The quantitative determination of the mass fractions of precipitates in steels is very difficult using traditional materials characterization techniques. The Rietveld full-pattern fitting algorithm was introduced to s...The quantitative determination of the mass fractions of precipitates in steels is very difficult using traditional materials characterization techniques. The Rietveld full-pattern fitting algorithm was introduced to solve this problem. The precipitated multicomponents’ mass fraction of M3C, MC, M7C3 and M23C6 were evaluated precisely and relatively quickly. It is found evolution of carbides apparently occurs during tempering at high temperatures, and a two-step transformation mechanism is proposed for M7C3 during early tempering treatment. The method is an effective way on the investigation of precipitation kinetics, which may play a promising role in propertities’ enhancement and design of the heat-resistant steels.展开更多
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
The main methods of the second phase quantitative analysis in current material science researches are manual recognition and extracting by using software such as Image Tool and Nano Measurer. The weaknesses such as hi...The main methods of the second phase quantitative analysis in current material science researches are manual recognition and extracting by using software such as Image Tool and Nano Measurer. The weaknesses such as high labor intensity and low accuracy statistic results exist in these methods. In order to overcome the shortcomings of the current methods, the Ω phase in A1-Cu-Mg-Ag alloy is taken as the research object and an algorithm based on the digital image processing and pattern recognition is proposed and implemented to do the A1 alloy TEM （transmission electron microscope） digital images process and recognize and extract the information of the second phase in the result image automatically. The top-hat transformation of the mathematical morphology, as well as several imaging processing technologies has been used in the proposed algorithm. Thereinto, top-hat transformation is used for elimination of asymmetric illumination and doing Multi-layer filtering to segment Ω phase in the TEM image. The testing results are satisfied, which indicate that the Ω phase with unclear boundary or small size can be recognized by using this method. The omission of these two kinds of Ω phase can be avoided or significantly reduced. More Ω phases would be recognized （growing rate minimum to 2% and maximum to 400% in samples）, accuracy of recognition and statistics results would be greatly improved by using this method. And the manual error can be eliminated. The procedure recognizing and making quantitative analysis of information in this method is automatically completed by the software. It can process one image, including recognition and quantitative analysis in 30 min, but the manual method such as using Image Tool or Nano Measurer need 2 h or more. The labor intensity is effectively reduced and the working efficiency is greatly improved.展开更多
以吡嗪作为内标物,采用1 H NMR方法对葛根素的含量进行测定。对葛根素的1 H NMR谱进行分析,考察了脉冲宽度、延迟时间、扫描次数等对测定结果的影响,确定了特征峰峰面积截取范围,根据峰面积积分值计算样品含量。葛根素定量分析最佳参数...以吡嗪作为内标物,采用1 H NMR方法对葛根素的含量进行测定。对葛根素的1 H NMR谱进行分析,考察了脉冲宽度、延迟时间、扫描次数等对测定结果的影响,确定了特征峰峰面积截取范围,根据峰面积积分值计算样品含量。葛根素定量分析最佳参数为:室温,匀场3次,脉冲宽度18μs,延迟时间1.5μs,扫描次数48。计算含量的特征峰选择为C7-H或C4-H峰。展开更多
