Kinematics of Crystal Growth in Single‐Seal Syntaxial Veins in Limestone ‐ A Phase‐Field Study

Building on recent developments in phase-field modeling of structural diagenesis, we present an analysis of single-seal syntaxial calcite vein microstructure in a variety of limestones. We focus on the effects of fracture aperture, intergranular versus transgranular fracturing, crystal habit and the presence of second phases in the host rock, to systematically investigate a simplified set of models covering the main classes of limestone in 2D. We incorporate the kinematic process of growth competition between differently oriented crystals, growth rate anisotropy between rough and faceted crystal surfaces and different growth rates on intergranular to transgranular fractures. Results show that within the considered parameter space we can reproduce a wide range of vein microstructures in limestone known in nature, such as stretched crystals, wide-blocky veins, and elongated crystals. We identify five archetypes of vein microstructures in limestones, which are diagnostic for different kinematics and evolution of transport processes and illustrate the effect of key parameters in microstructure maps. We show how syntaxial veins with median line form after intergranular fracturing, while stretched crystals indicate transgranular fracturing. Intergranular fracturing leads to stronger growth competition and more prominent CPO in syntaxial veins. Our results can be extended to 3D to include multiple crack-seal events, pore-space cementation and simulation of fluid flow, providing a generic platform for modeling structural diagenesis in limestones

Roll-to-Roll pilot line for large-scale manufacturing of microfluidic devices

Roll-to-roll (R2R) technologies with roller-based nanoimprinting methods enable manufacturing of highly cost-effective and large-scale sheets of flexible polymer film with precise structures on a micro- and nanoscale 1. Areas that can benefit strongly from such large scale technologies are microfluidics, biosensors, and lab-on-chip products for point of care diagnostics, drug discovery and food control. Here, R2R fabrication could greatly reduce production costs and increase manufacturing capacity with respect to currently used products. A pilot line with this technology is investigated in the European Horizon 2020 project R2R Biofluidics and its capabilities are tested on two Demonstrators: - Demonstrator 1: In-vitro diagnostic chip with imprinted microfluidic channels based on optical chemiluminescence measurement by photodetectors. - Demonstrator 2: Neuronal cell culture plate with imprinted cavities and channels for controlled culturing and fluorescence imaging of neurons, for high throughput drug screening. Please click Additional Files below to see the full abstract

Robotic Stereotactic Radiosurgery in Melanoma Patients with Brain Metastases under Simultaneous Anti-PD-1 Treatment

Combination concepts of radiotherapy and immune checkpoint inhibition are currently of high interest. We examined imaging findings, acute toxicity, and local control in patients with melanoma brain metastases receiving programmed death 1 (PD-1) inhibitors and/or robotic stereotactic radiosurgery (SRS). Twenty-six patients treated with SRS alone (n = 13;20 lesions) or in combination with anti-PD-1 therapy (n = 13;28 lesions) were analyzed. Lesion size was evaluated three and six months after SRS using a volumetric assessment based on cranial magnetic resonance imaging (cMRI) and acute toxicity after 12 weeks according to the Common Terminology Criteria for Adverse Events (CTCAE). Local control after six months was comparable (86%, SRS + anti-PD-1, and 80%, SRS). All toxicities reported were less than or equal to grade 2. One metastasis (5%) in the SRS group and six (21%) in the SRS + anti-PD-1 group increased after three months, whereas four (14%) of the six regressed during further follow-ups. This was rated as pseudoprogression (PsP). Three patients (23%) in the SRS + anti-PD-1 group showed characteristics of PsP. Treatment with SRS and anti-PD-1 antibodies can be combined safely in melanoma patients with cerebral metastases. Early volumetric progression of lesions under simultaneous treatment may be related to PsP;thus, the evaluation of combined radioimmunotherapy remains challenging and requires experienced teams

Bacterial Degradation of Aromatic Compounds

Aromatic compounds are among the most prevalent and persistent pollutants in the environment. Petroleum-contaminated soil and sediment commonly contain a mixture of polycyclic aromatic hydrocarbons (PAHs) and heterocyclic aromatics. Aromatics derived from industrial activities often have functional groups such as alkyls, halogens and nitro groups. Biodegradation is a major mechanism of removal of organic pollutants from a contaminated site. This review focuses on bacterial degradation pathways of selected aromatic compounds. Catabolic pathways of naphthalene, fluorene, phenanthrene, fluoranthene, pyrene, and benzo[a]pyrene are described in detail. Bacterial catabolism of the heterocycles dibenzofuran, carbazole, dibenzothiophene, and dibenzodioxin is discussed. Bacterial catabolism of alkylated PAHs is summarized, followed by a brief discussion of proteomics and metabolomics as powerful tools for elucidation of biodegradation mechanisms