检索结果-南通市图书馆

Improved reversed phase liquid chromatographic method with pulsed electrochemical detection for tobramycin in bulk and pharmaceutical formulation

在线全文

学校读者我要写书评

暂无评论

Journal of Pharmaceutical Analysis 2013年第3期3卷 161-167页

作者： Vicky Manyanga Ehab Elkady jos hoogmartens Erwin Adams Laboratory for Pharmaceutical Analysis Faculteit Farmaceutische Wetenschappen KU LeuvenO&N2 PB 923 Herestraat 49 B-3000 Leuven Belgium Pharmaceutical Chemistry Department Faculty of Pharmacy Cairo University Kasr El-Aini St.Cairo 11562 Egypt

Tobramycin is one of the aminoglycoside antibiotics that lack a UV absorbing chromophore. However, the application of pulsed electrochemical detection （PED） has been used successfully for the analysis of this and similar antibiotics. This work describes an improved liquid chromatographic （LC） method combined with PED, which is able to separate much more impurities than before. Using a Discovery C-18 RP column （250 mm × 4.6 mm i.d., 5 μm）, isocratic elution was carried out with a mobile phase, containing sodium sulfate （35 g/L）, sodium octanesulphonic acid （1 g/L）, tetrahydrofuran （14mL/L） and 0.2 M phosphate buffer pH 3.0 （50 mL/L）. Using these experimental conditions, the limit of quantification （LOQ, S/N= 10） was 5 ng. The linearity was examined in the range LOQ-60 μg/mL and the coefficient of determination was 0.998. The method also proved to be repeatable and the recovery was close to 100%. The influence of the different chromatographic parameters on the separation was investigated by means of an experimental design. The proposed method is useful in quality control of tobramycin drug substances and drug products.

关键词： Liquidchromatography-Pulsed electrochemicaldetection Tobramycin Aminoglycosideantibiotics

色谱柱分类数据库用于指导天然药物化学对照品色谱纯度测定时色谱柱理性选择（英文）

在线全文

学校读者我要写书评

暂无评论

色谱 2017年第2期35卷 196-202页

作者：王明娟戴忠马双成金红宇 hoogmartens jos ADAMS Erwin 中国食品药品检定研究院中药民族药检定所北京100050 鲁汶大学药物分析实验室

由于中药化学对照品多数来源于动植物药材,很容易混有结构类似物,故有机杂质测定是可能影响其化学对照品赋值准确性的关键风险因素。中药化学对照品的有机杂质测定通常采用药典收载或文献报道的高效液相色谱法,这些方法通常仅规定"以十... 详细信息

由于中药化学对照品多数来源于动植物药材,很容易混有结构类似物,故有机杂质测定是可能影响其化学对照品赋值准确性的关键风险因素。中药化学对照品的有机杂质测定通常采用药典收载或文献报道的高效液相色谱法,这些方法通常仅规定"以十八烷基硅烷键合硅胶为填充剂",无适宜色谱柱的品牌信息,或者实验室无文献所用的色谱柱品牌,而目前市场上已有800多种品牌的C18柱,生产工艺的不同导致不同品牌C18柱的选择性有差异,甚至差异显著。这很容易出现由于色谱柱选择不适宜而导致测定结果不准确的风险。该文采用国外色谱柱分类数据库指导对照品纯度考察时色谱柱的理性选择,尽可能减少色谱柱盲选可能导致的纯度结果不准确的风险。首先,用数据库挑选2根选择性差异显著的色谱柱(选择性因子F≥6)进行平行实验,以尽可能反映采用不同品牌色谱柱可能出现的分离效果差异。如果这2根色谱柱的分离效果及纯度测定结果无显著性差异,则可以交叉验证该对照品纯度测定的准确性。否则需要从数据库中选择另外1根与之前试验中分离效果更好、选择性相似的色谱柱进行纯度结果验证。在N-反式-p-对香豆酰基酪胺和表儿茶素没食子酸酯首批对照品的纯度考察中,使用了上述策略并验证了其有效性和科学性,计划推广应用至更多的中药化学对照品,特别当其可能含碱性或弱酸性化合物时,更应该尝试采用本文推荐的色谱柱选择策略交叉验证其纯度测定结果的准确性。

关键词：中药化学对照品色谱纯度色谱柱理性选择策略色谱柱分类数据库 N-反式-P-对香豆酰基酪胺表儿茶素没食子酸酯

Facilitated column selection in the separation of acetylspiramycin components using a simple column classification system

