Highly efficient separation of actinides from lanthanides by a phenanthroline-derived bis-triazine ligand

The synthesis, lanthanide complexation, and solvent ex- traction of actinide(III) and lanthanide(III) radiotracers from nitric acid solutions by a phenanthroline-derived quadridentate bis-triazine ligand are described. The ligand separates Am(III) and Cm(III) from the lanthanides with remarkably high efficiency, high selectivity, and fast extraction kinetics compared to its 2,2'-bipyridine counterpart. Structures of the 1:2 bis-complexes of the ligand with Eu(III) and Yb(III) were elucidated by X-ray crystallography and force field calculations, respec-tively. The Eu(III) bis-complex is the first 1:2 bis-complex of a quadridentate bis-triazine ligand to be characterized by crystallography. The faster rates of extraction were verified by kinetics measurements using the rotating membrane cell technique in several diluents. The improved kinetics of metal ion extraction are related to the higher surface activity of the ligand at the phase interface. The improvement in the ligand's properties on replacing the bipyridine unit with a phenanthroline unit far exceeds what was anticipated based on ligand design alone

Elevated expression of polymorphonuclear leukocyte elastase in breast cancer tissue is associated with tamoxifen failure in patients with advanced disease

Besides a variety of other proteases, polymorphonuclear leukocyte elastase (PMN-E) is also suggested to play a role in the processes of tumour cell invasion and metastasis. Yet, there is only limited data available on the relation between the tumour level of PMN-E and prognosis in patients with primary breast cancer, and no published information exists on its relation with the efficacy of response to systemic therapy in patients with advanced breast cancer. In the present study, we have measured with enzyme-linked immunosorbent assay the levels of total PMN-E in cytosolic extracts of 463 primary breast tumours, and have correlated their levels with the rate and duration of response on first-line tamoxifen therapy (387 patients) or chemotherapy (76 patients) in patients with locally advanced and/or distant metastatic breast cancer. Furthermore, the probabilities of progression-free survival and postrelapse survival were studied in relation to the tumour levels of PMN-E. Our results show that in logistic regression analysis for response to tamoxifen treatment in patients with advanced disease, high PMN-E tumour levels were associated with a poor rate of response compared with those with low PMN-E levels (odds ratio: OR, 0.40; 95% CI, 0.22-0.73; P = 0.003). After correction for the contribution of the traditional predictive factors in multivariate analysis, the tumour PMN-E status was an independent predictor of response (P = 0.01). Furthermore, a high tumour PMN-E level was related with a poor progression-free survival (P<0.001) and postrelapse survival (P = 0.002) in a time-dependent analysis. In contrast, the tumour level of PMN-E was not significantly related with the efficacy of response to first-line chemotherapy in patients with advanced breast cancer. Our present results suggest that PMN-E is an independent predictive marker for the efficacy of tamoxifen treatment in patients with advanced breast cancer

Trennwände als wirksamer Schutz vor Bioaerosolen in Klassenzimmern - eine experimentelle Untersuchung

