SARS-CoV-2 infection (COVID-19) in children.

Since the outbreak in December 2019, the SARS-CoV-2 pandemic virus has been a major public health problem in all countries of the world. The virus is transmitted by inhalation of respiratory droplets from the patient or asymptomatic carrier and is highly contagious. The clinical disease in children is similar to any acute respiratory infection with predominant upper respiratory symptoms, but occasionally can progress to pneumonia with acute respiratory distress syndrome and multiorgan failure. The disease is milder in children than in adults, with low mortality, and it appears that infants and young children have a somewhat more severe clinical course. Diagnosis is made by detecting the virus from respiratory samples (mainly nasopharyngeal and oropharyngeal swabs) using polymerase chain reaction. Treatment is usually symptomatic, and in severe and critical forms, the use of one of the antiviral drugs (lopinavir-ritonavir, remdesivir, hydroxychloroquine) may be consideredCopyright © 2020 Croatian Paediatric Society. All rights reserved.

A droplet digital PCR chip with passive bubble removal for absolute nucleic acid quantification

Droplet digital polymerase chain reaction (ddPCR) is an extremely sensitive method for the precisely determining the concentration of target nucleic acids. However, air bubbles between droplets during amplification can cause significant droplet loss and decreased accuracy in results. In the present study, an all-in-one microfluidic chip that integrates emulsification, passive bubble removal, droplet monolayer storage, on-chip nucleic acid amplification, and droplet fluorescence signal readout is proposed. The integrated passive bubble removal structures automatically complete the trapping and guiding of the bubbles, ensuring that the droplets do not touch the bubbles during amplification and thus is not lost. The ddPCR device with optimized key parameters proved to be effective and efficient by completely removing bubbles between droplets and having a dead volume of less than 1 %. The ability of the ddPCR chip to accurately quantify nucleic acids was evaluated by measuring plasmids with the SARS-CoV-2N gene at concentrations ranging from 10 to 50 000 copies/μL. The innovative ddPCR device satisfies the requirement for accurate nucleic acid quantification and is expected to accelerate the popularity of dPCR due to its low processing difficulty, ease of use and high robustness.

Effect of Elevator Design on the Risk Associated with COVID Transmission – A Comparative Study between a Sliding Door and a Collapsible Gate Elevator

The ominous spread of the COVID-19 pandemic is attributed to the droplets respired during coughing, sneezing or speaking. These droplets undergo evaporation to become aerosols, which, along with the larger droplets, are believed to ultimately spread the virus. In this current work, a small, enclosed region like an elevator (containing a COVID infected passenger) is considered where the risk of infection is high as the commonly practiced norm of social distancing is not possible. Numerical simulations are performed using OpenFOAM. Two different types of elevators – one equipped with a sliding door and the other with a collapsible gate, are considered and the change in droplet behavior is examined. Certain parameters pertaining to the risk of virus transmission have been quantified and assessed thoroughly, such as the percentage of droplets floating in the height range from a person's waist height to his mouth height, the radial span of the floating droplets from the infected passenger's mouth. From these parameters, the safety measures to be adopted by other copassengers can be determined. After an extensive study, it has been found that the collapsible gate elevator is safer than the sliding door elevator along with added advantages in the context of disease transmission. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

Large eddy simulation of sneeze plumes and particles in a poorly ventilated outdoor air condition: A case study of the University of Houston main campus.

Since the outbreak of the COVID-19 pandemic, many previous studies using computational fluid dynamics (CFD) have focused on the dynamics of air masses, which are believed to be the carriers of respiratory diseases, in enclosed indoor environments. Although outdoor air may seem to provide smaller exposure risks, it may not necessarily offer adequate ventilation that varies with different micro-climate settings. To comprehensively assess the fluid dynamics in outdoor environments and the efficiency of outdoor ventilation, we simulated the outdoor transmission of a sneeze plume in "hot spots" or areas in which the air is not quickly ventilated. We began by simulating the airflow over buildings at the University of Houston using an OpenFOAM computational fluid dynamics solver that utilized the 2019 seasonal atmospheric velocity profile from an on-site station. Next, we calculated the length of time an existing fluid is replaced by new fresh air in the domain by defining a new variable and selecting the hot spots. Finally, we conducted a large-eddy simulation of a sneeze in outdoor conditions and then simulated a sneeze plume and particles in a hot spot. The results show that fresh incoming air takes as long as 1000 s to ventilate the hot spot area in some specific regions on campus. We also found that even the slightest upward wind causes a sneeze plume to dissipate almost instantaneously at lower elevations. However, downward wind provides a stable condition for the plume, and forward wind can carry a plume even beyond six feet, the recommended social distance for preventing infection. Additionally, the simulation of sneeze droplets shows that the majority of the particles adhered to the ground or body immediately, and airborne particles can be transported more than six feet, even in a minimal amount of ambient air.

