and observe the alteration of choline compounds using in vitro 9.4T high resolution magnetic resonance spectroscopy. METHODS: Twenty male Wistar ra...AIM: To study liver cell apoptosis caused by the toxicity of selenium and observe the alteration of choline compounds using in vitro 9.4T high resolution magnetic resonance spectroscopy. METHODS: Twenty male Wistar rats were randomly divided into two groups. The rats in the treatment group were intraperitoneally injected with sodium selenite and the control group with distilled water. All rats were sacrifi ced and the livers were dissected. 1H-MRS data were collected using in vitro 9.4T high resolution magnetic resonance spectrometer. Spectra were processed using XWINNMR and MestRe-c 4.3. HE and TUNEL staining was employed to detect and confi rm the change of liver cells. RESULTS: Good 1H-MR spectra of perchloric acid extract from liver tissue of rats were obtained. The conventional metabolites were detected and assigned. Concentrations of different ingredient choline compounds in treatment group vs control group were as follows: total choline compounds,5.08 ± 0.97 mmol/L vs 3.81 ± 1.16 mmol/L (P = 0.05); and free choline,1.07 ± 0.23 mmol/L vs 0.65 ± 0.20 mmol/L (P = 0.00). However,there was no statistical signif icance between the two groups. The hepatic sinus and cellular structure of hepatic cells in treatmentgroup were abnormal. Apoptosis of hepatic cells was confi rmed by TUNEL assay. CONCLUSION: High dose selenium compounds can cause the rat liver lesion and induce cell apoptosis in vivo. High resolution 1H-MRS in vitro can detect diversified metabolism. The changing trend for different ingredient of choline compounds is not completely the same at early period of apoptosis.展开更多
Acid mine drainage presents an important threat to cementitious structures.This study is aimed at investigating the effect of cellulose nanocrystals(CNCs)on the acid resistance of cementitious composites.CNCs were add...Acid mine drainage presents an important threat to cementitious structures.This study is aimed at investigating the effect of cellulose nanocrystals(CNCs)on the acid resistance of cementitious composites.CNCs were added to mortar mixtures as additives at cement volume ratios of 0.2vol%,0.4vol%,1.0vol%,and 1.5vol%.After 28 d of standard curing,the samples were immersed in a sulfuric acid with a pH value of 2 for 75 d.The unconfined compressive strength(UCS)test,the density,water absorption,void volume test,and thermogravimetric analysis were carried out to investigate the properties of CNC mixtures before sulfuric acid immersion.It was found that the addition of CNC reduced the volume of permeable voids and increased the hydration degree and mechanical strength of the samples.Changes in mass and length were monitored during immersion to evaluate the acid resistance of mixtures.The mixture with 0.4vol%CNC showed a reduced mass change and length change indicating its improved acid resistance.展开更多
基金The National Natural Science Foundation of China,No.30570480
文摘AIM: To study liver cell apoptosis caused by the toxicity of selenium and observe the alteration of choline compounds using in vitro 9.4T high resolution magnetic resonance spectroscopy. METHODS: Twenty male Wistar rats were randomly divided into two groups. The rats in the treatment group were intraperitoneally injected with sodium selenite and the control group with distilled water. All rats were sacrifi ced and the livers were dissected. 1H-MRS data were collected using in vitro 9.4T high resolution magnetic resonance spectrometer. Spectra were processed using XWINNMR and MestRe-c 4.3. HE and TUNEL staining was employed to detect and confi rm the change of liver cells. RESULTS: Good 1H-MR spectra of perchloric acid extract from liver tissue of rats were obtained. The conventional metabolites were detected and assigned. Concentrations of different ingredient choline compounds in treatment group vs control group were as follows: total choline compounds,5.08 ± 0.97 mmol/L vs 3.81 ± 1.16 mmol/L (P = 0.05); and free choline,1.07 ± 0.23 mmol/L vs 0.65 ± 0.20 mmol/L (P = 0.00). However,there was no statistical signif icance between the two groups. The hepatic sinus and cellular structure of hepatic cells in treatmentgroup were abnormal. Apoptosis of hepatic cells was confi rmed by TUNEL assay. CONCLUSION: High dose selenium compounds can cause the rat liver lesion and induce cell apoptosis in vivo. High resolution 1H-MRS in vitro can detect diversified metabolism. The changing trend for different ingredient of choline compounds is not completely the same at early period of apoptosis.
基金financially supported by the Natural Sciences and Engineering Research Council of Canada(No.RGPIN-2017-05537)the Alberta Innovates CNC Challenge 3.0 Grant(No.BFC 18009)。
文摘Acid mine drainage presents an important threat to cementitious structures.This study is aimed at investigating the effect of cellulose nanocrystals(CNCs)on the acid resistance of cementitious composites.CNCs were added to mortar mixtures as additives at cement volume ratios of 0.2vol%,0.4vol%,1.0vol%,and 1.5vol%.After 28 d of standard curing,the samples were immersed in a sulfuric acid with a pH value of 2 for 75 d.The unconfined compressive strength(UCS)test,the density,water absorption,void volume test,and thermogravimetric analysis were carried out to investigate the properties of CNC mixtures before sulfuric acid immersion.It was found that the addition of CNC reduced the volume of permeable voids and increased the hydration degree and mechanical strength of the samples.Changes in mass and length were monitored during immersion to evaluate the acid resistance of mixtures.The mixture with 0.4vol%CNC showed a reduced mass change and length change indicating its improved acid resistance.
