Interaction of light with gas-liquid interfaces: influence on photon absorption in continuous-flow photoreactors.

Light interacts with gas bubbles in various ways, potentially leading to photon losses in gas-liquid photochemical applications. Given that light is a valuable 'reagent', understanding these losses is crucial for optimizing reactor efficiency. In this study, we address the challenge of quantifying these interactions by implementing a method that separately determines the photon flux and utilizes actinometric experiments to determine the effective optical path length, a key descriptor of photon absorption.

Interferon restores replication fork stability and cell viability in BRCA-defective cells via ISG15.

DNA replication and repair defects or genotoxic treatments trigger interferon (IFN)-mediated inflammatory responses. However, whether and how IFN signaling in turn impacts the DNA replication process has remained elusive. Here we show that basal levels of the IFN-stimulated gene 15, ISG15, and its conjugation (ISGylation) are essential to protect nascent DNA from degradation.

Scale-Up of a Heterogeneous Photocatalytic Degradation Using a Photochemical Rotor-Stator Spinning Disk Reactor.

Many chemical reactions contain heterogeneous reagents, products, byproducts, or catalysts, making their transposition from batch to continuous-flow processing challenging. Herein, we report the use of a photochemical rotor-stator spinning disk reactor (pRS-SDR) that can handle and scale solid-containing photochemical reaction conditions in flow. Its ability to handle slurries was showcased for the TiO-mediated aerobic photodegradation of aqueous methylene blue.

SMARCAD1-mediated active replication fork stability maintains genome integrity.

The stalled fork protection pathway mediated by breast cancer 1/2 (BRCA1/2) proteins is critical for replication fork stability. However, it is unclear whether additional mechanisms are required to maintain replication fork stability. We describe a hitherto unknown mechanism, by which the SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily-A containing DEAD/H box-1 (SMARCAD1) stabilizes active replication forks, that is essential to maintaining resistance towards replication poisons.

More end resection is not merrier.

Unrestrained 53BP1 activity causes fusions of dysfunctional telomeres and embryonic lethality associated with misrepair of DNA double-strand breaks in BRCA1-deficient mice. However, the physiological role of 53BP1 remains unclear, because it presumably did not evolve to carry out these pathological functions. A new report proposes that 53BP1 activity prevents hyper-resection and thereby promotes error-free DNA repair while suppressing alternative mutagenic pathways.

Visualization and interpretation of eukaryotic DNA replication intermediates in vivo by electron microscopy.

The detailed understanding of the DNA replication process requires structural insight. The combination of psoralen cross-linking and electron microscopy has been extensively exploited to reveal the fine architecture of in vivo DNA replication intermediates. This approach proved instrumental to uncover the basic mechanisms of DNA duplication, as well as the perturbation of this process by various forms of replication stress.