Objective A highly sensitive and rapid high‐performance liquid chromatography method with pre‐column derivatization with 4‐fluoro‐7‐nitrobenzofurazan was developed for determination of taurine in biological sampl...Objective A highly sensitive and rapid high‐performance liquid chromatography method with pre‐column derivatization with 4‐fluoro‐7‐nitrobenzofurazan was developed for determination of taurine in biological samples,including plasma,brain,and liver.Methods The optimum derivatization reaction temperature was 70℃,and at this temperature the reaction was complete within 3 min.The derivatized taurine was separated using phosphate buffer （0.02 mol/L,pH 6.0）：acetonitrile （84：16,v/v） as the mobile phase at a flow rate of 1.0 mL/min,and a column temperature of 25℃.The taurine derivatives were separated within 20 min （tR：14.5 min） and fluorometrically detected at 530 nm with excitation at 470 nm.Results The intra‐ and the inter‐day coefficients of variation for the method were 5.3% and 7.7%,respectively.The calibration curve was linear from 0.1 μmol/L to 30.0 μmol/L with a correlation coefficient of 0.9995.Conclusion This method can be used to determine the taurine contents in plasma,brain,and liver from normal rats and human plasma.展开更多
We examined a total of 16 children with epileptic encephalopathy using fluorine-18-fluoro-2-deoxy-D-glucose （18F-FDG） positron emission computed tomography （PET）, magnetic resonance imaging （MRI） and electroence...We examined a total of 16 children with epileptic encephalopathy using fluorine-18-fluoro-2-deoxy-D-glucose （18F-FDG） positron emission computed tomography （PET）, magnetic resonance imaging （MRI） and electroencephalography. Children with infantile spasms showed significant mental retardation, severely abnormal electroencephalogram recordings, and bilateral diffuse cerebral cortex hypometabolism with I^F-FDG PET imaging. MRI in these cases showed brain atrophy, multi-micropolygyria, macrogyria, and porencephalia. In cases with Lennox-Gastaut syndrome, 18F-FDG PET showed bilateral diffuse glucose hypometabolism, while MRI showed cortical atrophy, heterotopic gray matter and tuberous sclerosis. MRI in cases with myoclonic encephalopathy demonstrated bilateral frontal and temporal cortical and white matter atrophy and 18F-FDG PET imaging showed bilateral frontal lobe atrophy with reduced bilateral frontal cortex, occipital cortex, temporal cortex and cerebellar glucose uptake. In children who could not be clearly classified, MRI demonstrated cerebral cortical atrophy and ~aF-FDG PET exhibited multifocal glucose hypometabolism. Overall, this study demonstrated that the degree of brain metabolic abnormality was consistent with clinical seizure severity. In addition, ~SF-FDG PET imaging after treatment was consistent with clinical outcomes. These findings indicate that ~SF-FDG PET can be used to assess the severity of brain injury and prognosis in children with epileptic encephalopathy.展开更多
In this study, we developed a simple and sensitive HPLC method for the determination of lisinopril in human plasma. The sample clean-up was carried out by solid-phase extraction(SPE) using a cation-exchange(Strata-SCX...In this study, we developed a simple and sensitive HPLC method for the determination of lisinopril in human plasma. The sample clean-up was carried out by solid-phase extraction(SPE) using a cation-exchange(Strata-SCX~?) extraction cartridge. After a pre-column derivatization with 4-fluoro-7-nitro-2,1,3-benzoxadiazole, the reaction mixture was analyzed on an Agilent Zorbax SB~?-C_(18)(150 mm×4.6 mm, 5 μm). The flow rate was set at 1.0 mL/min. Fluorescence detection was performed at an excitation wavelength of 470 nm and an emission wavelength of 530 nm. The mobile phase consisted of a mixture of methanol and 0.02 M sodium dihydrogen phosphate(pH = 3.0, 60:40, v/v). The average extraction recovery of lisinopril and fluvoxamine(internal standard) was >85%. The method exhibited a linear calibration curve over the concentration range of 1–1000 ng/mL with a correlation coefficient(r^2) of ≥0.98 and a limit of quantification(LOQ) equal to 2 ng/mL. The within-run and between-run precisions were satisfactory with an RSD of 3.8%–13.7%(accuracy: from 95.0% to 96.4%) and 4.273%–14.3%(accuracy: from 94.4% to 98.5%), respectively.展开更多
