Rheology and dynamics of simple and complex liquids in mesoporous matrices

Subject of my thesis is a study of rheologic and dynamic properties of fluids confined in an isotropic pore network with pore radii of approx. 5nm embedded in a monolithic silica matrix (porous Vycor). The experimental technique bases on the capillary rise of a wetting liquid in a porous substrate, also known as spontaneous imbibition. A crucial part of the conducted experiments centers on the increasing relevance of the liquid-substrate interface in the mesopore confinement. Detailed analyses of the measurements carried out with water, silicon oils, and a series of hydrocarbons result in precise information on the boundary conditions expressed in terms of the velocity slip length. Systematic variations of the chain-length of the used hydrocarbons also allow for an assessment of the influence of the shape of the liquid\u27;s building blocks on the nanoscopic flow behavior. Supplemental forced throughput experiments additionally address the impact of the liquid-substrate interaction. Furthermore, the influences of spatial confinement on the surface freezing transition of the linear hydrocarbon n-tetracosane as well as on the mesophase transitions of the liquid crystal 8OCB are investigated. Finally, a third, more general study focuses on the kinetics of the invasion front, which is supposed to be influenced significantly by the random environment of the pore space considered.Das Themengebiet meiner Dissertation umfasst rheologische und dynamische Eigenschaften von Flüssigkeiten in einem isotropen Porennetzwerk einer monolithischen Glasmatrix (poröses Vycor). Die Porenradien betragen dabei etwa 5 nm. Die durchgeführten Experimente beruhen auf dem Prinzip des Kapillarsteigens einer benetzenden Flüssigkeit in einem porösen Substrat (spontane Imbibition). Ein Schwerpunkt der Untersuchungen liegt auf dem zunehmenden Einfluss der Grenzfläche zwischen Fluid und Substrat als Folge der extremen, räumlichen Beschränkung. Analysen der Experimente mit Wasser, Silikonölen und einer Reihe Kohlenwasserstoffe liefern präzise Angaben zur hydrodynamischen Randbedingung beschrieben durch die sog. Schlupflänge. Systematische Variationen der Kettenlänge der verwendeten Kohlenwasserstoffe erlauben die Beurteilung der Bedeutsamkeit der Molekülform für das mikroskopische Fließverhalten. Dank einer alternativen Experimentführung kann man sich auch mit dem Einfluss der Benetzbarkeit der Flüssigkeit befassen. Darüber hinaus wird der Einfluss der räumlichen Beschränkung auf Phasenübergänge behandelt. Im Speziellen werden das Oberflächengefrieren eines Alkans und die Mesophasen eines Flüssigkristalls untersucht. Schließlich wird die Aufrauung der voranschreitenden Benetzungsfront beim Kapillarsteigen in dem mesoporösen Glas untersucht. Man erwartet, dass deren Bewegung durch die zufällige Netzwerk-Topologie entscheidend beeinflusst wird

Rheologie und Dynamik von einfachen und komplexen Flüssigkeiten in mesoporösen Membranen

Subject of my thesis is a study of rheologic and dynamic properties of fluids confined in an isotropic pore network with pore radii of approx. 5nm embedded in a monolithic silica matrix (porous Vycor). The experimental technique bases on the capillary rise of a wetting liquid in a porous substrate, also known as spontaneous imbibition. A crucial part of the conducted experiments centers on the increasing relevance of the liquid-substrate interface in the mesopore confinement. Detailed analyses of the measurements carried out with water, silicon oils, and a series of hydrocarbons result in precise information on the boundary conditions expressed in terms of the velocity slip length. Systematic variations of the chain-length of the used hydrocarbons also allow for an assessment of the influence of the shape of the liquid';s building blocks on the nanoscopic flow behavior. Supplemental forced throughput experiments additionally address the impact of the liquid-substrate interaction. Furthermore, the influences of spatial confinement on the surface freezing transition of the linear hydrocarbon n-tetracosane as well as on the mesophase transitions of the liquid crystal 8OCB are investigated. Finally, a third, more general study focuses on the kinetics of the invasion front, which is supposed to be influenced significantly by the random environment of the pore space considered.Das Themengebiet meiner Dissertation umfasst rheologische und dynamische Eigenschaften von Flüssigkeiten in einem isotropen Porennetzwerk einer monolithischen Glasmatrix (poröses Vycor). Die Porenradien betragen dabei etwa 5 nm. Die durchgeführten Experimente beruhen auf dem Prinzip des Kapillarsteigens einer benetzenden Flüssigkeit in einem porösen Substrat (spontane Imbibition). Ein Schwerpunkt der Untersuchungen liegt auf dem zunehmenden Einfluss der Grenzfläche zwischen Fluid und Substrat als Folge der extremen, räumlichen Beschränkung. Analysen der Experimente mit Wasser, Silikonölen und einer Reihe Kohlenwasserstoffe liefern präzise Angaben zur hydrodynamischen Randbedingung beschrieben durch die sog. Schlupflänge. Systematische Variationen der Kettenlänge der verwendeten Kohlenwasserstoffe erlauben die Beurteilung der Bedeutsamkeit der Molekülform für das mikroskopische Fließverhalten. Dank einer alternativen Experimentführung kann man sich auch mit dem Einfluss der Benetzbarkeit der Flüssigkeit befassen. Darüber hinaus wird der Einfluss der räumlichen Beschränkung auf Phasenübergänge behandelt. Im Speziellen werden das Oberflächengefrieren eines Alkans und die Mesophasen eines Flüssigkristalls untersucht. Schließlich wird die Aufrauung der voranschreitenden Benetzungsfront beim Kapillarsteigen in dem mesoporösen Glas untersucht. Man erwartet, dass deren Bewegung durch die zufällige Netzwerk-Topologie entscheidend beeinflusst wird

