Search

The influence of SiO2sol-gel coatings on the bending strength of soda lime plate glass samples has been investigated by 3 point bending and double ring bending strength measurements. The samples were prepared by manual glass cutting and were coated with two different types of SiO2coating: A TEOS coating (thickness of about 100 nm) was obtained from sols synthesized by acid catalysis of tetraethoxysilane and a MTKS coating (thickness of about 1 μm) was obtained from a methyl modified nanoparticulate SiO2sol. The coatings were applied by dipping and were densified at 500°C for 1 h. The fracture strength σ0of edge coated plate glass (60×25×3.8 mm), determined by 3 point bending test (according to EN 843-1), was increased after coating with TEOS from σ0=24 MPa to 40 MPa (67% increase). The fracture strength increased to σ0=56 MPa (133% increase) on applying MTKS or a double coating of TEOS followed by MTKS. The evaluation of these measurements using Weibull statistical analysis resulted in mvalues of 4.1 and 4.2 for the TEOS and MTKS coating and 3.5 for double coating (uncoated glasses m=5.7), respectively. These results combined with high resolution secondary electron microscopy investigations led to the conclusion that the strengthening effect of the two different sol-gel systems is due to a partial flaw healing and clamping of the crack sides.

This pilot study utilized a male and a female instructor from a midwestern US university, using a production course and traditional lecture course from each. The instructor was not present during the administration. The study found a correlation between gender of instructor and gender of student in the mass communication courses studied. Although none of the study's hypotheses was supported, significant findings and the high correlation found suggest a relationship between instructors and students of the same gender.

Biochemical studies and experiments with cells have shown that trialkyllead (R3Pb+), a degradation product of tetraalkyllead (R4Pb) antiknock agents, is highly cytotoxic. Trialkyllead may occur in rain and fog in concentrations much higher than those reported so far. From these data it has been proposed that trialkyllead may represent one of the factors responsible for the present forest decline. This article reviews the chemistry of trialkylead, its molecular interactions, its toxic effects on cells and on plant cells in particular, and its occurrence in the environment. Evidence for and against the involvement of trialkyllead in forest decline will be discussed.

Mit einer vereinfachten Methodik der röntgenhistoradiographischen Trockengewichtsbestimmung ohne Referenzsystem wurden vergleichende Untersuchungen mit dem Bakerschen Interferenzmikroskop an Zellausstrichen von Bullenspermien und -thymuslymphocyten, Froscherythrocyten und Plattenepithelien der menschlichen Mundschleimhaut durchgeführt. Die gewonnenen Ergebnisse stimmen gut überein. Die Abweichungen betragen etwa 10%. Sie geben einen Einblick in die Fehlerbreite beider Methoden und bestätigen insbesondere die Genauigkeit der von uns angewandten quantitativen röntgenhistoradiographi schen Methodik.

For the prognosis and long-term stability of an implant, for example a hip- or knee-implant, the anchorage to the bone is of critical importance. Normally for this anchorage bone cement is used, which achieves sufficient retention to spongious bone structure. If there is the need for osteosynthesis of midfacial fractures for surgical therapy, in some situations it would be clinically preferable to fix the reconstruction plates without the usual system using screws. This is the aim of the new adhesive fixing technology which is presented in this article. The structure of bone in midface, however, is cortical and such a smooth surface will allow only insufficient retention forces between bone and bone cement. In order to obtain a good adhesion at cortical bone nevertheless, we have to apply a bone bonding agent similar to techniques used in dentistry, which are based on dentin bonding agents, because there are different wetting properties of the hydrophilic bone and the hydrophobic bone cement monomers.Determination of achievable bond strength was done in a tension test ex vivo. Reconstruction plates were fixed with bone cement at bovine bone conditioned with a bone bonding agent developed for this field of application. With bond strengths up to 6 MPa it is assumed that an adhesive fixation of reconstruction plates at cortical bone structure is possible using the developed amphiphilic bone bonding agent.

Introduction:Acute myocardial infarction (MI) is one of the most time-sensitive diagnoses made in the emergency department (ED). Troponin (TNI) measurement is an invaluable tool; however, its utility depends on the clinical context and is highest where there is a strong pre-test probability. Studies show that most TNI elevations are due to non-cardiovascular causes; however, elevated TNI has been associated with increased morbidity and mortality, often prompting additional investigations. The aim of our study was to compare 1-year cardiac outcomes of patients who presented to the ED with non-cardiac complaints and elevated TNI who had further cardiac testing versus those who did not. Methods:We conducted a retrospective chart review of patients ≥18 seen in the ED for non-cardiac complaints with a high TNI from January-June 2016. Patients were stratified into two groups: 1) those who received diagnostic testing for ischemia and/or a cardiac consultation and 2) those without cardiac consultation or testing. Data was also collected on major adverse cardiac events within 1-year of ED presentation. Chi-squared analysis assessed the difference in proportions of outcomes between groups. We present our preliminary data. Results:In total, 1500 patients met inclusion criteria and 861 have been analyzed thus far. Of these 861, 209 went on to have either diagnostic testing for ischemia and/or a cardiology consult while 652 had no further investigations. There was no statistically significant difference in the proportion of patients who developed unstable angina (p = 0.9824), ST-elevation myocardial infarction (STEMI) (p = 0.9956), non-STEMI (p = 0.9008), stroke/TIA (p = 0.9657), revascularization (p = 0.8873), cardiac hospitalization (p = 0.9446) or died (p = 0.8972), within 1-year of their ED presentation. Conclusion:In patients with isolated elevated TNI and non-cardiac complaints, preliminary data showed no difference in mortality or cardiac event rates between those who had further testing/consultations and those who did not. TNI ordering could be cautiously limited to only presenting complaints/preliminary diagnoses likely to have cardiac etiology or sequelae or those in whom further testing would impact management/outcomes. Quality of care may be improved by reducing length of stay in the ED and potential risks of unnecessary tests. Future studies include determining cost implications and classifying what level of TNI elevation in non-ACS patients may predict a future cardiac outcome.