Analysis of nitrite in adulterated urine samples by capillary electrophoresis

A simple method for analyzing nitrite in urine has been developed to confirm and quantify the amount of nitrite in potentially adulterated urine samples. The method involved separation of nitrite by capillary electrophoresis and direct UV detection at 214 nm. Separation was performed using a bare fused silica capillary and a 25 mM phosphate run buffer at a pH of 7.5. Sample preparation consisted of diluting the urine samples 1:20 with run buffer and internal standard, and centrifuging for 5 min at 2500 rpm. The sample was hydrodynamically injected, then separated using -25 kV with the column maintained at 35 degrees C. The method had upper and lower limits of linearity of 1500 and 80 microg/mL nitrite, respectively, and a limit of detection of 20 microg/mL. The method was evaluated using the National Committee for Clinical Laboratory Standards (NCCLS) protocol (Document EP10-A2), and validated using controls, standards, and authentic urine samples. Ten anions, ClO-, CrO4(-2), NO3-, HCO3-, I-, CH3COO-, F-, SO4-, S2O8(-2), and Cl-, were tested for potential interference with the assay. Interferences with quantitation were noted for only CrO4(-2) and S2O8(-2). High concentrations of Cl- interfered with the chromatography. The method had acceptable accuracy, precision, and specificity.     

How China's Political Leadership Elevates Progress

I have been coming to China for more than 30 years. I have traveled all across the country,visiting over 100 cities together with my long-term partner, Adam Zhu, for research and interviews, books and essays, television and documentaries. I have given much thought, over the years, as to what has brought about China's develop-mental miracle. The underlying principles One, a people who work hard to im-prove the lives of their families and the destiny of their country.     

Doing Business the Chinese Way

Nine years ago, the Amsterdam branch of my previous company asked me to come to China and develop the business here. So I got the chance to experience working and living in Beijing.     

变动中的美国律师业:1975至1995年的芝加哥(二)

业务领域的专业化在1975年687个应答的执业律师中，有22．7％的人只在一个领域执业。到了1995年，尽管给应答者出示了一份更长更详细的业务范围清单，675个执业律师中的32．6％指出他们只在一个领域执业。因此，在20年中专业化看起来已经有了实质性的增长。通过对1975年和1995年的研究中使用的领域种类的数目进行控制，我们已经计算出了一个专业化排序索引，使得我们能对这两年中各个领域的专业化程度进行比较。表1列出了27个在两次调查中都有数据的领域，按照它们在1975年中专业化的程度排列。专业化排序索引在0到1之间变动，其中1表示完全…     

Southeast Asia To the Fore

Myanmar seeks to energize ASEAN’s regional networking endeavors Over the course of three days at the World Economic Forum on East Asia, held in Nay Pyi Taw, Myanmar, some 1,000 participants from more than 50 countries debated, among a host of topics, what lies in the future for a robust,     

购并热潮正在袭来

在北京,习惯早起的人都会见到一个熟悉的景象:北京三元食品的汽车和三轮车穿梭在大街小巷中挨家挨户地将牛奶、酸奶酪和其他奶制品送上门。近几年来,三元在北京的市场销售额已经达到1.2亿美元,使这家公司不免萌生向全国发展的念头,但是要做到这一步,首先要扩大自身的生产能力。为此,2000年9月,三元食品出价930万美元收购总部在纽约的卡夫食品北京奶品厂。这次收购将使三元的年产量扩大     

MAGNA CARTA AND THE AMERICAN POLITICAL IMAGINATION: TWO INSTANCES OF HABEAS CORPUS VINDICATED

Magna Carta has long been understood as a source of inspiration for the U.S. Constitution, and especially its enshrinement of the writ of habeas corpus — the right of any prisoner to test his or her detention according to the law. In the “Suspension Clause” of the U.S. Constitution (Article I, Section 8), Congress is granted permission to suspend habeas corpus only “when in cases of Rebellion or Invasion the public Safety may require it.” This article surveys two failed attempts by the U.S. government to suspend the writ of habeas corpus. The first (which was actually the very first such attempt) was in 1807 and followed revelations of the so-called Burr Conspiracy. The second (incidentally the most recent in American history) occurred during the War on Terror and culminated with the Supreme Court’s decision of Boumediene vs Bush in 2008. A close examination of these two historical episodes reveals just how different were the constitutional processes of the early republic and contemporary times. Additionally, comparing the uses of Magna Carta during the two episodes demonstrates marked changes in American political culture. Historical consciousness, vital to early Americans’ understanding of their political system, has shifted to an elite level. Likewise, the protection of fundamental liberties has migrated from the popular branch of government (Congress) to the elite one (the Supreme Court). This article considers the implication of this shift in both constitutional processes and historical consciousness.     

温德教授的珍贵日记

下面几篇译文,译自著名美籍教授罗伯特·温德(Robert Winter)在抗战开始时亲笔写下的日军蹂躏北京清华园的珍贵日记和他发至长沙临时大学的电报。今天,于纪念中国人民抗战57周年际发表,以驳顽梗,省世人。 1937年7月29日,北平沦陷。9月12日,日本宪兵队侵入清华园。10月初,日军开始对清华园野蛮劫掠。北平沦陷前夕,清华大学师生员工开始往南疏散,并组织了北平清华校产保管委员会,负责保管校产。温德教授被留校以外侨身份参加护校,因此得以亲历日军的浩劫,写下了这些珍贵的日记。温德教授笔下,日军侵华的野蛮行径,铁证如山,罪责难逃! 温德教授生于1887年美国印地安纳州。弱冠其时,卒业于美国瓦巴士学院,曾荣获“全美优秀生”的雅誉。翌年得硕士学位。曾留学法国,习法语及文学。后任芝加哥大学法文系教授,其间与就读于该校的闻一多相识。闻一多向他介绍了中国的教育和风情民俗,引起了他莫大的兴趣。1923年,他东来中国,先任教于南京东南大学,讲授英国语言及文学,年余而辍。1925年经闻一多荐举,受聘于清华大学外国文学系,直到1952年院系调整,温德在清华及抗战后在西南联大执教近30年。解放后,经院系调整至北京大学从教。60年沧桑,桃李满天下,他几乎将他的一生都奉献给了中国。1986年12月31日,温德教授刚刚过了     

Greening the Planet Must Not End in Glasgow

Glasgow, the location of COP26, officially known as the 26th Session of the Conference of Parties to the UN Framework Convention on Climate Change, was once a very dirty city.