Elevated markers of thrombo-inflammatory activation predict outcome in patients with cardiovascular comorbidities and COVID-19 disease: insights from the LEOSS registry

Aims: SARS-CoV-2 infection is associated with adverse outcomes in patients with cardiovascular disease. Here, we analyzed whether specific biomarkers predict the clinical course of COVID-19 in patients with cardiovascular comorbidities. Methods and results: We enrolled 2147 patients with SARS-CoV-2 infection which were included in the Lean European Open Survey on SARS-CoV‑2 (LEOSS)-registry from March to June 2020. Clinical data and laboratory values were collected and compared between patients with and without cardiovascular comorbidities in different clinical stages of the disease. Predictors for mortality were calculated using multivariate regression analysis. We show that patients with cardiovascular comorbidities display significantly higher markers of myocardial injury and thrombo-inflammatory activation already in the uncomplicated phase of COVID-19. In multivariate analysis, elevated levels of troponin [OR 1.54; (95% CI 1.22–1.96), p < 0.001)], IL-6 [OR 1.69 (95% CI 1.26–2.27), p < 0.013)], and CRP [OR 1.32; (95% CI 1.1–1.58), p < 0.003)] were predictors of mortality in patients with COVID-19. Conclusion: Patients with cardiovascular comorbidities show elevated markers of thrombo-inflammatory activation and myocardial injury, which predict mortality, already in the uncomplicated phase of COVID-19. Starting targeted anti-inflammatory therapy and aggressive anticoagulation already in the uncomplicated phase of the disease might improve outcomes after SARS-CoV-2 infection in patients with cardiovascular comorbidities

A pair of noncompeting neutralizing human monoclonal antibodies protecting from disease in a SARS-CoV-2 infection model

TRIANNI mice carry an entire set of human immunoglobulin V region gene segments and are a powerful tool to rapidly isolate human monoclonal antibodies. After immunizing these mice with DNA encoding the spike protein of SARS-CoV-2 and boosting with spike protein, we identified 29 hybridoma antibodies that reacted with the SARS-CoV-2 spike protein. Nine antibodies neutralize SARS-CoV-2 infection at IC50 values in the subnanomolar range. ELISA-binding studies and DNA sequence analyses revealed one cluster of three clonally related neutralizing antibodies that target the receptor-binding domain and compete with the cellular receptor hACE2. A second cluster of six clonally related neutralizing antibodies bind to the N-terminal domain of the spike protein without competing with the binding of hACE2 or cluster 1 antibodies. SARS-CoV-2 mutants selected for resistance to an antibody from one cluster are still neutralized by an antibody from the other cluster. Antibodies from both clusters markedly reduced viral spread in mice transgenic for human ACE2 and protected the animals from SARS-CoV-2-induced weight loss. The two clusters of potent noncompeting SARS-CoV-2 neutralizing antibodies provide potential candidates for therapy and prophylaxis of COVID-19. The study further supports transgenic animals with a human immunoglobulin gene repertoire as a powerful platform in pandemic preparedness initiatives

Status of the Horizon 2020 EuPRAXIA Conceptual Design Study

The Horizon 2020 Project EuPRAXIA (European Plasma Research Accelerator with eXcellence In Applications) is producing a conceptual design report for a highly compact and cost-effective European facility with multi-GeV electron beams accelerated using plasmas. EuPRAXIA will be set up as a distributed Open Innovation platform with two construction sites, one with a focus on beam-driven plasma acceleration (PWFA) and another site with a focus on laser-driven plasma acceleration (LWFA). User areas at both sites will provide access to FEL pilot experiments, positron generation and acceleration, compact radiation sources, and test beams for HEP detector development. Support centres in four different countries will complement the pan-European implementation of this infrastructure

HORIZON 2020 EuPRAXIA Design Study

The Horizon 2020 Project EuPRAXIA (European Plasma Research Accelerator with eXcellence In Applications) aims at producing a design report of a highly compact and cost-effective European facility with multi-GeV electron beams using plasma as the acceleration medium. The accelerator facility will be based on a laser and/or a beam driven plasma acceleration approach and will be used for photon science, high-energy physics (HEP) detector tests, and other applications such as compact X-ray sources for medical imaging or material processing. EuPRAXIA started in November 2015 and will deliver the design report in October 2019. EuPRAXIA aims to be included on the ESFRI roadmap in 2020