Streptokinase-induced activation of the kallikrein-kinin system and of the contact phase in patients with acute myocardial infarction

Thrombolytic therapy in acute myocardial infarction (AMI) is hampered by a considerable reocclusion rate. Thrombin activity is enhanced, and contact-system activation via plasminemia might be possible. Prospectively we examined the contact phase and the kallikrein-kinin system and additional molecular markers of hemostasis and fibrinolysis in AMI. In 22 patients with AMI, blood sampling was performed at admission and < or =10 days afterward. Eleven patients received 1.5 Mio U streptokinase (group A) and were compared with 11 AMI patients without thrombolytic therapy (group B). All patients had systemic heparinization (5,000 IU bolus, i.v.; 1,000 IU/h, i.v.). In group A (vs. group B), the kallikrein-factor XII system was significantly activated (3 h after start of therapy): kallikrein activity 140 +/- 41 (vs. 43 +/- 8) U/L (p < 0.05); kallikrein inhibition 87 +/- 9 (vs. 113 +/- 7%; p < 0.05), and factor XII 70 +/- 14 (vs. 94 +/- 6%). C1 inhibitor and factor XII inhibition were decreased. High-molecular-weight kininogen consumption indicating bradykinin generation was enhanced (p < 0.01). In group A, thrombin activity (TAT) was increased, and a hypercoagulative state with increased fibrin degradation products (d-dimer) was found. Plasmin activation in group A was reflected by decreased plasminogen and antiplasmin levels (p < 0.01). The findings indicate that streptokinase induces activation of the contact phase-kinin system in vivo associated with a consecutive increase of thrombin and bradykinin generation. Activation of this pathway might substantially contribute to reocclusion after initially successful thrombolytic therapy and to hypotensive reactions observed after streptokinase.     

Cold cracking behaviour of two medium-strength steels StE 355 containing 0.10 and 0.13 % C

Three dimensional instrumented restraint cracking (IRC) tests on steel StE 355. Welding of double-V-joints with basic electrodes in dry or moistured state. Critical heat input for prevention of delayed cracking. Correlation with hardness values in the coarse grained HAZ. Comparison of IRC nominal fracture stresses with literature results of implant tests.     

Effect of weld metal composition and welding conditions on δ-ferrite and CVN toughness of austenitic-ferritic weld metal

In the present investigation, the effect of base plate and filler wire composition as well as of welding conditions on δ-ferrite contents and toughness of austenitic-ferritic stainless steel weld metal has been established. According to previous work, the δ-ferrite contents are not only depending on chemical composition but also on cooling conditions of the weld metal. The application of δ-γ-CCT diagrams is recommended. Increasing δ-ferrite contents lower the CVN toughness of the weld metal, which should be taken into consideration before recommending filler materials and welding conditions.     

Entwicklung und Aussagen eines instrumentierten Einspann-Schweißversuchs

Bedeutung des schweißbedingten zeitlichen Verlaufs der Reaktionskräfte in allen drei Richtungen für die Schweißeignung von Stählen. Entwicklung und Aussagemöglichkeiten des instrumentierten Einspannschweißversuchs. Erste Ergebnisse zum Einfluß der Schweißzeit und Blechdicke auf Reaktionskräfte und plastische Formänderungen von Heftschweißverbindungen des Werkstoffs St 37-1.     

Micro-machining processes for microsystem technology

By means of experiments it could determined that micro-machining processes as grinding, drilling and milling are a good addition to the established production technologies in micro technology. To machine hard and brittle materials grinding with diamond tools is well suitable, but the kinematics of the grinding process, as well as the process strategy has a significant influence on the machined surface quality and the chipping of the edges. The study of micro-machining processes showed, that micro cutting processes are not just a miniaturisation of the conventional cutting technology. The reduced tool stiffness of micro drills caused by the changes of geometry requires an adjustment of the complete drilling processes. Sharp cutting edges are an essential requirement for the fabrication of very small structures. So, using single edged micro milling cutters made of diamond significant smaller structures could be made compared to using conventional milling cutters made of tungsten carbide. Furthermore, acoustic emission sensors proved to be suitable for detecting the tool position after a change of the tool with a high accuracy.     

The Ketosynthase Domain Controls Chain Length in Mushroom Oligocyclic Polyketide Synthases

The nonreducing iterative type I polyketide synthases (NR-PKSs) CoPKS1 and CoPKS4 of the webcap mushroom Cortinarius odorifer share 88 % identical amino acids. CoPKS1 almost exclusively produces a tricyclic octaketide product, atrochrysone carboxylic acid, whereas CoPKS4 shows simultaneous hepta- and octaketide synthase activity and also produces the bicyclic heptaketide 6-hydroxymusizin. To identify the region(s) controlling chain length, four chimeric enzyme variants were constructed and assayed for activity in Aspergillus niger as heterologous expression platform. We provide evidence that the β-ketoacyl synthase (KS) domain determines chain length in these mushroom NR-PKSs, even though their KS domains differ in only ten amino acids. A unique proline-rich linker connecting the acyl carrier protein with the thioesterase domain varies most between these two enzymes but is not involved in chain length control.     

汉语连续语音识别之音素声学模型的改进

研究基于主元音音素基元的声学模型的改进。由于汉语语音特点,主元音模型得到了广泛的应用。通过分析主元音音素模型,发现该模型存在词组音节序列字界线有歧义,从而提出主元音的改进方法以明确音节序列中字的分界,减小基元规模,提高语音系统识别率。为了描述连续语意中的协同发音现象,还针对改进后的主元音基元,设计了相应的有调问题集,利用决策树的参数共享策略建立了上下文相关的音素模型。实验结果表明,改进后的有调音素集合在削减了原有基元个数的基础上,字误识率(CER)有0.4%-0.6%的明显改善。     

Zur sicheren Anwendung feuerverzinkter Stahlträger

Reliable application of hot dip zinc coated steel beams. Hot dip zinc coated steel beams as used e.g. for parking houses may be susceptible to cracking, with cracks along the beam axis starting from welds of partial end plate connections, in some cases also cracks at the bottom flange transverse to the beam axis occurred which propagated from local plastic deformations e.g. from cold forming for pre‐cambering the beams. The report describes the various causes interacting in the formation of the cracks according to the present state of knowledge and also gives tentative recommendations for the choice of material, structural detailing, fabrication and the hot dip coating process to avoid cracks in the future.