A sensitive and specific high performance liquid chromatography （HPLC） method was developed and validated for the simultaneous determination of metformin hydrochloride （HCI） in human plasma. The HPLC method consis...A sensitive and specific high performance liquid chromatography （HPLC） method was developed and validated for the simultaneous determination of metformin hydrochloride （HCI） in human plasma. The HPLC method consists of isocratic eluation with a mixture of 60% buffer （10 mM sodium dihyrogenphosphate-10 mM sodium dodecyl sulphate） and 40% acetonitrile with final pH 7.0 with flow rate of 1.0 mL/min on a Kromasil~ Akzo Nobel RP-18 （4.6 mm ID ~ 250 mm, 5 ~tm） column at an ambient temperature. Photo diode array detection was performed in program mode at 234 rim. The analyte and diazepam as internal standard （IS） were extracted from plasma using 10% trichloroacetic acid. The assay was linear over the therapeutic concentration range of 20-2,500 ng/mL for metformin HCI with correlation coefficient of r = 0.9999. Limit of quantitation was 20 ng/mL. The results obtained for intraJinter day accuracy and precision complied very well with the generally accepted criteria for bio-analytical assay. The method was applied to bioequivalence （BE） study of metformin HCI in healthy Indonesian volunteers after treatment with 750 mg XR metformin HCI. This BE study shows that the two formulations are equivalent so that they were therapeutically interchangeable for each other.展开更多
Photo Diode Array (PDA) has been successfully applied in HT-7 tokamak experiments. The PDA system is almost free of electromagnetic interference from the machine. The system is compact and inexpensive, and it is conve...Photo Diode Array (PDA) has been successfully applied in HT-7 tokamak experiments. The PDA system is almost free of electromagnetic interference from the machine. The system is compact and inexpensive, and it is convenient to be arranged in experiment. With the PDA system, the particle confinement time (τp) has been systematically investigated. The relations such as τp on the center-line-averaged electron density (ne), τp on plasma current (Ip), and τp, on the toroidal magnetic field (Bt) have been obtained. The particle confinement under the Ion Berstain Wave (IBW) Heating has also been measured and analyzed.展开更多
[目的]建立“染红食品”中苏丹红Ⅰ、Ⅱ、Ⅲ和Ⅳ残留量的高效液相色谱(HPLC)初筛、质谱确认分析方法。[方法]以Merck RP-18柱为分析柱,流动相:乙腈∶水=90∶10,Waters-2996二极管矩阵检测器(PDA)和FinniganLCQ Deca XP MAX质谱仪为检测...[目的]建立“染红食品”中苏丹红Ⅰ、Ⅱ、Ⅲ和Ⅳ残留量的高效液相色谱(HPLC)初筛、质谱确认分析方法。[方法]以Merck RP-18柱为分析柱,流动相:乙腈∶水=90∶10,Waters-2996二极管矩阵检测器(PDA)和FinniganLCQ Deca XP MAX质谱仪为检测器。[结果]回归方程和相关系数为:苏丹红Ⅰ:y=0.163104x+0.019217,r=0.99993;苏丹红Ⅱ:y=0.153674x-0.2212981,r=0.99993;苏丹红Ⅲ:y=0.305919x-5.0810264,r=0.9997;苏丹红Ⅳ:y=0.239273x-5.260669,r=0.9997。平均回收率(%):87.3、83.0、86.7和90.0。[结论]用HPLC-PDA-MS法检测食品中的苏丹红方法简便,重现性好,灵敏度高,定性准确,定量精确。展开更多
Objective Using optical imaging in brainstem slices, we studied evoked responses in the mouse cochlear (CN) and vestibular (VN) nuclei. Methods The use of optical imaging allowed us to visualize the spatiotemporal pat...Objective Using optical imaging in brainstem slices, we studied evoked responses in the mouse cochlear (CN) and vestibular (VN) nuclei. Methods The use of optical imaging allowed us to visualize the spatiotemporal patterns of excitatory propagation in the CN and VN. Optical recordings can differentiate excitatory propagation in the ventral CN(VCN) from that in the dorsal CN(DCN). Furthermore, we assessed the relative distribution of NMDA and non-NMDA receptors in these regions using the glutamate antagonists APV (NMDA receptor antagonist) and CNQX (non-NMDA receptor antagonist) in mouse brainstem slices during postnatal days 1 to 3. Results The average sensitivity to APV was 99.1% in the VCN, 76.0% in the DCN and 64.9% in the VN. The average sensitivity to CNQX was 0.9% in the VCN, 24.0% in the DCN and 35.1% in the VN. These results indicate that the effect of APV dominated in the VCN, while both APV and CNQX were effective antagonists in the DCN and VN. In the VN, the distribution of APV-and CNQX-sensitive cells was almost completely uniform. However, in the DCN the distribution of APV-and CNQX-sensitive cells was highly complex. The area that was more sensitive to CNQX was located in the superficial layer of the DCN while the area with a higher sensitivity to APV was located progressively in the deep layer. Conclusion This optical recording data suggests that there is a differential distribution of NMDA and non-NMDA receptor mediated neurotransmission in the VCN, DCN and VN.展开更多
