SARS-CoV-2 risk assessment for a 30-minute car journey

In this paper a numerical methodology for close proximity exposure (<2m) is applied to the analysis of aerosol airborne dispersion and SARS-CoV-2 potential infection risk during short journeys in passenger cars. It consists of a three-dimensional transient Eulerian-Lagrangian numerical model coupled with a recently proposed SARS-CoV-2 emission approach, using the open-source software OpenFOAM. The numerical tool, validated by Particle Image Velocimetry (PIV), is applied to the simulation of aerosol droplets emitted by a contagious subject in a car cabin during a 30-minute journey and to the integrated risk assessment for SARS-CoV-2 for the other passengers. The effects of different geometrical and thermo-fluid-dynamic influence parameters are investigated, showing that both the position of the infected subject and the ventilation system design affect the amount of virus inhaled and the highest-risk position inside the passenger compartment. Calculated infection risk, for susceptible passengers in the car, can reach values up to 59%. © 2022 17th International Conference on Indoor Air Quality and Climate, INDOOR AIR 2022. All rights reserved.

Application of Convolutional Neural Network techniques to the classification of lung illnesses

The heterotypic perspective of cancer depicts solid tumors as ecosystems composed of aberrant epithelium tumor cells and a multitude of cell types together referred to as stromal cells. Macrophages, which are innate immune cells, are overrepresented in certain environments. Tumor-associated macrophages (TAMs) are macrophages found in the tumor microenvironment;they are derived from the blood's monocytes and are essential for tumor progression. TAMs acquiring tumorigenic qualities is dependent on a complicated interaction between TAMs and tumor cells. Using co-culture studies, we showed that tumor-derived secretory signals promote Tams' tumor-promoting characteristics, shaping up Tams' features in ways that are advantageous to the tumor. When model human monocytes (THP-1) were co-cultured with A549 cells, the A549 cells exhibited increased proliferation, migration, and invasiveness due to the secretion of tumor-promoting cytokines from the THP-1 cells. We showed that EDA-containing Fibronectin secreted by A549 cells reliably mediates the pro-inflammatory response of THP-1 monocytes in a paracrine manner. Ablation of such responses by the treatment of THP-1 cells with TLR-4 blocking antibody implicated Fibronectin-TLR4 axis in tumor-associated inflammation and suggests a paradigm wherein lung carcinoma cell derived EDA-containing Fibronectin drives a pro-inflammatory and pro-metastatic tumor microenvironment. Interestingly, autocrine proliferation, migration, and invasion were all boosted by EDA-containing Fibronectin secreted by A549 cells. Lastly, we demonstrated that the EDA in Fibronectin activates the epithelial-mesenchymal transition pathway in A549 cells, hence granting these cells the ability to metastasize. © 2023 IEEE.

Building Blood Vessel Chips with Enhanced Physiological Relevance

Blood vessel chips are bioengineered microdevices, consisting of biomaterials, human cells, and microstructures, which recapitulate essential vascular structure and physiology and allow a well-controlled microenvironment and spatial-temporal readouts. Blood vessel chips afford promising opportunities to understand molecular and cellular mechanisms underlying a range of vascular diseases. The physiological relevance is key to these blood vessel chips that rely on bioinspired strategies and bioengineering approaches to translate vascular physiology into artificial units. Here, several critical aspects of vascular physiology are discussed, including morphology, material composition, mechanical properties, flow dynamics, and mass transport, which provide essential guidelines and a valuable source of bioinspiration for the rational design of blood vessel chips. The state-of-art blood vessel chips are also reviewed that exhibit important physiological features of the vessel and reveal crucial insights into the biological processes and disease pathogenesis, including rare diseases, with notable implications for drug screening and clinical trials. It is envisioned that the advances in biomaterials, biofabrication, and stem cells improve the physiological relevance of blood vessel chips, which, along with the close collaborations between clinicians and bioengineers, enable their widespread utility. © 2023 Wiley-VCH GmbH.

Navigating the cellular landscape in tissue: Recent advances in defining the pathogenesis of human disease.

Over the past decade, our understanding of human diseases has rapidly grown from the rise of single-cell spatial biology. While conventional tissue imaging has focused on visualizing morphological features, the development of multiplex tissue imaging from fluorescence-based methods to DNA- and mass cytometry-based methods has allowed visualization of over 60 markers on a single tissue section. The advancement of spatial biology with a single-cell resolution has enabled the visualization of cell-cell interactions and the tissue microenvironment, a crucial part to understanding the mechanisms underlying pathogenesis. Alongside the development of extensive marker panels which can distinguish distinct cell phenotypes, multiplex tissue imaging has facilitated the analysis of high dimensional data to identify novel biomarkers and therapeutic targets, while considering the spatial context of the cellular environment. This mini-review provides an overview of the recent advancements in multiplex imaging technologies and examines how these methods have been used in exploring pathogenesis and biomarker discovery in cancer, autoimmune and infectious diseases.

