Are mild cleansers appropriate for hand hygiene in the COVID era? An in vitro investigation of the antiviral efficacy of different hand hygiene products

Background: Washing hands with soap and lukewarm water for 20 s is a fundamental measure advocated especially within the UK to help control the spread of viral disease. However, these practices can induce irritant contact dermatitis, particularly in healthcare professionals (HCPs). HCPs typically manage their condition by replacing soap or alcohol-based hand sanitizers with cleansers containing mild surfactants and/or emollient ingredients [skin-friendly cleansers (SFCs)] to mitigate skin damage and/or using topical emollients after washing for repair. Despite this widespread practice, there is very limited evidence supporting the efficacy of these interventions in the prevention of viral propagation. Methodology: Within this study a range of viruses comprising human coronavirus (HCoV), herpes simplex virus (HSV)-1, influenza (IVA), adenovirus (Ad), and murine norovirus (MNV) were tested against multiple hand wash products, including SFCs. In vitro analysis using plaque assays and tissue culture infectious dose 50 (TCID50) were used to assess virus infectability after incubation with the test products (soaps and SFCs) over a range of concentrations and time points. Transmission electron microscopy (TEM) was used to determine virus architecture and size, while viral replication genes were measured by reverse transcription-polymerase chain reaction (RT-PCR). Results/conclusions: Enveloped viruses demonstrated greater susceptibility over a range of test products, suggesting some SFCs are a suitable alternative to soap (depending on the presence of a viral envelope). However, no virucidal activity was observed for non-enveloped viruses. Water type (i.e., soft/hard) and pre-exposed hand hygiene conditions (i.e., clean/dirty) made little difference to the effectiveness of both soaps and SFCs. Therefore, new hand hygiene regimens should be implemented based on trying to encompass all viruses with varying structures, with specific emphasis on the absence of a viral envelope

Measurement of the collision rate coefficients between atmospheric ions and multiply charged aerosol particles in the CERN CLOUD chamber

Aerosol particles have an important role in Earth's radiation balance and climate, both directly and indirectly through aerosol–cloud interactions. Most aerosol particles in the atmosphere are weakly charged, affecting both their collision rates with ions and neutral molecules, as well as the rates by which they are scavenged by other aerosol particles and cloud droplets. The rate coefficients between ions and aerosol particles are important since they determine the growth rates and lifetimes of ions and charged aerosol particles, and so they may influence cloud microphysics, dynamics, and aerosol processing. However, despite their importance, very few experimental measurements exist of charged aerosol collision rates under atmospheric conditions, where galactic cosmic rays in the lower troposphere give rise to ion pair concentrations of around 1000 cm−3. Here we present measurements in the CERN CLOUD chamber of the rate coefficients between ions and small (&lt;10 nm) aerosol particles containing up to 9 elementary charges, e. We find the rate coefficient of a singly charged ion with an oppositely charged particle increases from 2.0 (0.4–4.4) × 10−6 cm3 s−1 to 30.6 (24.9–45.1) × 10−6 cm3 s−1 for particles with charges of 1 to 9 e, respectively, where the parentheses indicate the ±1σ uncertainty interval. Our measurements are compatible with theoretical predictions and show excellent agreement with the model of Gatti and Kortshagen (2008).</p

Chemical composition of nanoparticles from alpha-pinene nucleation and the influence of isoprene and relative humidity at low temperature

Biogenic organic precursors play an important role in atmospheric new particle formation (NPF). One of the major precursor species is alpha-pinene, which upon oxidation can form a suite of products covering a wide range of volatilities. Highly oxygenated organic molecules (HOMs) comprise a fraction of the oxidation products formed. While it is known that HOMs contribute to secondary organic aerosol (SOA) formation, including NPF, they have not been well studied in newly formed particles due to their very low mass concentrations. Here we present gas- and particle-phase chemical composition data from experimental studies of alpha-pinene oxidation, including in the presence of isoprene, at temperatures (-50 and -30 degrees C) and relative humidities (20% and 60 %) relevant in the upper free troposphere. The measurements took place at the CERN Cosmics Leaving Outdoor Droplets (CLOUD) chamber. The particle chemical composition was analyzed by a thermal desorption differential mobility analyzer (TD-DMA) coupled to a nitrate chemical ionizationatmospheric pressure interface-time-of-flight (CI-APi-TOF) mass spectrometer. CI-APi-TOF was used for particle- and gas-phase measurements, applying the same ionization and detection scheme. Our measurements revealed the presence of C8-10 monomers and C18-20 dimers as the major compounds in the particles (diameter up to similar to 100 nm). Particularly, for the system with isoprene added, C-5 (C5H10O5-7) and C-15 compounds (C15H24O5-10) were detected. This observation is consistent with the previously observed formation of such compounds in the gas phase. However, although the C-5 and C-15 compounds do not easily nucleate, our measurements indicate that they can still contribute to the particle growth at free tropospheric conditions. For the experiments reported here, most likely isoprene oxidation products enhance the growth of particles larger than 15 nm. Additionally, we report on the nucleation rates measured at 1.7 nm (J(1.7 nm)) and compared with previous studies, we found lower J(1.7 nm) values, very likely due to the higher alpha-pinene and ozone mixing ratios used in the present study.Peer reviewe

Chronic Pruritus and Connective Tissue Disorders: Review, Gaps, and Future Directions

Chronic itch is a common skin manifestation in many connective tissue diseases. However, the cause of chronic itch in these diseases is still not fully understood. The complex, and in some cases incomplete understanding of, pathogenesis in each condition makes it difficult to target specific mediators of chronic itch. It is important to better understand the pathophysiology of chronic itch in these conditions, as this information might provide a fuller understanding of the pathogenesis of the diseases in general and lead to the development of more specific treatments for connective tissue diseases in patients with chronic itch. We present a review of the literature on what is known about the prevalence, possible pathophysiology, and effect on quality of life of chronic itch in patients with scleroderma, Sjögren’s syndrome, dermatomyositis, systemic lupus erythematosus, cutaneous lupus erythematosus, and mixed connective tissue disease