在线全文

学校读者我要写书评

暂无评论

Journal of Chinese Pharmaceutical Sciences 2011年第6期20卷 572-577页

作者：王明娟郑超胡昌勤金少鸿 hoogmartens jos VanSchepdael Ann Adams Erwin 中国食品药品检定研究院北京100050 鲁汶大学药物分析实验室重庆大学生物工程学院四川重庆400030

Acetylspiramycin（ASPM）,a 16-membered basic macrolide antibiotic,is the acetylated derivative of *** addition to the four main components,more than seventy minor components could be present in ***,it is a challenge to obtain a baseline separation of ASPM ***,in some cases it was found that the results obtained by different brands of C_（18） columns were significantly different,indicating the necessity of a rational column selection for the separation of ASPM *** this paper,we attempted to facilitate column selection for the analysis of ASPM using the database of the column characterization system established by Leuven *** the CAPCELL PAK MG C_（18）（250 mm×4.6 mm,5μm） as the reference column,three groups of columns（F2 group：similar selectivity;2F6：intermediate ranked group;F6 group： different selectivity,compared to the reference column） were selected,and their performances in the separation of ASPM components were evaluated under the chromatographic conditions described in Chinese Pharmacopoeia monograph.A good relationship was demonstrated between the ranking of columns and their selectivity in the separation of ASPM components,indicating the column classification system established by Leuven University was a helpful tool in the selection of suitable columns for the analysis of ASPM,a complex mixture of basic compounds.

关键词： Acetylspiramycin Semi-synthetic antibiotic Column selection Column characterization system

甲硝唑光降解杂质的研究及对药典有关物质方法的优化建议

在线全文

学校读者我要写书评

暂无评论

药物分析杂志 2022年第9期42卷 1667-1674页

作者：陈美玲许红霞袁伟峰赵隋红李雪朱兰新谌宗永刘宇晶马昂王明娟 hoogmartens jos ADAMS Erwin 北京阳光诺和药物研究股份有限公司北京102200 鲁汶大学药物分析实验室鲁汶B3000

目的:对采用现有各国药典中甲硝唑有关物质方法考察甲硝唑强光照射影响因素试验出现的物料不平衡(甲硝唑降解程度明显高于有关物质增长幅度)的原因进行调查。方法:用液相色谱-二极管阵列检测-串联质谱法(LC PDA-MS)对强光破坏的甲硝唑... 详细信息

目的:对采用现有各国药典中甲硝唑有关物质方法考察甲硝唑强光照射影响因素试验出现的物料不平衡(甲硝唑降解程度明显高于有关物质增长幅度)的原因进行调查。方法:用液相色谱-二极管阵列检测-串联质谱法(LC PDA-MS)对强光破坏的甲硝唑水溶液及其复方阴道洗剂的光降解产物进行定性鉴别和紫外光谱研究;用推导结构(N-(2-羟乙基)-5-甲基-l, 2,4-(口恶)二唑-3-甲酰胺)的杂质对照品,通过与甲硝唑光降解杂质保留时间和提取PDA光谱的一致性对比,及与甲硝唑氢谱的平行比较,对推导的甲硝唑光降解杂质结构进行确证;根据定性和光谱研究结果,依据现有药典方法优化了能同时检测该光降解杂质的方法并进行全面方法学验证。结果:甲硝唑在溶液、紫外光照条件下容易发生光降解,该杂质最大吸收约在230 nm,而在各论项下有关物质方法中设置的315/319 nm处吸收强度很弱。已上市甲硝唑注射液(需要缓慢输液)在室温光照条件下放置48 h或在5 000 lx条件下处理2 d和5 d后,光降解产物的量从“未检出”快速增加至0.15%、0.36%和0.88%,均超过本品的鉴定限(0.10%)和界定限(0.15%)。用230 nm检测并引入梯度洗脱、在各论项方法基础上优化建立的方法,能同时检测该光降解杂质和甲硝唑特定杂质2-甲基-5-硝基咪唑,方法的专属性、灵敏度、精密度、溶液的稳定性等指标均满足要求。结论:通过对甲硝唑光降解杂质的结构鉴定和光谱特征研究,揭示了采用现有药典检查方法考察甲硝唑光破坏样品出现的物料不平衡原因;建立了能同时控制该光降解杂质和甲硝唑现有特定杂质的优化方法;甲硝唑注射液慢速输液过程存在较大的光降解风险,需引起关注。

关键词：甲硝唑光降解风险评估结构鉴定串联质谱氢谱定量检测方法优化

Mitochondria–cGAS–STING axis is a potential therapeutic target for senescence-dependent inflammaging-associated neurodegeneration

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第3期20卷 805-807页

作者： joséM.Izquierdo Centro de Biología Molecular Severo Ochoa(CBM) Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid(CSIC-UAM)MadridSpain

