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Our study investigated the effects of moderate doses of fentanyl and sufentanil versus high-dose sufentanil on cerebral hemodynamics by using transcranial Doppler ultrasonography (TCD). Thirty American Society of Anesthesiologists (ASA) II and III patients scheduled for elective coronary artery bypass graft (CABG) were studied after Institutional Review Board (IRB) approval and informed consent. The evening before surgery, all patients received oral flurazepam (1 mg/kg), Atropine (0.4 mg/70 kg s.c.) and a combination of droperidol (70 micrograms/kg s.c.) plus fentanyl (1.5 micrograms/kg s.c.) were given as preanesthetic medication 1 h before induction of anesthesia. Anesthesia was induced with either 25 micrograms/kg fentanyl i.v. (group 1, n = 10), 3 micrograms/kg sufentanil i.v. (group 2, n = 10) or 6 micrograms/kg sufentanil i.v. (group 3, n = 10). All patients received 100 micrograms/kg pancuronium i.v. With the induction of respiratory depression, assisted ventilation was performed followed by controlled ventilation to maintain normoxia and normocapnia (FiO2, 1.0). Cerebral blood flow velocity (CBFV, cm/s) was measured continuously in the middle cerebral artery by using a bidirectional 2-MHz TCD system. Monitoring included heart rate (HR, beats/min), direct mean arterial blood pressure (MAP, mm Hg), and PaCO2. Physiologic variables including arterial blood gases were measured at baseline, 5 min, and 10 min after infusion of fentanyl or sufentanil. In all patients, HR, MAP, end-tidal carbon dioxide tension (PetCO2), and PaCO2 were constant over time and did not differ between groups. CBFV did not change with moderate doses of fentanyl (group 1) or sufentanil (group 2). In contrast, infusion of high-dose sufentanil (group 3) was associated with 27 to 30% decreases in CBFV (p < 0.05). Our results suggest that sufentanil decreases CBFV in a dose-related fashion with a threshold effect. Increases in CBFV and CBF seen in previous studies may be related to an increasing PaCO2 when maintenance of normocarbia is based on only real-time capnography with a constant PetCo2 rather than additional arterial blood gas monitoring.

Open-celled metallic foams with their specific structural properties are attractive candidates for a wide range of applications in the field of catalyst supports, process, and energy technologies. However, the material is so far not introduced as an engineering material and needs to be characterized for the respective applications. The metallic foams, especially in combination with cover plates, have a high potential for applications as light weight and functional materials. In this article, an industrial manufacturing process is described, which allows to produce a wide range of different qualities of foam with a variety of tailored alloys and pore sizes. The foam material can be stacked and co-sintered with top layers to high-strength sandwich structures. The mechanical properties evaluated in shear and compression tests are promising for couple of aircraft applications.

The Myc protein activates transcription as part of a complex with its partner protein, Max. Myc-transformed cells are also characterised by the loss of expression of a number of genes and this repressive effect of Myc on gene expression may not be mediated by the Myc/Max complex. We recently isolated by two-hybrid cloning a novel zinc-finger protein that associates with the carboxy-terminus of Myc. We have termed this protein Miz-1 (Myc-interacting zinc finger protein). Some of the properties of Miz-1 suggest that it may be involved in gene repression by Myc in vivo.