Er3＋-Yb3＋ codoped oxy-fluoro-tungstosilicate glasses with infrared-to-visible frequency upconversion luminescence were prepared by melting quenching in air.The effects of Er3＋ doping on the optical properties of th...Er3＋-Yb3＋ codoped oxy-fluoro-tungstosilicate glasses with infrared-to-visible frequency upconversion luminescence were prepared by melting quenching in air.The effects of Er3＋ doping on the optical properties of the samples were measured by means of techniques such as optical absorption spectra and photoluminescence spectra.The results showed that intense green and red signals centered at 546 and 665 nm,corresponding to the 4S3/2 → 4I15/2 and 4F9/2 → 4I15/2 transitions of Er3＋ by a multiphoton stepwise phonon-assisted excited-state absorption process,respectively,were simultaneously observed by exciting the samples with a diode laser operating at 980 nm at room temperature.The upconversion process was found very sensitive to Er3＋ content at a constant Yb2O3 content of 5 mol.%.With the increase of Er3＋ content from 0.5% to 1.5%,the upconversion intensity increased gradually.Further increasing of Er3＋ content to 3.0% resulted in a significant fluorescence quenching.Moreover,the possible upconversion mechanisms were discussed based on the energy-matching conditions and the quadratic dependence on excitation power.展开更多
A rapid and simple method is presented for determining β-N-oxalyl-α. β- diaminopropionic acid (β -ODAP) and its much less toxic α -isomer (α -ODAP) in Lathyrus sativus. Seed and foliage extracts of Lathyrus sat...A rapid and simple method is presented for determining β-N-oxalyl-α. β- diaminopropionic acid (β -ODAP) and its much less toxic α -isomer (α -ODAP) in Lathyrus sativus. Seed and foliage extracts of Lathyrus sativus were treated with 1-fluoro-2,4-dinitrobenzene (FDNB) and a reversed-phase high-performance liquid chromatographic method for the separation of the derivatives in the pmol range is reported.展开更多
In this paper, we report an improved method for preparing 2--alkoxy 5 fluoro--3H --4--pyrimidone from 2--chloro--5--fluoro--3H--4--pyrimidone and sodium alkoxide under normal pressure at reflux temperature. Some new c...In this paper, we report an improved method for preparing 2--alkoxy 5 fluoro--3H --4--pyrimidone from 2--chloro--5--fluoro--3H--4--pyrimidone and sodium alkoxide under normal pressure at reflux temperature. Some new compounds were synthesized in higher yield by this method.展开更多
The purpose of this paper is to investigate the hydrophobic and mechanical behavior of the fluoro-carbon film on the composite.Fluoro-carbon films were fabricated on C/C and C/SiC composite by microwave ECR chemical v...The purpose of this paper is to investigate the hydrophobic and mechanical behavior of the fluoro-carbon film on the composite.Fluoro-carbon films were fabricated on C/C and C/SiC composite by microwave ECR chemical vapor deposition combined with plasma source ion implantation technology (PSII).The films were investigated in terms of the surface morphology,chemical composition,hydrophobic behavior and mechanical properties.The hydrophobic property was determined by means of contact angle measurements,chemical bond structure was analyzed by fourier-transform infrared spectrum,and critical loading were measured by micro-scratch.The results showed that the fluorine presented mainly in the forms of CF2 group and C=CFx (x=1,2) in the film,the addition of fluorine to the carbon film had a critical influence on the hydrophobicity.Atomic force microscopy (AFM) were used for investigating the effect of surface morphology and roughness on hydrophobicity,it showed that fluoro-carbon films with appropriate surface morphology and roughness could achieve excellent hydrophobicity.展开更多
The title compound VII, 2-fluoro-4-methyl-3-oxo-4-aza-5α-androst-1-ene-17β-carboxylic acid methyl ester （C21H30FNO3, Mr = 363.46）, was prepared through a seven-step reaction from pregnenolone, and characterized by...The title compound VII, 2-fluoro-4-methyl-3-oxo-4-aza-5α-androst-1-ene-17β-carboxylic acid methyl ester （C21H30FNO3, Mr = 363.46）, was prepared through a seven-step reaction from pregnenolone, and characterized by elemental and single-crystal X-ray diffraction analyses as well as IR, MS and 1H-NMR spectra. It is of monoclinic system, space group P21/c with a = 6.3882（7）, b = 9.9033（11）, c = 15.4925（17） , β = 91.923（2）°, V = 979.57（19） 3, Z = 2, Dc = 1.232 mg/m3, μ = 0.088 mm-1, F（000）= 392, R = 0.0465, wR = 0.0989 and λ（MoKα） = 0.71073 . The structure indicates that the four cycles （A： C（1）–C（2）–C（3）–N（1）–C（5）–C（10）, B： C（5）–C（6）–C（7）– C（8）–C（9）–C（10）, C： C（8）–C（14）–C（13）–C（12）–C（11）–C（9）, D： C（14）–C（15）–C（16）–C（17）–C（13）） are in chairand trans-configurations. The results of crystal structure determination show that there exist weak intra-molecular hydrogen bonds, resulting in a two-dimensional supramolecular frame-work of the title compound.展开更多