The word “senescence” comes from the Latin senescens, meaning “to begin to age”, and is characterized by a long-lasting but reversible block in proliferation, resulting from stress-induced cell cycle arrest of pre... 详细信息

关键词： Latin potential lasting

The emerging role of mesenchymal stem cell-derived extracellular vesicles to ameliorate hippocampal NLRP3 inflammation induced by binge-like ethanol treatment in adolescence

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第4期20卷 1153-1163页

作者： Susana Mellado María joséMorillo-Bargues Carla Perpiñá-Clérigues Francisco García-García Victoria Moreno-Manzano Consuelo Guerri María Pascual Department of Physiology School of Medicine and DentistryUniversity of ValenciaValenciaSpain Bioinformatics and Biostatistics Unit Príncipe Felipe Research CenterValenciaSpain Neuronal and Tissue Regeneration Laboratory Príncipe Felipe Research CenterValenciaSpain

Our previous studies have reported that activation of the NLRP3(NOD-,LRR-and pyrin domain-containing protein 3)-inflammasome complex in ethanol-treated astrocytes and chronic alcohol-fed mice could be associated with neuroinflammation and brain *** stem cell-derived extracellular vesicles(MSC-EVs)have been shown to restore the neuroinflammatory response,along with myelin and synaptic structural alterations in the prefrontal cortex,and alleviate cognitive and memory dysfunctions induced by binge-like ethanol treatment in adolescent *** the therapeutic role of the molecules contained in mesenchymal stem cell-derived extracellular vesicles,the present study analyzed whether the administration of mesenchymal stem cell-derived extracellular vesicles isolated from adipose tissue,which inhibited the activation of the NLRP3 inflammasome,was capable of reducing hippocampal neuroinflammation in adolescent mice treated with binge *** demonstrated that the administration of mesenchymal stem cell-derived extracellular vesicles ameliorated the activation of the hippocampal NLRP3 inflammasome complex and other NLRs inflammasomes(e.g.,pyrin domain-containing 1,caspase recruitment domain-containing 4,and absent in melanoma 2,as well as the alterations in inflammatory genes(interleukin-1β,interleukin-18,inducible nitric oxide synthase,nuclear factor-kappa B,monocyte chemoattractant protein-1,and C–X3–C motif chemokine ligand 1)and miRNAs(miR-21a-5p,miR-146a-5p,and miR-141-5p)induced by binge-like ethanol treatment in adolescent *** analysis further revealed the involvement of miR-21a-5p and miR-146a-5p with inflammatory target genes and NOD-like receptor signaling *** together,these findings provide novel evidence of the therapeutic potential of MSC-derived EVs to ameliorate the hippocampal neuroinflammatory response associated with NLRP3 inflammasome activation induced by binge drinking in adolescence.

关键词： adolescence binge-like ethanol treatment extracellular vesicles hippocampus mesenchymal stem cells neuroinflammation NOD-,LRR-and pyrin domain-containing protein 3(NLRP3)

Touristic urbanization and greening of coastal dune fields:A long-term assessment of a temperate sandy barrier of Argentina

在线全文

学校读者我要写书评

暂无评论

Journal of Geographical Sciences 2025年第1期 206-230页

作者： GARZO Pedro Andrés DADON josé Roberto ISLA Federico Ignacio Instituto de Investigaciones Marinas y Costeras (IIMyC-CONICET/UNMDP) Instituto de Geología de Costas y del Cuaternario Dr.Enrique J.Schnack (IGCC-CIC/UNMDP) Universidad de Buenos Aires Facultad de Arquitectura Dise?o y Urbanismo Centro de Investigaciones Gestión de Espacios Costeros (GEC-FADU/UBA) Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET)

Dune barrier systems represent highly sought-after coastal landscapes for tourism and urban development around the world. However, a century ago, they were considered hazardous environments due to their great dynamic nature. As a result, stabilization practices were considered necessary. The systematic introduction of fast-growing exotic trees helped stabilize the sand, making it easier for tourism urbanization to take place, but also leading to erosion processes. This paper aims to assess long-term changes in vegetation cover over a large temperate barrier in Argentina. This complex region includes urban resorts, afforestation zones, and protected areas. A GIS-based geospatial analysis was conducted using a large satellite database(> 350 images), and the future evolution of the vegetation was modeled. The results revealed two primary spatiotemporal patterns associated with a gradual expansion of vegetation cover, accompanied by a concurrent reduction in sandy areas. In 1986, the dune area comprised 75% more surface than vegetation, whereas in 2021, it represented 60% less than vegetation. Furthermore, the 2050 scenario suggests a potential 40% reduction of dunes in certain areas. It is necessary to enhance management actions aimed at maintaining dune mobility and ensuring local and regional sediment balance. Long-term management strategies must focus on restoring native plant communities and controlling invasive species, and avoiding new dune fixation initiatives based on the introduction of exotic species.

