Objective： To explore water soluble metabolite features of brain tumor specimens with HRMAS-^1HMRS and its potential clinical value. Methods： There were thirty cases of pathologically proven brain tumor, including 6...Objective： To explore water soluble metabolite features of brain tumor specimens with HRMAS-^1HMRS and its potential clinical value. Methods： There were thirty cases of pathologically proven brain tumor, including 6 Ⅰ-Ⅱ grade astrocytomas, 7 Ⅲ grade anaplastic astrocytomas, 10 IV grade glioblastomas and 7 meningiomas. Used Varian Company 600 MHz spectrometer with the Nano-probe for acquisition HRMASJHMRS, which was postprocessed with jMRUI 3.2 version software. These metabolic probability and their ratios to Cr were summed. Results： （1） HRMAS-^1HMRS could resolve NAA, PCr/Cr, GPC ± PCho ± Cho, Glu/GIn, Gly, Tau, Ala, Lac, ml and so on. All samples showed Lac, 6 samples showed unknown single peak at 3.72 ppm or 3.90 ppm. （2） The mean Cho/Cr of 6 Ⅰ-ⅡI grade astrocytomas was 2.42 ± 1.01 （P = 0.003, compared with glioblastoma）. The mean Cho/Cr of 7 anaplastic astrocytomas was 3.48 ± 0.59 （P = 0.01, compared with glioblastoma）. The Cho/Cr of 10 glioblastomas broadly ranged from 0.9 to 11.3 （mean 5.40 ± 1.23）. From Ⅰ-Ⅱ grade astrocytoma to glioblastoma, Ala/Cr, Tau/Cr and Gly/Cr trends were increased; the mean Ala/Cr of glioma was 0.31 ± 0.13. （3） Meningiomas showed higher Ala and Cho. Their Cr was lower than that of gliomas. 4/7 cases had no NAA, 3/7 patients had lower NAA. Mean Cho/Cr was 3.56 ± 1.01, Ala/Cr was 0.53 ±0.28 （P = 0.006, compared with glioma）. Conclusion： HRMAS-^1HMRS can show further details in vivo MRS, resolve in vivo spectroscopic metabolite of Cho compound and differentiate the extent of benign and malignant glioma. With the increase in the malignant degree of gliomas, Cho, ml, Ala, Tau and Gly will increase. HRMAS-^1HMRS is the only method of isotropic spectroscopy for pathological specimens.展开更多
A hierarchical beta zeolite synthesized by quasi-solid phase conversion method was characterized by BET, scanning electron microscope （SEM）, transmission electron microscope （TEM）, X-ray diffraction （XRD）, tempe...A hierarchical beta zeolite synthesized by quasi-solid phase conversion method was characterized by BET, scanning electron microscope （SEM）, transmission electron microscope （TEM）, X-ray diffraction （XRD）, temperature-programmed desorption of ammonia （NH3-TPD）, 27A1 and 295i magic angle spinning nuclear magnetic resonance （27A1 and 29Si MAS NMR）, and its catalytic performance was compared with that of conventional microporous beta zeolite for liquid phase transalkylation of multi-secbutylbenzenes （MSBBs） with benzene. The results indicate that the hierarchical beta zeolite consists of nanosized crystals with a meso/ microporous structure and has stronger acid strength than the microporous beta zeolite. The higher conversion oftri-secbutylbenzene （TSBB） and selectivity ofsec-butylbenzene （SBB） are achieved on hierarchical beta zeolite than microporous beta zeolite, while the conversion of di-secbutylbenzene （DSBB） is slightly higher. The improvement of catalytic performance over hierarchical beta zeolite can be ascribed to the presence of mesopores, nanosized crystals and stronger acidity.展开更多
Forest management practices such as prescribed burning and thinning in forest ecosystems may alter the properties of soil organic matter （SOM）. In this study, surface softs from field plots in the Bankhead National ...Forest management practices such as prescribed burning and thinning in forest ecosystems may alter the properties of soil organic matter （SOM）. In this study, surface softs from field plots in the Bankhead National Forest, Alabama, USA, were used to investigate possible SOM transformations induced by thinning and burning. Elemental analysis and solid-state 13C cross polarization magic angle spinning nuclear magnetic resonance （13C CPMAS NMR） spectroscopy were used to characterize SOM fractions in whole soils, humic substances, and density fractions. Our data revealed that the changes in SOM fractions due to the repeated burning carried out in the forest ecosystem studied were involved mainly with alkyl C, O-alkyl C, and carbohydrate functional groups, implying that most prominent reactions that occurred involved dehydrogenation, de-oxygenation, and decarboxylation. In addition, burning and thinning might have also affected the distribution and composition of free and occluded particulate SOM fractions. The limited structural changes in SOM fractions suggested that low-intensity prescribed fire in the forest ecosystem studied will not create major structural changes in SOM fractions.展开更多