The role of the oral cavity in SARS-CoV-2- and other viral infections.

OBJECTIVE: This study aims to review the role of the oral cavity in SARS-CoV-2- and other viral upper respiratory tract infections. MATERIAL AND METHODS: Data reviewed in the text have been researched online and also reflect personal expertise. RESULTS: Numerous respiratory and other viruses replicate in the oral cavity and are transmitted via aerosols (< 5 µm) and droplets (> 5 µm). SARS-CoV-2 replication has been documented in the upper airways as well as in oral mucosa and salivary glands. These sites are also virus reservoirs that can infect other organs, e.g., the lungs and gastrointestinal tract, as well as other individuals. Laboratory diagnosis of viruses in the oral cavity and upper airways focuses on real-time PCR; antigen tests are less sensitive. For screening and monitoring infections, nasopharyngeal and oral swabs are tested; saliva is a good and more comfortable alternative. Physical means like social distancing or masks have been proven successful to reduce the risk of infection. Both wet-lab and clinical studies confirm that mouth rinses are effective against SARS-CoV-2 and other viruses. Antiviral mouth rinses can inactivate all viruses that replicate in the oral cavity. CONCLUSIONS: The oral cavity plays an important role in viral infections of the upper respiratory tract: it serves as a portal of entry, a site of replication, and a source of infection by droplets and aerosols. Physical means but also antiviral mouth rinses can help reduce the spread of viruses and contribute to infection control.

Ventilation strategies based on an aerodynamic analysis during a large-scale SARS-CoV-2 outbreak in an acute-care hospital.

BACKGROUND: This study aimed to investigate ventilation strategies to prevent nosocomial transmission of coronavirus disease 2019 (COVID-19). METHODS: We conducted a retrospective epidemiological investigation of a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak in a teaching hospital (February-March 2021). The largest outbreak ward was studied, and measurements were taken to determine the pressure difference and air change per hour (ACH) of the rooms. Airflow dynamics were assessed using an oil droplet generator, indoor air quality sensor, and particle image velocimetry in the index patient's room, corridor, and opposite rooms, by varying the opening and closing of windows and doors. RESULTS: During the outbreak, 283 COVID-19 cases were identified. The SARS-CoV-2 spread occurred sequentially from the index room to the nearest room, especially the opposite. The aerodynamic study demonstrated that droplet-like particles in the index room diffused through the corridor and the opposite room through the opening door. The mean ACH of the rooms was 1.44; the air supply volume was 15.9% larger than the exhaust volume, forming a positive pressure. Closing the door prevented diffusion between adjacent rooms facing each other, and natural ventilation reduced the concentration of particles within the ward and minimised their spread to adjacent rooms. CONCLUSIONS: Spread of droplet-like particles between rooms could be attributed to the pressure difference between the rooms and corridor. To prevent spread of SARS-CoV-2 between rooms, increasing the ACH in the room by maximising ventilation and minimising the positive pressure through supply/exhaust control and closing the room door are essential.

Knowledge, attitude, and practice towards COVID-19 among students in Kirkuk Medical College, Iraq

On March 11, 2020, the World Health Organization (WHO) designated the new coronavirus COVID-19 to be epidemic. Adherence to infection control methods is strongly affected by an individual's knowledge, attitudes, and practices (KAP). The study aimed to evaluate medical students' understanding, and attitudes toward COVID-19 at the Kirkuk Medical College in Iraq. From October 16 to October 26, 2020, a cross-sectional online study was conducted, among a sample of students in Kirkuk Medical College, one of the Iraqi governorates. A total of 214 students were included in this research, and the age varied between 20-25 years. The questionnaire was divided into demographic data, knowledge, attitudes, and practices, modified from an online questionnaire regarding COVID-19 previously used. Descriptive statistics and t-tests were conducted. Among the study sample (n=214), age ranged between 20-25 years, 72.9% were females, and 86.9% resided in urban areas. The learning questionnaire's total accuracy rate was 96.3%. 98.1% of the students know that the virus is spreading by respiratory droplets from infected individuals, 30.4% have a good attitude towards COVID-19, and 100% have good practice dodging crowded places and practicing appropriate hand hygiene. The majority of students are knowledgeable of disease transference prevention and good practices. Female gender and urban residency play a positive role in knowledge and practice in respect to COVID-19 but not in what concerns the attitude. It is recommended to continue health education programs to correct the negative attitude among students, especially those who reside in rural areas.Copyright © 2023, Codon Publications. All rights reserved.

