地昔尼尔乳剂的制备及其HPLC测定方法的建立

为制备地昔尼尔乳剂并建立其质量浓度的测定方法,以稳定常数和离心稳定性作为乳剂稳定性评价指标,采用单因素试验和正交设计试验法考察处方因素和工艺因素对乳剂稳定性的影响,以筛选出乳剂的最优处方和制备工艺;采用高效液相色谱法(HPLC)测定乳剂的药物质量浓度。结果显示,地昔尼尔乳剂的最优处方为地昔尼尔50g/L、乳化剂70mL/L、油相125mL/L、助乳化剂160mL/L、稳定剂为3.5g/L;地昔尼尔乳剂的制备方法为乳化温度50℃,20 000r/min高速搅拌10min。建立的HPLC色谱条件为色谱柱X Bridge C18(4.6mm×250mm,5μm),流动相乙腈与水(6mL/L三乙胺+2mL/L甲酸)的体积比为10∶90,流速0.8mL/min,柱温30℃,紫外检测波长267nm,进样体积20μL。在10~100μg/mL的质量浓度范围内,峰面积与药物浓度呈良好线性关系(r2=0.999 9,n=7),回归方程为y=148.01x+91.629。精密度试验相对标准偏差均小于2%,在80%、100%和120%3个添加水平时,平均回收率为98.36%,精密度、回收率均符合要求。定量限和检测限分别为10ng/mL和20ng/mL,测得3批地昔尼尔乳剂的平均质量浓度为49.29mg/mL,为标示量的98.57%。结果表明,该处方合理、制备工艺可靠,所建立的高效液相色谱法可用于地昔尼尔乳剂的检测。     

用响应面法优化四黄止痢复方中药提取工艺

为制备四黄止痢复方中药并建立其高效液相色谱(HPLC)检测方法,在单因素试验的基础上,以浸渍时间、料液比[质量(g)体积(mL)比]、甲醇体积分数为自变量,黄芩苷、盐酸小檗碱质量浓度及干膏率综合评分为因变量,采用HPLC法测定其质量浓度,响应面法进行试验设计、建立数学模型,并进行预测分析。结果显示,四黄止痢复方中药的最佳提取工艺为浸渍时间146 min、料液比1︰333、甲醇体积分数80%。建立的HPLC色谱条件为色谱柱Kromasil C18柱(250 mm×4.6 mm,5 m),流动相甲醇(A)-0.1%磷酸水(B)梯度洗脱,检测波长278 nm,流速1.0 mL/min,进样体积10 L,柱温25℃。结果表明,用响应面法优化的四黄止痢复方中药提取工艺,方法简单,精密度高;所建立的HPLC法可用于四黄止痢复方中药的检测。     

用高效液相色谱法测定喹烯酮原料药及其预混剂的含量

用YMG-H35C18色谱柱,以甲醇水(8020)为流动相,于紫外波长229 nm处,采用内标法测定喹烯酮及其预混剂中喹烯酮的含量.测定结果,喹烯酮浓度(x)与其峰高和内标物峰高之比(Y)呈良好的线性关系,线性方程为y=0.0546x-0.0003,r=0.9999,喹烯酮在5～50μg/mL范围内呈良好的线性关系,在上述色谱条件下其最低检测浓度为1.25μg/mL,日内与日间变异系数分别为0.37%和0.49%.     

绵羊血浆中氟甲喹及其代谢产物7-羟基氟甲喹浓度的RP-HPLC测定

利用C8色谱柱(4.6 mm×150 mm,5μm),以V(乙腈)∶V(15 mmol/L KH2PO4)缓冲液=39∶61为流动相,在320 nm紫外光下,利用反相高效液相色谱法(RP-HPLC)测定了绵羊血浆中氟甲喹及其代谢产物7-羟基氟甲喹的浓度。结果显示,氟甲喹和7-羟基氟甲喹分别在20~10 000 ng/mL和20~500ng/mL范围内线性关系良好(r=0.999和r=0.998),平均绝对回收率分别为84.3%±6.7%和67.5%±5.6%,日内与日间精密度均小于8.3%,最低检测限均为10 ng/mL;内源性物质不干扰测定。表明,RP-HPLC的工作曲线稳定,灵敏度高,操作步骤简单,可用于绵羊血浆中氟甲喹及其代谢产物7-羟基氟甲喹浓度的测定和药动学考察。     