文摘目的评估Fluoro Jade-c(FJC)染色对深低温停循环术后脑损伤的检测效果。方法建立能模拟临床深低温停循环术后脑损伤的动物模型,将6头中华小型猪行深低温停循环,并保证所有动物存活,对动物脑组织进行病理学检测,动物脑组织灌注固定后行FJC染色,分别取染色阳性和阴性部位,行脑组织苏木精-伊红(Hematoxylin-eosin,HE)染色、尼氏(Nissl)染色、原位凋亡(Terminal deoxynucleotidyl Transferase Biotin-dUTP Nick End Labeling,TUNEL)检测;检测结果对照:FJC染色结果与TUNEL检测、HE染色、Nissl染色结果相对照,验证FJC染色对深低温停循环术后脑损伤检测的准确性和可靠性。结果实验动物术后FJC染色发现有阳性病灶。FJC染色与TUNEL(Kappa值=0.526,P<0.01),Nissl染色(Kappa值=0.555,P<0.01),HE染色(Kappa值=0.491,P<0.01)对比,结果均具有一致性;FJC染色图象更清晰,更易于辨认变性神经元细胞。结论 FJC染色是一种可靠和更方便的检测深低温停循环后脑损伤的方法 。
文摘Objective A highly sensitive and rapid high‐performance liquid chromatography method with pre‐column derivatization with 4‐fluoro‐7‐nitrobenzofurazan was developed for determination of taurine in biological samples,including plasma,brain,and liver.Methods The optimum derivatization reaction temperature was 70℃,and at this temperature the reaction was complete within 3 min.The derivatized taurine was separated using phosphate buffer （0.02 mol/L,pH 6.0）：acetonitrile （84：16,v/v） as the mobile phase at a flow rate of 1.0 mL/min,and a column temperature of 25℃.The taurine derivatives were separated within 20 min （tR：14.5 min） and fluorometrically detected at 530 nm with excitation at 470 nm.Results The intra‐ and the inter‐day coefficients of variation for the method were 5.3% and 7.7%,respectively.The calibration curve was linear from 0.1 μmol/L to 30.0 μmol/L with a correlation coefficient of 0.9995.Conclusion This method can be used to determine the taurine contents in plasma,brain,and liver from normal rats and human plasma.
基金the National Natural Science Foundation of China, No. 81071046the Guangdong Provincial Science and Technology Program, No. 2009B030801250+1 种基金2010 Guangdong Provincial Science and Technology Program, No. 2010B031600159the Guangdong Province Natural Science Foundation, No. 7001205
文摘We examined a total of 16 children with epileptic encephalopathy using fluorine-18-fluoro-2-deoxy-D-glucose （18F-FDG） positron emission computed tomography （PET）, magnetic resonance imaging （MRI） and electroencephalography. Children with infantile spasms showed significant mental retardation, severely abnormal electroencephalogram recordings, and bilateral diffuse cerebral cortex hypometabolism with I^F-FDG PET imaging. MRI in these cases showed brain atrophy, multi-micropolygyria, macrogyria, and porencephalia. In cases with Lennox-Gastaut syndrome, 18F-FDG PET showed bilateral diffuse glucose hypometabolism, while MRI showed cortical atrophy, heterotopic gray matter and tuberous sclerosis. MRI in cases with myoclonic encephalopathy demonstrated bilateral frontal and temporal cortical and white matter atrophy and 18F-FDG PET imaging showed bilateral frontal lobe atrophy with reduced bilateral frontal cortex, occipital cortex, temporal cortex and cerebellar glucose uptake. In children who could not be clearly classified, MRI demonstrated cerebral cortical atrophy and ~aF-FDG PET exhibited multifocal glucose hypometabolism. Overall, this study demonstrated that the degree of brain metabolic abnormality was consistent with clinical seizure severity. In addition, ~SF-FDG PET imaging after treatment was consistent with clinical outcomes. These findings indicate that ~SF-FDG PET can be used to assess the severity of brain injury and prognosis in children with epileptic encephalopathy.
基金The part of a Pham D thesis supported by Tehran University of Medical Sciences(Grant No.23049-92-02-92)
文摘In this study, we developed a simple and sensitive HPLC method for the determination of lisinopril in human plasma. The sample clean-up was carried out by solid-phase extraction(SPE) using a cation-exchange(Strata-SCX~?) extraction cartridge. After a pre-column derivatization with 4-fluoro-7-nitro-2,1,3-benzoxadiazole, the reaction mixture was analyzed on an Agilent Zorbax SB~?-C_(18)(150 mm×4.6 mm, 5 μm). The flow rate was set at 1.0 mL/min. Fluorescence detection was performed at an excitation wavelength of 470 nm and an emission wavelength of 530 nm. The mobile phase consisted of a mixture of methanol and 0.02 M sodium dihydrogen phosphate(pH = 3.0, 60:40, v/v). The average extraction recovery of lisinopril and fluvoxamine(internal standard) was >85%. The method exhibited a linear calibration curve over the concentration range of 1–1000 ng/mL with a correlation coefficient(r^2) of ≥0.98 and a limit of quantification(LOQ) equal to 2 ng/mL. The within-run and between-run precisions were satisfactory with an RSD of 3.8%–13.7%(accuracy: from 95.0% to 96.4%) and 4.273%–14.3%(accuracy: from 94.4% to 98.5%), respectively.