关键词：

Differential response of injured and healthy retinas to syngeneic and allogeneic transplantation of a clonal cell line of immortalized olfactory ensheathing glia:a double-edged sword

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第8期20卷 2395-2407页

作者： María Norte-Muñoz María Portela-Lomba Paloma Sobrado-Calvo Diana Simón Johnny Di Pierdomenico Alejandro Gallego-Ortega Mar Pérez joséMCabrera-Maqueda Javier Sierra Manuel Vidal-Sanz María Teresa Moreno-Flores Marta Agudo-Barriuso Grupo de Investigación Oftalmología Experimental Departamento de OftalmologíaOptometríaOtorrinolaringología y Anatomía PatológicaFacultad de MedicinaUniversidad de MurciaInstituto Murciano de Investigación Biosanitaria(IMIB)Campus de Ciencias de la SaludMurciaSpain Experimental Sciences Faculty Universidad Francisco de VitoriaPozuelo de AlarcónMadridSpain Anatomy Histology and Neuroscience DepartmentMedicine FacultyUniversidad Autónoma de MadridMadridSpain Center of Neuroimmunology Service of NeurologyLaboratory of Advanced Imaging in Neuroimmunological DiseasesHospital Clínic of BarcelonaInstitut d’Investigacions Biomèdiques August Pi i Sunyer(IDIBAPS)and Universitat de BarcelonaBarcelonaSpain Medicine Faculty Universidad Francisco de VitoriaPozuelo de AlarcónMadridSpain

Olfactory ensheathing glia promote axonal regeneration in the mammalian central nervous system,including retinal ganglion cell axonal growth through the injured optic ***,it is unknown whether olfactory ensheathing glia also have neuroprotective *** ensheathing glia express brain-derived neurotrophic factor,one of the best neuroprotectants for axotomized retinal ganglion ***,we aimed to investigate the neuroprotective capacity of olfactory ensheating glia after optic nerve *** ensheathing glia cells from an established rat immortalized clonal cell line,TEG3,were intravitreally injected in intact and axotomized retinas in syngeneic and allogeneic mode with or without microglial inhibition or immunosuppressive *** and gene expression analyses were *** bulb-derived primary olfactory ensheathing glia and TEG3 express major histocompatibility complex classⅡ*** and syngenically transplanted TEG3 cells survived in the vitreous for up to 21 days,forming an *** axotomized retinas,only the allogeneic TEG3 transplant rescued retinal ganglion cells at 7 days but not at 21 *** these retinas,microglial anatomical activation was higher than after optic nerve crush *** intact retinas,both transplants activated microglial cells and caused retinal ganglion cell death at 21 days,a loss that was higher after allotransplantation,triggered by pyroptosis and partially rescued by microglial inhibition or ***,neuroprotection of axotomized retinal ganglion cells did not improve with these *** different neuroprotective properties,different toxic effects,and different responses to microglial inhibitory treatments of olfactory ensheathing glia in the retina depending on the type of transplant highlight the importance of thorough preclinical studies to explore these variables.

关键词： cell therapy immune recognition major histocompatibility complex class II(MHCII) neuroprotection olfactory ensheathing glia retinal ganglion cells

Analysis of Viscous Heating in a Micro-Rocket Flow and Performance

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2008年第2期17卷 116-124页

作者： josé A.Moríigo josé Hermida Quesada Dept.of Space Programmes National Institute for Aerospace Technology Dept.of Aerodynamics and Propulsion National Institute for Aerospace Technology

Micro-rockets for propulsion of small spacecrafts exhibit significant differences with regard to their macroscale counterparts,mainly caused by the role of the viscous dissipation and heat transfer processes in the micron-sized *** goal of this work is to simulate the transient operation of a micro-rocket to investigate the effects of viscous heating on the flow and performance for four configurations of the expanding gas and wafer *** modelling follows a multiphysics approach that solves the fluid and solid regions fully coupled.A contin- uum-based description that incorporates the effects of gas rarefaction through the micro-nozzle,viscous dissipa- tion and heat transfer at the solid-gas interface is ***-equilibrium is addressed with the implementa- tion of a 2nd-order slip-model for the velocity and temperature at the *** results stress that solid-fluid cou- pling exerts a strong influence on the flowfield and performance as well as the effect of the wafer during the first instants of the transient in micro-rockets made of low and high thermal conductivity materials.

关键词： Micronozzles propulsion MEMS slip flow viscous heating