Pathogenic microorganism monitoring and traceability exploration of medical waste disposal routes in children's hospital

OBJECTIVE: Due to the lack of effective monitoring of microbial spectrum of medical waste collection, transport, storage and transfer path, as well as the evaluation of disinfection effects in medical institutions, this study aimed to explore the microenvironment, prevention and control difficulties and management opinions of medical waste disposal path through the microbial analysis of the medical waste disposal path in model departments. METHODS According to the standard process, the environmental samples at different time periods before and after the disinfection of the medical waste disposal path in the model department were collected and analyzed. The drug resistance and molecular typing traceability of important pathogens were analyzed. And the dynamic effect of the whole path application of the disinfection scheme for medical waste disposal in the model department were evaluated. Efficient frequency and application effect of disinfection of and hygiene of relevant places and gloves were evaluated through environmental monitoring before and after disinfection. RESULTS Most of the isolated strains were environmental microorganisms, Acinetobacter baumannii, Pseudomonas aeruginosa, Streptococcus pneumoniae, Enterococcus faecalis and Enterococcus faecium were also isolated, and a multidrug-resistant A. baumannii strain was identified. Through typing and tracing the source, the multiple strains of A. Baumannii were found to be of different genetic origins and the two strains were from the same clonal line. Using original detection technology, no contamination of Salmonella and Shigella was found in the path. The new coronavirus and norovirus were not detected. However, the environmental pollution of rotavirus was obvious. CONCLUSION The risk of random transmission of rotavirus cannot completely solved by existing hand-sterilized regents. Timely or even frequent replacement of gloves is a simple solution in the workflow. The sterilized medical waste transfer vehicles are likely to become the pollution source of rotavirus after passing through a certain medical waste path. The medical waste disposal personnel should replace the rotating vehicle in time before entering other wards. In addition, due to the weak professional ability of cleaners, simple and easy process guidelines is the most effective solution at present.

Analysis of GLRLM Texture Features Derived From Computed Tomography Scans For COVID-19 Diagnosis

Since its discovery in late 2019, COVID-19 has become a major worldwide concern due to its incredibly high degree of contagion, and early diagnosis is crucial to limit this global progression. Computed Tomography (CT) scans of the chest offer a low-cost alternative diagnosis modality to the standard reverse polymerase chain reaction (RT-PCR) test for COVID-19. In this paper, we analyze texture features extracted from chest CT scans using Gray Level Run Length Matrix (GLRLM) techniques for their ability to distinguish between COVID-19 and non-COVID-19 patients. Quantitative texture analysis of CT scans provides a measure of the biological heterogeneity in tissue microenvironment which can be useful in the diagnosis of a wide range of diseases, and we hypothesize that GLRLM texture features may hold significance for diagnosis of COVID-19. 13 GLRLM features were extracted from CT scans of 349 positive COVID-19 cases and 397 negative COVID-19 cases. Holdout validation was used to randomly split 70% of the images for training, and the remaining 30% for testing. A GentleBoost classifier was used to evaluate performance. A significant AUROC of 0.92 along with a high classification accuracy of 85.7% was obtained on the independent test set, indicating that GLRLM texture features extracted from chest CT scans have the potential to be a significant tool in the rapid and accurate diagnosis of COVID-19. © 2021 IEEE.

Training can't always lead to Olympic macrophages

Although the memory capacity of innate immune cells, termed trained immunity (TI), is a conserved evolutionary trait, the cellular and molecular mechanisms involved are incompletely understood. One fundamental question is whether the induction of TI generates a homogeneous or heterogeneous population of trained cells. In this issue of theJCI, Zhang, Moorlag, and colleagues tackle this question by combining an in vitro model system of TI with single-cell RNA sequencing. The induction of TI in human monocytes resulted in three populations with distinct transcriptomic profiles. Interestingly, the presence of lymphocytes in the microenvironment of monocytes substantially impacted TI. The authors also identified a similar population of monocytes in various human diseases or in individuals vaccinated with bacillus Calmette-Guérin. These insights warrant in-depth analysis of TI in responsive versus nonresponsive immune cells and suggest that modulating TI may provide a strategy for treating infections and inflammatory diseases.

The nexus between in-car aerosol concentrations, ventilation and the risk of respiratory infection.

We examined the trade-offs between in-car aerosol concentrations, ventilation and respiratory infection transmission under three ventilation settings: windows open (WO); windows closed with air-conditioning on ambient air mode (WC-AA); and windows closed with air-conditioning on recirculation (WC-RC). Forty-five runs, covering a total of 324 km distance on a 7.2-km looped route, were carried out three times a day (morning, afternoon, evening) to monitor aerosols (PM2.5; particulate matter < 2.5 µm and PNC; particle number concentration), CO2 and environmental conditions (temperature and relative humidity). Ideally, higher ventilation rates would give lower in-car pollutant concentrations due to dilution from outdoor air. However, in-car aerosol concentrations increased with ventilation (WO > WC-AA > WC-RC) due to the ingress of polluted outdoor air on urban routes. A clear trade-off, therefore, exists for the in-car air quality (icAQ) versus ventilation; for example, WC-RC showed the least aerosol concentrations (i.e. four-times lower compared with WO), but corresponded to elevated CO2 levels (i.e. five-times higher compared with WO) in 20 mins. We considered COVID-19 as an example of respiratory infection transmission. The probability of its transmission from an infected occupant in a five-seater car was estimated during different quanta generation rates (2-60.5 quanta hr-1) using the Wells-Riley model. In WO, the probability with 50%-efficient and without facemasks under normal speaking (9.4 quanta hr-1) varied only by upto 0.5%. It increased by 2-fold in WC-AA (<1.1%) and 10-fold in WC-RC (<5.2%) during a 20 mins trip. Therefore, a wise selection of ventilation settings is needed to balance in-car exposure in urban areas affected by outdoor air pollution and that by COVID-19 transmission. We also successfully developed and assessed the feasibility of using sensor units in static and dynamic environments to monitor icAQ and potentially infer COVID-19 transmission. Further research is required to develop automatic-alarm systems to help reduce both pollutant exposure and infection from respiratory COVID-19 transmission.