Surface pre-treatment and its influence on electric functionality and the formability of screen printed steel sheet

Industrial development focuses on multifunctional components due to rising requirements regarding e.g. light weight and security. A beneficial possibility to extend the functionality of structural components produced by metal forming is the usage of screen printed metal blanks. During the printing process insulating and electric inks are applied. The examined printed layer structure consists of three insulating full area layers and one conductive layer in the form of strain gauges. The two applied inks are solvent-based and printed with a half-automatic machine. To improve the adhesion and electric functionality, the impact of different mechanical and physical surface pre-treatments on the electrical characteristics is investigated in tensile tests. In particular, abrasive peening, ball peening, grinding and polishing (mechanical) and in addition plasma and corona technology (physical) were utilised. Contrary to expectations, the surface pre-treatment does not affect the adhesion to the steel sheet. The cracking of the printed strain gauges takes place prior to the delamination of the coating. Explanatory models are elaborated. They are based on the measurements of roughness, surface energy, edge sharpness and the electrical resistance of printed conductive structures before, during and after forming.     

A computer model of intracranial dynamics integrated to a full-scale patient simulator

The ability to visualize intracranial dynamics during simulated clinical scenarios is a valuable tool for teaching brain physiology and the consequences of different medical interventions on the brain. Studies have isolated physiologic variables and shown their effects on brain dynamics. However, no studies have shown the combined effects of these variables on intracranial dynamics. This brain model offers one approach that brings all these relationships together and shows how they affect the dynamics of the brain. The brain model obtains its physiologic inputs from a full-scale patient simulator which responds to clinical interventions. This integration allows individuals working on the patient simulator to see the effects of their actions on brain dynamics. The brain model gives a real-time display of intracranial events (cerebral metabolic rate, cerebral blood flow, cerebral blood volume, cerebral perfusion pressure, and intracranial pressure) and responds to changes in the pulmonary and cardiovascular condition of the patient simulator.     

Five days of oral topotecan (Hycamtin), a phase I and pharmacological study in adult patients with solid tumours

Topotecan is a specific inhibitor to topoisomerase I. An oral formulation of topotecan is available with a bioavailability of 32-44% in humans. A phase I and pharmacological study of the oral formulation of topotecan administered daily for 5 days every 21 days was performed in adult patients with solid tumours to determine the maximum tolerated dose (MTD). Adult patients with a WHO performance status < or = 2 adequate haematological, hepatic and renal functions, with malignant solid tumours refractory to standard forms were entered into the study. Pharmacokinetics were performed on days 1 and 4 of the first course using a validated high performance liquid chromatographic assay. 29 patients entered the study, all patients were evaluable for toxicity and response. The doses studied in the 29 patients were 1.2, 1.8, 2.3, 2.7 mg/m2/day and a fixed dose of 4 mg/day without surface area adjustment. A total of 109 courses were given. Dose limiting toxicity (DLT) was reached at a dose of 2.7 mg/m2/day and consisted of CTC (NCI-Common Toxicity Criteria) grade IV granulocytopenia. The regimen was well tolerated. Non-haematological toxicities were mild, including fatigue, anorexia, nausea, vomiting and diarrhoea. A significant correlation was observed between the percentage decrease in white blood cells versus the area under the curve (AUC(t)) of topotecan lactone (R = 0.76 P < 0.01) which was modelled by a sigmoidal Emax function. The correlation coefficient between the absolute topotecan dose administered and the AUC(t) was R = 0.52 (P = 0.04). Pharmacokinetics of the fixed dose of 4 mg/day were comparable to the 2.3 mg/m2/day dose. DLT in this phase I study of five daily doses of oral topotecan every 21 days was granulocytopenia. The recommended dose for phase II studies is 2.3 mg/m2/day or alternatively, a fixed dose of 4 mg/day.     

