Herpes simplex virus type 1 (HSV-1) remodels the host chromatin structure and induces a host-to-virus transcriptional switch during lytic infection. We combine super-resolution imaging and chromosome-capture technologies to identify the mechanism of remodeling. We show that the host chromatin undergoes massive condensation caused by the hijacking of RNA polymerase II (RNAP II) and topoisomerase I (TOP1). In addition, HSV-1 infection results in the rearrangement of topologically associating domains and loops, although the A/B compartments are maintained in the host. The position of viral genomes and their association with RNAP II and cohesin is determined nanometrically. We reveal specific host–HSV-1 genome interactions and enrichment of upregulated human genes in the most contacting regions. Finally, TOP1 inhibition fully blocks HSV-1 infection, suggesting possible antiviral strategies. This viral mechanism of host chromatin rewiring sheds light on the role of transcription in chromatin architecture.

Highly transparent optical surfaces with antireflection (AR) properties have the potential to increase the performance of a wide range of applications, such as windows for photovoltaic cells, photodetectors, and display screens among others. Biomimetic structures inspired by the moth-eye have attracted much attention as they can offer superior AR properties, which can generate broadband, omnidirectional optical transmission, and water-repellent self-cleaning behavior. However, many biomimetic surfaces suffer from time-consuming and complex processing, for example, electron beam and nanoimprint lithography, and/or sub-optimal mechanical reliability. In this paper, we introduce a hybrid material approach—nanostructured polyimide on a substrate—for demonstrating a surface with significant AR and hydrophobic properties together with low scattering (haze) and high mechanical resistance. As an example of applications, we demonstrate an indium tin oxide transparent conductive substrate with a large AR effect and optical transmission associated to the nanostructured polyimide coating. The proposed design and method based on conventional spin-coating and lithography-free metal dewetting have the potential to be a low-cost processing path of nanostructured AR transparent substrates.

Photodissolution is a process that is well known for its ability to cause inclusion of silver into the matrix of a chalcogenide layer, changing its optical properties. In this paper, using e-beam deposition, we developed Ag (74 nm)/As₂S₃ (355 nm) bilayers and characterized the photodissolution kinetics when exposed to actinic radiation. We showed that local complete silver photodissolution at the micron scale can be achieved. Based on this result, we then developed amplitude-based computer-generated holograms using direct laser writing. CW lasers with beam shaping and short pulse lasers with beam scanning were both implemented. Elements with 8.5 µm and <1 µm spatial resolution and close to theoretical intensity distribution, respectively, were successfully demonstrated.

Chromatin organizes in a highly hierarchical manner that affects gene regulation. While many discoveries in the field have been driven by genomic techniques, super-resolution microscopy has proved to be an essential method to fully understand folding in single cells. In this article we summarize the main strategies to probe chromatin architecture using single-molecule localization microscopy and some of the key findings this has enabled. We specifically focus on the recent developments in techniques using oligonucleotide libraries and how their versatility drives multiplexing. These multiplexed libraries allow to super-resolve architectural proteins, DNA folding and transcription. We compare the latest results in this field and reflect about the future of these methods.