文摘A sensitive and specific high performance liquid chromatography （HPLC） method was developed and validated for the simultaneous determination of metformin hydrochloride （HCI） in human plasma. The HPLC method consists of isocratic eluation with a mixture of 60% buffer （10 mM sodium dihyrogenphosphate-10 mM sodium dodecyl sulphate） and 40% acetonitrile with final pH 7.0 with flow rate of 1.0 mL/min on a Kromasil~ Akzo Nobel RP-18 （4.6 mm ID ~ 250 mm, 5 ~tm） column at an ambient temperature. Photo diode array detection was performed in program mode at 234 rim. The analyte and diazepam as internal standard （IS） were extracted from plasma using 10% trichloroacetic acid. The assay was linear over the therapeutic concentration range of 20-2,500 ng/mL for metformin HCI with correlation coefficient of r = 0.9999. Limit of quantitation was 20 ng/mL. The results obtained for intraJinter day accuracy and precision complied very well with the generally accepted criteria for bio-analytical assay. The method was applied to bioequivalence （BE） study of metformin HCI in healthy Indonesian volunteers after treatment with 750 mg XR metformin HCI. This BE study shows that the two formulations are equivalent so that they were therapeutically interchangeable for each other.
文摘Photo Diode Array (PDA) has been successfully applied in HT-7 tokamak experiments. The PDA system is almost free of electromagnetic interference from the machine. The system is compact and inexpensive, and it is convenient to be arranged in experiment. With the PDA system, the particle confinement time (τp) has been systematically investigated. The relations such as τp on the center-line-averaged electron density (ne), τp on plasma current (Ip), and τp, on the toroidal magnetic field (Bt) have been obtained. The particle confinement under the Ion Berstain Wave (IBW) Heating has also been measured and analyzed.
文摘[目的]建立“染红食品”中苏丹红Ⅰ、Ⅱ、Ⅲ和Ⅳ残留量的高效液相色谱(HPLC)初筛、质谱确认分析方法。[方法]以Merck RP-18柱为分析柱,流动相:乙腈∶水=90∶10,Waters-2996二极管矩阵检测器(PDA)和FinniganLCQ Deca XP MAX质谱仪为检测器。[结果]回归方程和相关系数为:苏丹红Ⅰ:y=0.163104x+0.019217,r=0.99993;苏丹红Ⅱ:y=0.153674x-0.2212981,r=0.99993;苏丹红Ⅲ:y=0.305919x-5.0810264,r=0.9997;苏丹红Ⅳ:y=0.239273x-5.260669,r=0.9997。平均回收率(%):87.3、83.0、86.7和90.0。[结论]用HPLC-PDA-MS法检测食品中的苏丹红方法简便,重现性好,灵敏度高,定性准确,定量精确。
基金supported by a grant-in-aid for scientific research to M.A.(No. 12771000), to T.Y. (No. 10671622) and to T.D. (No. 11771023) from the Ministry of Education, Japansupported in part by grants from the National Natural Science Fund of China (No. 30871398, 30730040, 30571017)Hi-Tech Research and Development Program of China (863) (#2007AA 02Z150)
文摘Objective Using optical imaging in brainstem slices, we studied evoked responses in the mouse cochlear (CN) and vestibular (VN) nuclei. Methods The use of optical imaging allowed us to visualize the spatiotemporal patterns of excitatory propagation in the CN and VN. Optical recordings can differentiate excitatory propagation in the ventral CN(VCN) from that in the dorsal CN(DCN). Furthermore, we assessed the relative distribution of NMDA and non-NMDA receptors in these regions using the glutamate antagonists APV (NMDA receptor antagonist) and CNQX (non-NMDA receptor antagonist) in mouse brainstem slices during postnatal days 1 to 3. Results The average sensitivity to APV was 99.1% in the VCN, 76.0% in the DCN and 64.9% in the VN. The average sensitivity to CNQX was 0.9% in the VCN, 24.0% in the DCN and 35.1% in the VN. These results indicate that the effect of APV dominated in the VCN, while both APV and CNQX were effective antagonists in the DCN and VN. In the VN, the distribution of APV-and CNQX-sensitive cells was almost completely uniform. However, in the DCN the distribution of APV-and CNQX-sensitive cells was highly complex. The area that was more sensitive to CNQX was located in the superficial layer of the DCN while the area with a higher sensitivity to APV was located progressively in the deep layer. Conclusion This optical recording data suggests that there is a differential distribution of NMDA and non-NMDA receptor mediated neurotransmission in the VCN, DCN and VN.