猪和鸡血浆中硫酸黏杆菌素浓度的高效液相色谱-荧光检测

采用甲醇-100g/L三氯乙酸混合液(二者体积比为50:50)提取血浆中的硫酸黏杆菌素,用邻苯二甲醛进行柱前衍生。荧光检测,激发波长344nm,发射波长436nm。流动相为V乙腈:V0.01mol/L磷酸缓冲液=68:32,流速为1.4mL/min。猪、鸡血浆中硫酸黏杆菌素浓度为0.1～4μg/mL时,硫酸黏杆菌素与其峰面积之间存在良好的线性关系(r2=0.997),最低定量限为0.1μg/mL。血浆中添加0.1、0.5、2.0μg/mL浓度的硫酸黏杆菌素,其回收率70%,变异系数均10%。结果表明,建立的猪和鸡血浆中硫酸黏杆菌素浓度的高效液相色谱-荧光检测方法重复性好、灵敏度高、操作简便,可用于猪和鸡血浆中硫酸黏杆菌素浓度的测定。     

高效液相色谱法同时检测水产品中7种四环素类抗生素残留的研究

采用Inertsil C8-3(5μm,250 mm×4.0 mm i.d.)反相色谱柱,以pH 4.0的EDTA-McIlvaine缓冲溶液为提取溶液,以HLB固相萃取柱为净化柱,以甲醇 乙腈 0.01 mol/L三氟乙酸为流动相(梯度洗脱),流速为1.5 mL/min,检测波长为350 nm,进样量100μL,建立了同时检测水产品中四环素、金霉素、土霉素、强力霉素、去甲基金霉素、甲烯土霉素和二甲胺四环素等7种四环素类抗生素残留的液相色谱法。该方法的检出限为1.5~5.0μg/kg,测定低限为50μg/kg,线性范围为50~1 000μg/kg,加标回收率为75.2%~100.6%,相对标准偏差为2.19%~10.56%。上述结果表明,该方法具有灵敏、准确、简便、快速等优点,适用于水产品中上述7种四环素类抗生素残留的同时检测。     

反相高效液相色谱法测定猪血清中的盐酸环丙沙星

建立反相高效液相色谱(RP-HPLC)法测定猪血清中环丙沙星(CPFX)浓度的方法,采用Waters HPLC系统,Nova-pak ODS柱,以乙腈(含三乙胺的磷酸盐缓冲液)为流动相,检测的波长为278nm,血清中CPFX用二氯甲烷萃取.0.01～10.24μg/mL环丙沙星水溶液浓度与色谱峰高呈良好线性关系(r=0.9997),平均回收率大于80%,批内、批间变异系数(CV)分别小于5%和10%(n=6).RP-HPLC法简便、快速、灵敏、准确,适用于CPFX在猪体内的药物动力学和药物残留的研究.     