目的探讨距骨骨软骨损伤(osteochondral lesions of the talus,OLT)软骨基质金属蛋白酶-1(matrix metalloproteinase-1,MMP-1)的表达与磁共振T2值之间的关系及其在距骨骨软骨损伤的机制。材料与方法收集30例踝关节距骨骨软骨损伤行微创...目的探讨距骨骨软骨损伤(osteochondral lesions of the talus,OLT)软骨基质金属蛋白酶-1(matrix metalloproteinase-1,MMP-1)的表达与磁共振T2值之间的关系及其在距骨骨软骨损伤的机制。材料与方法收集30例踝关节距骨骨软骨损伤行微创治疗术患者及30名健康志愿者,均行3.0 T常规踝关节磁共振成像(magnetic resonance imaging,MRI)及T2-mapping功能成像,测量距骨软骨T2值。术后离体距骨骨软骨行苏木精-伊红染色(hematoxylin-eosin staining,HE)和Western Blot法分析距骨骨软骨MMP-1的表达,统计学分析距骨骨软骨T2值与MMP-1蛋白表达的相关性。结果距骨骨软骨损伤以内中侧最为多见(磁共振6分区法),距骨骨软骨T2值随软骨损伤Mankin分级明显增大(P<0.05)。软骨MMP-1蛋白表达高级别与低级别差异明显(P<0.05)。软骨T2值与软骨MMP-1表达呈线性相关趋势,Pearson分析距骨骨软骨损伤T2值增加与MMP-1蛋白表达增加呈直线性正相关(r=0.821,P<0.0001)。结论距骨骨软骨损伤以内中侧最为多见,距骨骨软骨磁共振T2值随软骨损伤分级逐级递增;距骨骨软骨损伤磁共振T2值与MMP-1蛋白表达呈正相关,距骨骨软骨磁共振T2-mapping功能成像T2值定量分析可在体、无创性预测不同级别软骨损伤MMP-1蛋白的表达含量,为临床治疗OLT提供影像学定量依据。展开更多
基金Funded by the New Products Development Research Projects of Shang-hai Baoshan Iron & Steel Research Institute(X08ECEJ160)
文摘The quantitative determination of the mass fractions of precipitates in steels is very difficult using traditional materials characterization techniques. The Rietveld full-pattern fitting algorithm was introduced to solve this problem. The precipitated multicomponents’ mass fraction of M3C, MC, M7C3 and M23C6 were evaluated precisely and relatively quickly. It is found evolution of carbides apparently occurs during tempering at high temperatures, and a two-step transformation mechanism is proposed for M7C3 during early tempering treatment. The method is an effective way on the investigation of precipitation kinetics, which may play a promising role in propertities’ enhancement and design of the heat-resistant steels.
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Project(51171209)supported by the National Natural Science Foundation of China
文摘The main methods of the second phase quantitative analysis in current material science researches are manual recognition and extracting by using software such as Image Tool and Nano Measurer. The weaknesses such as high labor intensity and low accuracy statistic results exist in these methods. In order to overcome the shortcomings of the current methods, the Ω phase in A1-Cu-Mg-Ag alloy is taken as the research object and an algorithm based on the digital image processing and pattern recognition is proposed and implemented to do the A1 alloy TEM （transmission electron microscope） digital images process and recognize and extract the information of the second phase in the result image automatically. The top-hat transformation of the mathematical morphology, as well as several imaging processing technologies has been used in the proposed algorithm. Thereinto, top-hat transformation is used for elimination of asymmetric illumination and doing Multi-layer filtering to segment Ω phase in the TEM image. The testing results are satisfied, which indicate that the Ω phase with unclear boundary or small size can be recognized by using this method. The omission of these two kinds of Ω phase can be avoided or significantly reduced. More Ω phases would be recognized （growing rate minimum to 2% and maximum to 400% in samples）, accuracy of recognition and statistics results would be greatly improved by using this method. And the manual error can be eliminated. The procedure recognizing and making quantitative analysis of information in this method is automatically completed by the software. It can process one image, including recognition and quantitative analysis in 30 min, but the manual method such as using Image Tool or Nano Measurer need 2 h or more. The labor intensity is effectively reduced and the working efficiency is greatly improved.
文摘以吡嗪作为内标物,采用1 H NMR方法对葛根素的含量进行测定。对葛根素的1 H NMR谱进行分析,考察了脉冲宽度、延迟时间、扫描次数等对测定结果的影响,确定了特征峰峰面积截取范围,根据峰面积积分值计算样品含量。葛根素定量分析最佳参数为:室温,匀场3次,脉冲宽度18μs,延迟时间1.5μs,扫描次数48。计算含量的特征峰选择为C7-H或C4-H峰。