Coronaviral ORF6 protein mediates inter-organelle contacts and modulates host cell lipid flux for virus production.

Lipid droplets (LDs) form inter-organelle contacts with the endoplasmic reticulum (ER) that promote their biogenesis, while LD contacts with mitochondria enhance ß-oxidation of contained fatty acids. Viruses have been shown to take advantage of lipid droplets to promote viral production, but it remains unclear whether they also modulate the interactions between LDs and other organelles. Here, we showed that coronavirus ORF6 protein targets LDs and is localized to the mitochondria-LD and ER-LD contact sites, where it regulates LD biogenesis and lipolysis. At the molecular level, we find that ORF6 inserts into the LD lipid monolayer via its two amphipathic helices. ORF6 further interacts with ER membrane proteins BAP31 and USE1 to mediate ER-LDs contact formation. Additionally, ORF6 interacts with the SAM complex in the mitochondrial outer membrane to link mitochondria to LDs. In doing so, ORF6 promotes cellular lipolysis and LD biogenesis to reprogram host cell lipid flux and facilitate viral production.

Lipid Droplets from Plants and Microalgae: Characteristics, Extractions, and Applications.

Plant and algal LDs are gaining popularity as a promising non-chemical technology for the production of lipids and oils. In general, these organelles are composed of a neutral lipid core surrounded by a phospholipid monolayer and various surface-associated proteins. Many studies have shown that LDs are involved in numerous biological processes such as lipid trafficking and signaling, membrane remodeling, and intercellular organelle communications. To fully exploit the potential of LDs for scientific research and commercial applications, it is important to develop suitable extraction processes that preserve their properties and functions. However, research on LD extraction strategies is limited. This review first describes recent progress in understanding the characteristics of LDs, and then systematically introduces LD extraction strategies. Finally, the potential functions and applications of LDs in various fields are discussed. Overall, this review provides valuable insights into the properties and functions of LDs, as well as potential approaches for their extraction and utilization. It is hoped that these findings will inspire further research and innovation in the field of LD-based technology.

Exhaled Aerosols in PCR-confirmed SARS-CoV-2-infected Children

Background Available data on aerosol emisions in children and adolescents during spontaneous breathing are limited. Our aim was to gain insight into the role of children in the spread of SARS-CoV-2 and whether aerosol measurements in children can be used to help detect so-called superspreaders - infected individuals with extremely high numbers of exhaled aerosol particles. Methods In this prospective study, the aerosol concentration of SARS-CoV-2 PCR-positive and SARS-CoV-2 PCR-negative children and adolescents (2-17 years) was investigated. All subjects were asked about their current health status and medical history. The exhaled aerosol particle counts of PCR-negative and PCR-positive subjects were measured using the Resp-Aer-Meter (Palas GmbH, Karlsruhe, Germany) and compared using linear regresion. The study was registered in the German Register of Clinical Studies (DRKS), DRKS00028539. Results A total of 250 children and adolescents were included in the study, 105 of whom were SARS-CoV-2 positive and 145 of whom were SARS-CoV-2 negative. The median age acros both groups was nine years (IQR 7-11). A total of 124 (49.6%) participants were female, and 126 (50.4%) participants were male. A total of 81.9% of the SARS-CoV-2-positive group had symptoms of viral infection. The median particle count of all individuals was 79.55 p/l (IQR 44.55-141.15). There was a tendency for older children to exhale more particles (1-5 years: 79.54 p/l;6-11 years: 77.96 p/l;12-17 years: 98.63 p/l). SARS-CoV-2 PCR status was not a bivariate predictor (t=.82, p=.415) for the exhaled aerosol particle count;however, the SARS-CoV-2 status was shown to be a significant predictor in a multiple regresion model together with age, body mas index (BMI), covid vaccination, and past SARS-CoV-2 infection (t=.2.81 p=.005). Covid vaccination status was a highly significant predictor of exhaled aerosol particles (p <.001).Conclusion During SARS-CoV-2 infection, children and adolescents do not have elevated aerosol levels. In addition, no superspreaders were found. Children and adolescents are not the main driver of the SARS-CoV-2 pandemic. .

