波罗的海西南Achterwasser泻湖富黄铁矿沉积物中痕量元素成岩作用

本文研究了黄铁矿形成背景下波罗的海无潮的Oder河口中一个浅泻湖Achterwasser缺氧沉积物中痕量元素（V、Cr、Co、Cu、Zn、As、Cd、Ba、U）的早期成岩作用。溶解的主要氧化还原参数呈现出一个双层分布：具有临时性信号偶尔被再悬浮的浮泥层（FM）和之下已永久建立成岩序列的沉积物。强烈的微生物呼吸作用导致了FM最上部数毫米中氧气的迅速耗尽。FM中Mn、Fe和硫酸盐还原带互相重叠。永久缺氧沉积物部分出现低硫酸盐条件下河口沉积物的典型特征。黄铁矿化度（DOP）范围从FM中的50％30到50cm深度处〉90％的极高值。沉积物表层处的黄铁矿由硫化亚铁与中间态硫通过多硫途径形成。相比之下，之下的永久缺氧沉积物中强烈的黄铁矿化则是通过水相的铁硫配合物吸附到原已在表层形成的黄铁矿晶体上的矿物生长完成的。被研究的痕量元素呈现出上述成岩过程紧密耦合但有差异行为模式：（i）Zn、Cu和Cd从沉积物的薄有氧层中的有机质被释放并向上扩散穿过沉积物／水界面以及向下扩散以单硫化物的形式被捕获；（ii）V、Cr、Co和As在氢氧化铁和氢氧化锰的还原性溶解过程中被释放；（iii）U从孔隙水中的移除是由于U（VI）到U（IV）的还原，它与FM中的Fe还原同时发生；（iv）Ba的分布受硫酸盐还原带中自生重晶石的还原性溶解伴随的向上扩散和再沉积控制。痕量元素Co、Mn和As被黄铁矿的纳入最强烈，Cu和Cr中等，而U、Zn、Cd、V和Ba很少至可忽略。本研究观察到的趋势在很大程度上与前人的研究一致并可通过配位体交换的不同速率加以解释。配位体交换和由此导致沉积动力学的慢和快也被沿岩心向下（Mn、Cr、Co和As）增加或持续低（Zn、Cu、Cd）的孔隙水浓度所呈现。Co、Cu、Zn和As沿岩心向下增加的痕量元素黄铁矿化度（DTMP）与黄铁矿生长类似，都是由于已存在的黄铁矿物对硫化配位体或砷含氧阴离子的吸附。

Pathologic Q Waves and Prolonged QTc Time in Preoperative ECG Are Predictive for Perioperative Cardiovascular Events

Aims: The value of ECG in the perioperative risk stratification under modern treatment options is uncertain. The main objective of the present analysis was to determine the usefulness of a pre-operative ECG derivation for evaluating the risk of perioperative morbidity and mortality. Methods: We performed a secondary analysis of the prospective, international, multicenter, observational “No-Risk” Study (N-terminal B-type natriuretic peptide [NT-proBNP] for the assessment of the perioperative cardiac risk after major noncardiac surgery) to determine the prognostic value of 12-lead ECG. Inclusion criteria were age >55 years and at least one of the following cardiovascular risk factors: arterial hypertension, diabetes mellitus, dyslipidemia, active smoking, and family history positive for coronary heart disease. The combined primary endpoint included total mortality, acute myocardial infarction (NSTEMI and STEMI), cardiopulmonary resuscitation, heart failure, and asystole or ventricular fibrillation during hospitalization. ECGs from 616 patients enrolled from 2006 to 2009 prior to noncardiac surgery in the No-Risk Study were analyzed. Results: The mean age was 67.6 (±8.1) years;300 (48.7%) patients were male. Fourteen (2.3%) patients suffered from the combined primary endpoint while in the hospital. In Kaplan-Meier analyses, a pathologic Q wave and QTc > 500 ms were significantly related to the incidence of the primary endpoint (p p = 0.042, respectively), whereas other ECG parameters such as LBBB, RBBB, PQ interval, QRS interval, and others were not related to worse in-hospital outcome. Conclusion: The 12-lead ECG is still an important diagnostic tool for perioperative risk assessment of cardiovascular events in noncardiac surgery in patients at risk.

生物学模型与海洋学模型的耦合

海洋生态系统的动力问题,如可观测的化学—生物量的时空变化是由于生物和物理过程决定的。预报海洋系统的未来发展需要有一个理论框架,如模型,而这个模型是根据对相关的各个不同过程的研究和了解而发展的。从理论上描述海洋系统的自然方法似乎是把化学生物模型与环境模型结合在一起。但是,环境模型相对比较先进,而化学—生物过程的定量理论描述比较落后。本文讨论了一些关于发展相容理论的方法和问题,指出了海洋生物学模型和海洋学模型耦合的潜在益处。