The orphan granzymes of humans and mice

The granzyme/perforin pathway is a central pathway for lymphocyte-mediated killing in both the innate and adaptive immune systems. This pathway is important in a variety of host defenses, including viral clearance and tumor cell killing, and its dysregulation results in several human and rodent diseases. To date, the majority of reports in this field have concentrated on the functions of granzymes A and B. Recent reports, however, suggest that the non-A/non-B 'orphan' granzymes found in both humans and mice are potentially significant. Although the functions of these orphan granzymes have yet to be fully established, initial data suggests their importance in both immune and nonimmune cells.     

Rupture recurrence after surgical repair of postinfarction ventricular septal rupture. Influence of early thrombolysis

OBJECTIVES: The aim of this study was to identify factors causing rupture recurrence after surgical repair of postinfarction ventricular septal rupture and to evaluate the indication for reoperation. PATIENTS: Recurrence of rupture was analysed in 25 out of a series of 109 patients who underwent surgical repair for postinfarction ventricular septal rupture between 1980 and 1992 in our institution. RESULTS: The mean interval between initial operation and recurrence was 3.6 days with a median of 2 days. Multivariate logistic regression analysis identified early thrombolysis after infarction (P = 0.0085) as a risk factor for recurrence of the rupture. Rupture recurrence occurred more in the anterior then in the posterior infarction site, although non-significant. Reoperation was indicated in 15 patients, in 13 for postrecurrent cardiac failure. The main determinant of cardiac failure was a large postrecurrent shunt (P = 0.05). The mean interval between initial operation and reoperation was 136 days with a median of 101 days. In 6 patients a combined apical ventricular septal rupture recurrence and anterior ventricular aneurysm was found, in 9 patients the recurrent rupture was proximally located, without concomitant aneurysm formation. Of 15 patients who were reoperated, one died in hospital and three after the in-hospital period. Of 10 patients treated conservatively, one died in hospital and two after the in-hospital period. One residual ventricular septal rupture closed spontaneously. CONCLUSIONS: Rupture recurrence is mainly determined by early thrombolysis. Postrecurrent cardiac failure, as the main indication for reoperation, is dependent on postrecurrent shunt size.     

Dissection of the carotid artery and vertebral artery--diagnosis and therapy

Carotid and vertebral artery dissections typically occur in young adults after major trauma, although they can arise spontaneously or after trivial injury. Many patients with carotid dissections have minor symptoms such as a subject bruit or Horner's syndrome. Cephalic pain is also frequent and often inaugural in carotid dissection. However, extracranial dissection is a well recognised cause of ischaemic stroke. The diagnosis of dissection was based on angiographic findings. Noninvasive imaging also allows prompt and reliable diagnosis. Our goal was to demonstrate the spectrum of neuroradiologic (CT, MR and angiographic) findings in craniocervical arterial dissection and compare the diagnostic utility of CT, MR, MR angiography. Clinical data imaging studies, and outcome were reviewed and compared with the results in four patients with carotid artery dissection.     

Developmental and behavioral effects of prenatal primidone exposure in the rat

Pregnant Sprague-Dawley rats were administered primidone (PRM) by oral gavage on gestation days 8-17 in doses of 0.40, and 80 mg/kg. Although these doses of PRM did not produce significant differences in litter size, birth weight, mortality, date of attainment of developmental landmarks or measures of preweaning reflex and motor development, there were a number of significant differences that developed as the animals approached and entered adulthood. When tested as adults, the 80 mg/kg male rats showed a deficit in the performance of an eight-arm radial maze task. These same animals showed a significant reduction in open field activity when tested as adults. In addition, both male and female PRM-treated animals showed reduced body weights at different periods corresponding to onset of sexual maturation during development. These findings are consistent with the larger body of literature reporting on the neurobehavioral teratology of phenobarbital, including its ability to produce lesions in the hippocampus and endocrine dysfunction resulting in reproductive deficits. These results suggest that PRM produces its adverse effects as a result of its metabolism to phenobarbital, which in turn affects the limbic system.