基金supported by the Fundamental Research Funds for the Central Universities
文摘Er3＋-Yb3＋ codoped oxy-fluoro-tungstosilicate glasses with infrared-to-visible frequency upconversion luminescence were prepared by melting quenching in air.The effects of Er3＋ doping on the optical properties of the samples were measured by means of techniques such as optical absorption spectra and photoluminescence spectra.The results showed that intense green and red signals centered at 546 and 665 nm,corresponding to the 4S3/2 → 4I15/2 and 4F9/2 → 4I15/2 transitions of Er3＋ by a multiphoton stepwise phonon-assisted excited-state absorption process,respectively,were simultaneously observed by exciting the samples with a diode laser operating at 980 nm at room temperature.The upconversion process was found very sensitive to Er3＋ content at a constant Yb2O3 content of 5 mol.%.With the increase of Er3＋ content from 0.5% to 1.5%,the upconversion intensity increased gradually.Further increasing of Er3＋ content to 3.0% resulted in a significant fluorescence quenching.Moreover,the possible upconversion mechanisms were discussed based on the energy-matching conditions and the quadratic dependence on excitation power.
基金Tshe prOject!(39770469) supported by the National Natural Science Foundation of China.
文摘A rapid and simple method is presented for determining β-N-oxalyl-α. β- diaminopropionic acid (β -ODAP) and its much less toxic α -isomer (α -ODAP) in Lathyrus sativus. Seed and foliage extracts of Lathyrus sativus were treated with 1-fluoro-2,4-dinitrobenzene (FDNB) and a reversed-phase high-performance liquid chromatographic method for the separation of the derivatives in the pmol range is reported.
基金The project is supported by Natural Science Foundation of Shandong.
文摘In this paper, we report an improved method for preparing 2--alkoxy 5 fluoro--3H --4--pyrimidone from 2--chloro--5--fluoro--3H--4--pyrimidone and sodium alkoxide under normal pressure at reflux temperature. Some new compounds were synthesized in higher yield by this method.
文摘The purpose of this paper is to investigate the hydrophobic and mechanical behavior of the fluoro-carbon film on the composite.Fluoro-carbon films were fabricated on C/C and C/SiC composite by microwave ECR chemical vapor deposition combined with plasma source ion implantation technology (PSII).The films were investigated in terms of the surface morphology,chemical composition,hydrophobic behavior and mechanical properties.The hydrophobic property was determined by means of contact angle measurements,chemical bond structure was analyzed by fourier-transform infrared spectrum,and critical loading were measured by micro-scratch.The results showed that the fluorine presented mainly in the forms of CF2 group and C=CFx (x=1,2) in the film,the addition of fluorine to the carbon film had a critical influence on the hydrophobicity.Atomic force microscopy (AFM) were used for investigating the effect of surface morphology and roughness on hydrophobicity,it showed that fluoro-carbon films with appropriate surface morphology and roughness could achieve excellent hydrophobicity.
基金supported by Young Science Fund of Key Laboratory of Advanced Textile Materials and Manufacturing Technology (Zhejiang Sci-Tech. University),Ministry of Education
文摘The title compound VII, 2-fluoro-4-methyl-3-oxo-4-aza-5α-androst-1-ene-17β-carboxylic acid methyl ester （C21H30FNO3, Mr = 363.46）, was prepared through a seven-step reaction from pregnenolone, and characterized by elemental and single-crystal X-ray diffraction analyses as well as IR, MS and 1H-NMR spectra. It is of monoclinic system, space group P21/c with a = 6.3882（7）, b = 9.9033（11）, c = 15.4925（17） , β = 91.923（2）°, V = 979.57（19） 3, Z = 2, Dc = 1.232 mg/m3, μ = 0.088 mm-1, F（000）= 392, R = 0.0465, wR = 0.0989 and λ（MoKα） = 0.71073 . The structure indicates that the four cycles （A： C（1）–C（2）–C（3）–N（1）–C（5）–C（10）, B： C（5）–C（6）–C（7）– C（8）–C（9）–C（10）, C： C（8）–C（14）–C（13）–C（12）–C（11）–C（9）, D： C（14）–C（15）–C（16）–C（17）–C（13）） are in chairand trans-configurations. The results of crystal structure determination show that there exist weak intra-molecular hydrogen bonds, resulting in a two-dimensional supramolecular frame-work of the title compound.