一种测定氟尼辛葡甲胺含量新方法的建立

为了建立高效液相色谱法测定复方庆大霉素注射液中氟尼辛葡甲胺的含量,选用色谱柱Thermo Accucore C18 100×2.1 mm,2.6 m;流动相A为0.1%三氟乙酸水溶液,B为乙腈;流动相A与B之间的比例为9∶1;用DAD检测器检测波长为254 nm;流速0.4 mL/min;柱温30℃,进样体积2.00 L。化合物的色谱图采集和积分由软件Chemstation进行处理。用内标法计算待测样品中氟尼辛葡甲胺的含量。结果,氟尼辛葡甲胺在该色谱条件下具有良好的系统适应性。回归方程的结果如下:y=2.545 35x+0.020 695 2。线性相关系数为r=0.999 91,氟尼辛葡甲胺的浓度在31.25～1000 g/mL范围内线性相关性良好。平均回收率在102.71%～108.33%之间,相对标准偏差为2.35%,小于3%。精密度试验中所有相对标准偏差都低于5%。复方庆大霉素注射液中氟尼辛葡甲胺的平均含量为212.8 g/mL,为标示量的106.4%,符合《中华人民共和国兽药典一部》的规定。上述结果表明,该方法可用于复方庆大霉素注射液中氟尼辛葡甲胺含量的测定。     

鱼肌肉中氟苯尼考和氟苯尼考胺残留的高效液相色谱检测

建立了同时检测鱼肌肉组织中氟苯尼考和氟苯尼考胺残留的高效液相色谱检测法。以水和丙酮为提取溶液,Oasis MCX固相萃取柱为净化柱,采用Inertsil ODS—3(5μm,250 mm×4.6 mm i.d.)反相色谱柱,以A液(0.02 mol/L庚烷磺酸-钠0.025 mol/L磷酸钠溶液,二者体积比68∶32,pH3.85)与B液(含1 mL/L三乙胺的甲醇溶液)为流动相,梯度洗脱,紫外检测器225 nm处检测。结果显示,在10~1 000μg/kg浓度范围内,线性关系良好;加标回收率为75.9%~82.8%,日内变异系数为2.1%~5.8%,日间变异系数为4.7%~7.7%;氟苯尼考胺和氟苯尼考的检测限分别为5μg/kg和10μg/kg,定量限分别为10μg/kg和20μg/kg。结果表明,所建立的检测方法具有灵敏、准确、简便、快速的特点,适于同时检测鱼肌肉中氟苯尼考和氟苯尼考胺的残留。     

动物组织黏菌素残留柱前衍生化高效液相色谱-荧光检测方法的建立

以100 mL/L的三氯乙酸-甲醇(体积比为50:50)混合液提取组织中的药物,采用C18固相萃取小柱净化,使用氯甲酸芴甲酯.在0.1 mol/L的硼酸缓冲液(pH10)中进行柱前衍生化,反应15 min,直接进样.荧光检测.激发波长为260 nm,发射波长为315 nm,流动相为V乙睛:V四氢吹喃:V水=87:4:13,流速为1 mL/min.动物组织中黏菌素含量为0.05～1.00 ug/g时,黏菌素的含量与其峰面积之间存在良好的线性关系(r2＞0.990),在猪、鸡的肌肉、肝、肾组织中按0.05、0.15、1.00 ug/g 3个添加水平做黏菌素的回收率试验,其回收率≥80%,变异系数≤12%.结果表明,该方法重复性好,灵敏度高,简便,可用于动物组织中黏菌素残留的检测.     

The Development of EU-Russian Relations

The EU＇s strategy for Russia since the end of the cold war has to a large extent failed, and the direct consequences are the currently deadlocked EU-Russia relationship. There are three reasons for this： the EU and Russia＇s respective strength and status relative to each other have been changing since the beginning of this century; the EU＇s strategy towards Russia has been more fragmenting in recently years; and the American factor. The EU-Russia relations could continue to be in poor shape in the years to come, and it is very likely sometimes even further worsening. But the two sides would refrain from extreme measures and prevent their relations from sliding into real cold war.     

Young American China Watchers＇ Views on China

In this paper, the author has made a thorough study over the new generation of American China Watchers. Most of the pages are devoted to a detailed comparison between the old generation and the young generation of American China Watchers regarding to their background, education, and views over China. At the end of the paper, the author also gives some policy suggestions for both the Chinese and U.S. government based on the findings in this study.     

China＇s Rise vs. International Order Evolution

A heated debate over the rise of China has been going on unabated in the international community for nearly two decades. However, with the elapse of time, the initial divergence of views in the mainstream opinion has gradually diminished and the gap in China policy among nations has likewise narrowed down. Instead, reason and a realistic approach have eventually taken center stare.     