文摘锰铋稀土 (Mn Bi RE)薄膜具有较大的磁光克尔转角 θk,因而作为良好的磁光信息存储材料 .用真空蒸镀方法制备了 Mn Bi RE (RE=Ce、 Pr、 Nd、 Sm)薄膜 ,考察了温度变化对其矫顽力、磁光克尔转角等性能的影响 .通过信息的写入 ,分析了这些样品的读写特性并与四层结构 Tb Fe
文摘Objective： To explore water soluble metabolite features of brain tumor specimens with HRMAS-^1HMRS and its potential clinical value. Methods： There were thirty cases of pathologically proven brain tumor, including 6 Ⅰ-Ⅱ grade astrocytomas, 7 Ⅲ grade anaplastic astrocytomas, 10 IV grade glioblastomas and 7 meningiomas. Used Varian Company 600 MHz spectrometer with the Nano-probe for acquisition HRMASJHMRS, which was postprocessed with jMRUI 3.2 version software. These metabolic probability and their ratios to Cr were summed. Results： （1） HRMAS-^1HMRS could resolve NAA, PCr/Cr, GPC ± PCho ± Cho, Glu/GIn, Gly, Tau, Ala, Lac, ml and so on. All samples showed Lac, 6 samples showed unknown single peak at 3.72 ppm or 3.90 ppm. （2） The mean Cho/Cr of 6 Ⅰ-ⅡI grade astrocytomas was 2.42 ± 1.01 （P = 0.003, compared with glioblastoma）. The mean Cho/Cr of 7 anaplastic astrocytomas was 3.48 ± 0.59 （P = 0.01, compared with glioblastoma）. The Cho/Cr of 10 glioblastomas broadly ranged from 0.9 to 11.3 （mean 5.40 ± 1.23）. From Ⅰ-Ⅱ grade astrocytoma to glioblastoma, Ala/Cr, Tau/Cr and Gly/Cr trends were increased; the mean Ala/Cr of glioma was 0.31 ± 0.13. （3） Meningiomas showed higher Ala and Cho. Their Cr was lower than that of gliomas. 4/7 cases had no NAA, 3/7 patients had lower NAA. Mean Cho/Cr was 3.56 ± 1.01, Ala/Cr was 0.53 ±0.28 （P = 0.006, compared with glioma）. Conclusion： HRMAS-^1HMRS can show further details in vivo MRS, resolve in vivo spectroscopic metabolite of Cho compound and differentiate the extent of benign and malignant glioma. With the increase in the malignant degree of gliomas, Cho, ml, Ala, Tau and Gly will increase. HRMAS-^1HMRS is the only method of isotropic spectroscopy for pathological specimens.
文摘A hierarchical beta zeolite synthesized by quasi-solid phase conversion method was characterized by BET, scanning electron microscope （SEM）, transmission electron microscope （TEM）, X-ray diffraction （XRD）, temperature-programmed desorption of ammonia （NH3-TPD）, 27A1 and 295i magic angle spinning nuclear magnetic resonance （27A1 and 29Si MAS NMR）, and its catalytic performance was compared with that of conventional microporous beta zeolite for liquid phase transalkylation of multi-secbutylbenzenes （MSBBs） with benzene. The results indicate that the hierarchical beta zeolite consists of nanosized crystals with a meso/ microporous structure and has stronger acid strength than the microporous beta zeolite. The higher conversion oftri-secbutylbenzene （TSBB） and selectivity ofsec-butylbenzene （SBB） are achieved on hierarchical beta zeolite than microporous beta zeolite, while the conversion of di-secbutylbenzene （DSBB） is slightly higher. The improvement of catalytic performance over hierarchical beta zeolite can be ascribed to the presence of mesopores, nanosized crystals and stronger acidity.
基金supported by the USDA National Institute of Food and Agriculture(NIFA),Evans Allen Grant,USA(No.224120)the National Science Foundation(NSF-CREST-CFEA),USA(No.1036600)the Agricultural Experimental Station,Alabama A&M University,Alabama,USA(Journal#:660)
文摘Forest management practices such as prescribed burning and thinning in forest ecosystems may alter the properties of soil organic matter （SOM）. In this study, surface softs from field plots in the Bankhead National Forest, Alabama, USA, were used to investigate possible SOM transformations induced by thinning and burning. Elemental analysis and solid-state 13C cross polarization magic angle spinning nuclear magnetic resonance （13C CPMAS NMR） spectroscopy were used to characterize SOM fractions in whole soils, humic substances, and density fractions. Our data revealed that the changes in SOM fractions due to the repeated burning carried out in the forest ecosystem studied were involved mainly with alkyl C, O-alkyl C, and carbohydrate functional groups, implying that most prominent reactions that occurred involved dehydrogenation, de-oxygenation, and decarboxylation. In addition, burning and thinning might have also affected the distribution and composition of free and occluded particulate SOM fractions. The limited structural changes in SOM fractions suggested that low-intensity prescribed fire in the forest ecosystem studied will not create major structural changes in SOM fractions.
