HPLC-MS/MS法测定人体血浆中丙泊酚的浓度及其药动学研究(英文)

目的:采用HPLC-MS/MS法检测人体血浆中丙泊酚的浓度,并将该方法用于临床药动学研究。方法:采用Zorb-ax Eclipse XDB-C18(50 mm×4.6 mm,5μm)色谱柱分离;流动相为甲醇和0.1%氨水二元梯度洗脱系统;流速为0.3 mL.min-1;通过电喷雾离子化电离源(ESI),采用负离子检测。结果:线性范围为0.010～12μg.mL-1,相关系数≥0.99,定量下限为0.010μg.mL-1。日内及日间精密度不高于15%,准确度的相对误差(RE)在-2.0%～5.0%。药代动力学符合三室模型,清除率为0.029 L.min-1.kg-1,中央室分布容积为0.60 L.kg-1,血药浓度消除半衰期t1/2α为0.84 min,t1/2β为6.7 min,t1/2γ为128.7 min。结论:该方法高效、灵敏,特异性强,准确度、精密度好,适用于丙泊酚药物动力学研究。     

Morphology,Microstructure, and Mechanical Properties of S32101 Duplex Stainless-Steel Joints in K-TIG Welding

In this paper, the {"type":"entrez-protein","attrs":{"text":"S32101","term_id":"422005","term_text":"pir||S32101"}}S32101 duplex stainless steel welded joints were produced by a K-TIG welding system. The weld geometry parameters under different welding speeds were analyzed by combining the morphological characteristics of the keyhole. The microstructure and impact toughness of the base metal and weld metal zone under different welding speeds were studied. The experiment results show that the welding speed has quite an effect on the geometry profile of the weld. In addition, the characteristic parameters of the keyhole can effectively predict the geometry profile of the weld. The test results prove that the microstructure, Σ3 coincidence site lattice grain boundary, and phase boundary of ferrite and austenite have an effect on the impact property of the weld metal zone. When the proportion of the austenite, Σ3 coincidence site lattice grain boundary and random phase boundary increased, the impact property of the weld metal zone also increased.     

Antepartum testing in patients with hypertensive disorders in pregnancy

Antepartum fetal testing in pregnant patients with hypertensive disorders may be beneficial in preventing stillbirth and hypoxic sequelae in the fetus. The highest risk patients in this category are those with intrauterine growth restriction, superimposed preeclampsia, associated medical complications such as diabetes, systemic lupus erythematosis, chronic renal disease, or history of a prior stillbirth. The current recommended method of primary testing is a twice weekly modified biophysical profile with either a full BPP or a contraction stress test for backup evaluation of those patients with lack of reactivity or decreased amniotic fluid volume on a modified biophysical profile. Even uncomplicated patients with chronic hypertension or pregnancy-induced hypertension carry an increased risk of perinatal mortality and for these patients testing should begin at 33 to 34 weeks gestation. Patients with complications of intrauterine growth restriction, preeclampsia, diabetes, systemic lupus erythematosis, or chronic renal disease should have antepartum testing begin when intervention for fetal indications is judged to be appropriate, usually beginning at about 26 weeks gestation. Doppler velocimetry may be helpful in further evaluation of those patients in the early third trimester with abnormal primary testing.     

Integrated testing and management in fetal growth restriction

Growth-restricted fetuses are at higher risk for poor perinatal and long-term outcome than those who are appropriately grown. Multiple antenatal testing modalities can help document the sequence of fetal deterioration. The full extent of this compromise is best identified by a combination of fetal biometry, biophysical profile scoring, and arterial and venous Doppler. In the preterm growth-restricted fetus, timing of delivery is critically determined by the balance of fetal versus neonatal risks. In the near-term fetus, accurate diagnosis continues to be a challenge as unrecognized growth restriction contributes to a significant proportion of unexplained stillbirths. In this review, we present an integrated diagnostic and surveillance approach that accounts for these factors.     

Fetal growth restriction

Normal fetal growth is determined by the genetically predetermined growth potential and further modulated by maternal, fetal, placental, and external factors. Fetal growth restriction (FGR) is a failure to reach this potential and is clinically suspected if sonographic estimates of fetal weight, size, or symmetry are abnormal. Integration of fetal anatomy assessment, amniotic fluid dynamics, uterine, umbilical, and fetal middle cerebral artery Doppler is the most effective approach to differentiate potentially manageable placenta-based FGR from aneuploidy, nonaneuploid syndromes, and viral infection. Although placental dysfunction results in a multisystem fetal syndrome with impacts on short- and long-term outcome, only cardiovascular and behavioral responses are helpful to guide surveillance and intervention. Early-onset FGR before 34 weeks gestation is readily recognized but challenging to manage as questions about optimal delivery timing remain unanswered. In contrast, near-term FGR provides less of a management challenge but is often missed as clinical findings are more subtle. Once placenta-based FGR is diagnosed, integrating multivessel Doppler and biophysical profile score provides information on longitudinal progression of placental dysfunction and degree of fetal acidemia, respectively. Choosing appropriate monitoring intervals based on anticipated disease acceleration and intervention when fetal risks exceed neonatal risks are the prevailing current management approaches.     

智能代理在网络课程监控中的应用模式研究

网络课程作为终身教育学习资源的一种,越来越受到人们的重视.在网络课程中,是否具备良好的监控能力,是影响学习者学习效果的关键因素.而目前的网络监控普遍存在智能程度不高问题,无法满足网络监控的需要.该文将智能代理技术与电子学档结合起来对网络课程进行监控,以期对今后网络课程监控方面的研究提供一些帮助.