The Balance Between Coercion and Accommodation

1. Introduction
On the morning of April 1st, 2001, a U.S. EP-3 surveillance aircraft was conducting an intelligence flight along the Chinese territorial border in the airspace south-east of China＇s Hainan Island. Two Chinese fighter jets intercepted the spy plane and followed its flight, as is considered ordinary international practice. For reasons unknown, the EP-3 airplane made a sudden maneuver and crashed into one of the Chinese planes. The Chinese plane dropped into the sea, the pilot missing. The U.S. spy plane was also severely damaged. It intruded into Chinese territorial space and landed on Hainan Island without official permission from the Chinese side. After landing, the spy plane and 24 crew on board were detained by the Chinese authorities. This air collision episode was the first of its kind in the China-U.S. relations and an urgent diplomatic crisis ensued.     

The U. S. Policy toward DPRK: Opportunities and Constraints

布什政府上台以来,始终未能阻止朝鲜拥核步伐.朝核试后,美对朝政策有了新的调整,六方会谈得以复会.但美朝双方受各自国家利益和政策目标的限制,在朝鲜半岛无核化问题上的尖锐分歧难以解决,朝核危机仍存在再度升级的可能.     

Marxist Philosophy vs. International Relations Research in China

This article argues for the confirmation of Marxist philosophy as the ideology that guides international relations （IR） studies in China. Justification comes through the following points. According to Marxism, correct theoretical guidance serves as the prerequisite for correct practice. Marxist philosophy embodies, by nature, righteousness, in opposition to political hegemony. Accordingly, practice under its guidance represents fruitful revolutionary realism. Finally, advanced studies of international relations in this country cannot be separated from philosophical thinking. Using these arguments as background, this article specifically advocates materialism, patriotism, and service to the people as the corner-stone of China＇s IR theory building.     

Excavating Concealed Tradeoffs: How Russians Watch the News

Citizens in democracies are expected to make better decisions if they understand policy tradeoffs. However, politicians rarely have incentives to communicate them; citizens are uncomfortable choosing among valued outcomes; and devising a common metric is difficult. It is not surprising that in the United States the environment provides relatively little cuing or priming of tradeoffs in television news. Russian citizens, on the other hand, face a media environment in which tradeoff cuing is intentionally suppressed by owners' agendas, yet viewers detect concealed tradeoffs even in the absence of tradeoff priming and viewpoint diversity. Analysis of discourse among ordinary Russians in 16 focus groups convened in four cities, differentiated by political reform and media market environments, showed that when watching news in which tradeoffs are thoroughly concealed, viewers challenge stories by offering a broad spectrum of uncued tradeoffs. Tradeoffs come from diverse policy domains and represent a range of cognitive strategies, some of which are considerably more abstract than others and link elements of their observations and assumptions (together with what they can extract from the stories) into complex reasoning outcomes.     

The U.S. Global Strategy as Seen from the Debate in the Primary Election

There may be more than one year to go before the 2008 U.S. presidential election, but the primary election of the two parties has already begun ahead of time. Both the Democratic and Republican candidates for the     

中国需要构建怎样的周边(英文)

正The new central leadership has highlighted the strategic importance of better relations with neighboring countries and the construction of a solid foundation for China’s neighborhood strategy so as to create favorable conditions for Chinese development.1China is strengthening top-level strategy in foreign relations,focusing on global-level relations and staying committed to relations     

中巴关系的发展及其认识误区（英文）

China and Brazil established a strategic partnership in 1993. The bilateral ties have seen rapid development in almost all areas. However, there are eight myths surrounding the China-Brazil relations. These myths are the result of a lack of mutual understanding as well as the misconceptions result misconceptions of the western observers and media. These misunderstandings have of have jeopardized images of the China-Brazil relations and also hindered further development of their bilateral relationship.