Publications by Kalliopi Violaki

Atmospheric reactive nitrogen and its dry deposition regimes under anthropogenic influence: Insights from intensive and long-term monitoring in Switzerland

Athanasios Nenes, Andrea Baccarini, Kalliopi Violaki, Ghislain Gilles Jean-Michel Motos

Excessive nitrogen deposition from anthropogenic activities poses significant challenges to ecosystems and air quality.1 The atmospheric deposition of ammonium and nitrate plays a critical role in regulating ecosystem productivity and driving particulate m ...

2025

Comparative characterization of bronchial and nasal mucus reveals key determinants of influenza A virus inhibition

Athanasios Nenes, Tamar Kohn, Kalliopi Violaki, Ghislain Gilles Jean-Michel Motos, Walter Hugentobler, Céline Terrettaz, Aline Laetitia Schaub

Differentiated primary human respiratory epithelial cells grown at air-liquid interface have become a widely used cell culture model of the human conducting airways. These cultures contain secretory cells such as goblet and club cells, which produce and se ...

American Society for Microbiology2025

Solid-state 31P NMR reveals the biological organophosphorus compounds as the dominant phosphorus species in Saharan dust aerosols

Athanasios Nenes, Pierre Rossi, Kalliopi Violaki, Christos Panagiotopoulos, Claudia Esther Avalos

Phosphorus is a critical nutrient affecting primary productivity across all ecosystems. Many regions worldwide are limited or co-limited by phosphorus availability, which can be alleviated through atmospheric deposition. Dust is known to be a key external ...

2025

Phosphorus speciation in environmental organic matter using 31P-NMR. Recent advances in the characterization of atmospheric organic matter

Athanasios Nenes, Kalliopi Violaki, Christos Panagiotopoulos

Phosphorus (P) is a vital element for all living organisms and is one of the most essential nutrients in both aquatic and terrestrial ecosystems. As a fundamental component of DNA and RNA, it plays a structural role in cell membranes (e.g., as part of phos ...

2025

Stability of influenza A virus in droplets and aerosols is heightened by the presence of commensal respiratory bacteria

Tamar Kohn, Athanasios Nenes, Ghislain Gilles Jean-Michel Motos, Htet Kyi Wynn, Kalliopi Violaki, Céline Terrettaz, Aline Laetitia Schaub, Walter Hugentobler, Shannon Christa David, Laura José Costa Henriques

Aerosol transmission remains a major challenge for control of respiratory viruses, particularly those causing recurrent epidemics, like influenza A virus (IAV). These viruses are rarely expelled alone, but instead are embedded in a consortium of microorgan ...

American Society for Microbiology2024

Dependence of aerosol-borne influenza A virus infectivity on relative humidity and aerosol composition

Athanasios Nenes, Tamar Kohn, Kalliopi Violaki, Ghislain Gilles Jean-Michel Motos, Walter Hugentobler, Céline Terrettaz, Aline Laetitia Schaub, Shannon Christa David, Laura José Costa Henriques

We describe a novel biosafety aerosol chamber equipped with state-of-theart instrumentation for bubble-bursting aerosol generation, size distribution measurement, and condensation-growth collection to minimize sampling artifacts when measuring virus infect ...

Frontiers Media SA2024

Salt Supersaturation as an Accelerator of Influenza A Virus Inactivation in 1 μL Droplets

Athanasios Nenes, Tamar Kohn, Kalliopi Violaki, Ghislain Gilles Jean-Michel Motos, Walter Hugentobler, Céline Terrettaz, Laura José Costa Henriques

Influenza A virus (IAV) spreads through exhaled aerosol particles and larger droplets. Estimating the stability of IAV is challenging and depends on factors such as the respiratory matrix and drying kinetics. Here, we combine kinetic experiments on millime ...

2024

Drivers of droplet formation in east Mediterranean orographic clouds

Kalliopi Violaki, Ghislain Gilles Jean-Michel Motos, Kunfeng Gao

The purpose of this study is to understand the drivers of cloud droplet formation in orographic clouds. We used a combination of modeling, in situ, and remote sensing measurements at the high-Altitude Helmos Hellenic Atmospheric Aerosol and Climate Change ...

Copernicus Publications2024

Impact of organic compounds on the stability of influenza A virus in deposited 1-μL droplets

Athanasios Nenes, Tamar Kohn, Kalliopi Violaki, Ghislain Gilles Jean-Michel Motos, Walter Hugentobler, Céline Terrettaz, Aline Laetitia Schaub, Shannon Christa David

The composition of respiratory fluids influences the stability of viruses in exhaled aerosol particles and droplets, though the role of respiratory organics in modulating virus stability remains poorly understood. This study investigates the effect of orga ...

2024

Inactivation mechanisms of influenza A virus under pH conditions encountered in aerosol particles as revealed by whole-virus HDX-MS

Athanasios Nenes, Tamar Kohn, Giovanni D'Angelo, Kalliopi Violaki, Ghislain Gilles Jean-Michel Motos, Aline Laetitia Schaub, Walter Hugentobler, Shannon Christa David, Jonathan Paz Montoya

Multiple respiratory viruses, including influenza A virus (IAV), can be transmitted via expiratory aerosol particles, and aerosol pH was recently identified as a major factor influencing airborne virus infectivity. Indoors, small exhaled aerosols undergo r ...

2023