Introduction: During a pandemic, protective measures to prevent bio-aerosol based infections, such as Corona Virus Infection Disease 19 (COVID 19), are very important. Everyday face masks can only partially block aerosols, and their effectiveness also depend on how well the person is wearing it. They are recommended for classroom situations during high pandemic activity. However, 'unprotected' communication with and among children is fundamental from the pedagogical and psychological point of view for normal psychosocial development and teaching. Partition walls around the persons can theoretically provide substantial standardized mechanical protection against the spread of droplets and aerosols, either as additional protection to face masks or as an alternative. Methods: In the present research, the protection effectiveness of partition walls was investigated. With mannequin heads, fog generators, line lasers and a classroom-like setup with protective walls, flow visualization and aerosol concentration measurements were performed. Additionally, an active fan-suction system was tested to remove the channelled aerosols on top of the partition walls before they reach other persons in the room.Results: It was found that partition walls protect neighbours from bio-aerosol contact regardless of whether they wear masks or not. The combination with standardized room ventilation enforces this effect. Moreover, the experiments performed here clearly showed that partition walls may protect neighbours from bio-aerosols better than suboptimally fitting everyday face masks only.Conclusion: Partition walls are the most effective protection against infectious bio-aerosols in classroom settings and should be combined with standardized ventilation as the preferred method for classrooms during the current COVID 19 pandemic.Einführung: Während Pandemien, wie der aktuellen "Corona Virus Infection Disease 19 (COVID 19)" Pandemie, ist es wichtig, geeignete Schutzmaßnahmen zu etablieren, die eine durch Bioaerosole verursachte Infektion verhindern können. Alltags-Mund-Nasenmasken sind generell für das Tragen in Unterrichtsräumen während einer Pandemie empfohlen. Dennoch können sie die Ausbreitung von Aerosolen nur teilweise verhindern. Ihre Wirksamkeit hängt sehr davon ab, wie korrekt sie getragen werden. Unter pädagogischen und entwicklungspsychologischen Aspekten ist es fundamental wichtig, dass die Kommunikation zwischen Lehrer und Schüler ungehindert unter Einbeziehung der gesamten Mimik des Gesichts stattfinden kann. Trennwände zwischen den im Raum befindlichen Personen könnten theoretisch einen optimalen Schutz vor Tröpfchen und Aerosolen sicherstellen und entweder als Alternative oder Ergänzung zum Mund-Nasen-Schutz angewandt werden.Methode: In der vorliegenden Studie wurde die Effektivität von Trennwänden zum Schutz vor Bioaerosolen untersucht. Mit sogenannten Figurenköpfen, einem Nebelgenerator, einem Linienlaser und einer Sitzanordnung entsprechend einem simulierten Unterrichtsraum wurde mit einerseits Strömungssichtbarmachung und andererseits mit Konzentrationsmessungen der Partikelgrößen die Aerosolausbreitung im Raum untersucht. Mit einer aktiven Absauglüftungsanlage wurde zusätzlich untersucht, wie sich die Aerosole aus dem Unterrichtsraum entfernen lassen, bevor sie in Kontakt mit anderen Personen kommen.Resultate: Die Ergebnisse dieser Untersuchung zeigen, dass Trennwände den direkten Nachbar vor Bioaerosol Kontakt schützen, unabhängig ob Mund-Nasenmasken getragen werden. Die Kombination mit einem Absauglüftungssystem verstärkt diesen positiven Effekt. Zusätzlich zeigen die Messungen, dass Trennwände den direkten Nachbar besser schützen als Alltags-Mund-Nasenmasken.Schlussfolgerung: Trennwände sind die effektivste Schutzmaßnahme gegen infektiöse Bioaerosole in Unterrichtsräumen. In Kombination mit einem Absauglüftungssystem sollten sie als die bevorzugte Schutzmaßnahme während der aktuellen COVID 19 Pandemie angewandt werden

On how the generation of lift can be explained in a closed form based on the fundamental conservation equations

The generation of lift is a fundamental problem in aerodynamics and in general in fluid mechanics. The explanations on how lift is generated are often very incomplete or even not correct. Perhaps the most popular explanation of lift is the one with the Bernoulli equation and with the longer path over an airfoil as compared to the path below the airfoil, assuming the flow arrives at the same time at the trailing edge on both paths. This is an intuitive assumption, but no equation is derived from this assumption. In some explanations the Bernoulli equation is also complemented with Newton´s laws of motion. In other explanations Newton´s law is said to be the only explanation. Other explanations mention the Venturi suction effect to explain the generation of lift. In books of aerodynamics and on the homepage of well-known research institutes the explanations are, although better and partially correct, still very often incomplete. In this contribution the generation of lift is explained in a scientific way based on the conservation principles of mass, momentum and energy and how they have to be applied to close the system of equations in order to explain the generation of lift. The most common incomplete or incorrect explanations of lift are also analysed and it is explained why they are incomplete or wrong. In this work the generation of lift is explained based on the conservation equations. It is shown how and when they apply to the problem of lift generation and how the system of equations has to be closed