Coronavirus Disease (COVID-19) Possible Transmission Routes and Alleviation Strategies

Coronavirus disease is a contagious respiratory ailment that has spread significantly around the world. Most cases of COVID-19 are spread from person to person by coming into contact with respiratory droplets that are released when an infected person coughs or sneezes. In this manuscript, we have highlighted the possible transmission of COVID-19 through food, water, air and paper. In the case of food, we have extensively covered the transmission of COVID-19 through meat, frozen foods, food packaging and food market along with the incidences worldwide. In the nextsection, we have highlighted the different components of air which are responsible for the transmission and also covered its relation with PM 2.5 incidence. The SARS-CoV-2 was isolated from sewage water/wastewater of various countries namely the United States, India, Australia, Netherlands and France signifying that wastewater can be a mode of virus transmission. The paper circulation by the infected COVID-19 patients can also be a virus conveyance route. It can be concluded that SARS-CoV-2 can therefore be transmitted indirectly through food via the workers involved in food packing or food marts.By following general safety precautions (wearing masks, using hand sanitisers, cleaning and disinfecting contact surfaces, and avoiding close contact), heating and using chemicals like ethanol (67-71%), sodium hypochlorite (0.1%) and hydrogen peroxide (0.5%) on environmental surfaces, along with vaccination, it is possible to reduce the spread of the SARS-CoV-2 virus.Copyright © 2023 The International Journal of Pharmaceutical Research and Allied Sciences (IJPRAS).

Neuroradiological Findings in Headache Patients After COVID-19 Infection

The new coronavirus disease was declared by WHO as COVID-19 1 and the name of the virus causing this disease was defined as SARS-CoV-2 . The most common way of transmission of the virus is the close contact with infected people and respiratory droplets. Another common way of transmission is touching mouth, nose and eyes after touching surfaces contaminated with droplets shed by infected people. According to the results of the studies, the virus has a durability between 2-72 hours on different surfaces and items..Copyright © 2022, Universidade de Sao Paulo. Museu de Zoologia. All rights reserved.

Noncontact liquid–solid nanogenerators as self-powered droplet sensors

Liquid–solid triboelectric nanogenerators (L–S TENGs) can generate corresponding electrical signal responses through the contact separation of droplets and dielectrics and have a wide range of applications in energy harvesting and self-powered sensing. However, the contact between the droplet and the electret will cause the contact L–S TENG's performance degradation or even failure. Here we report a noncontact triboelectric nanogenerator (NCLS-TENG) that can effectively sense droplet stimuli without contact with droplets and convert them into electrical energy or corresponding electrical signals. Since there is no contact between the droplet and the dielectric, it can continuously and stably generate a signal output. To verify the feasibility of NCLS-TENG, we demonstrate the modified murphy's dropper as a smart infusion monitoring system. The smart infusion monitoring system can effectively identify information such as the type, concentration, and frequency of droplets. NCLS-TENG show great potential in smart medical, smart wearable and other fields.

Jahrestagung der Gesellschaft fur Padiatrische Pneumologie.

The proceedings contain 54 papers. The topics discussed include: cytokines in severe childhood asthma;transcriptional gene regulation of interleukin-6 in epithelial cells in viral-induced asthma exacerbation;assessment of the long-term safety and efficacy of dupilumab in children with asthma: LIBERTY ASTHMA EXCURSION;impulse oscillometry bronchodilator response in preschool children;pulmonary function in non-hospitalized adults and children after mild Covid-19;exhaled aerosols in PCR-confirmed SARS-CoV-2-infected children;early respiratory infectious diseases have an influence on the gut microbiome;comparison of three eradication treatment protocols for pseudomonas aeruginosa in children and adolescents with cystic fibrosis;neutrophilic airway inflammation in children with repaired esophageal atresia-tracheoesophageal fistula (EA/TEF);and multiplex immunofluorescence and multispectral imaging as a tool to evaluate host directed therapy.

From Microscopic Droplets to Macroscopic Crowds: Crossing the Scales in Models of Short-Range Respiratory Disease Transmission, with Application to COVID-19.

Short-range exposure to airborne virus-laden respiratory droplets is an effective transmission route of respiratory diseases, as exemplified by Coronavirus Disease 2019 (COVID-19). In order to assess the risks associated with this pathway in daily-life settings involving tens to hundreds of individuals, the chasm needs to be bridged between fluid dynamical simulations and population-scale epidemiological models. This is achieved by simulating droplet trajectories at the microscale in numerous ambient flows, coarse-graining their results into spatio-temporal maps of viral concentration around the emitter, and coupling these maps to field-data about pedestrian crowds in different scenarios (streets, train stations, markets, queues, and street cafés). At the individual scale, the results highlight the paramount importance of the velocity of the ambient air flow relative to the emitter's motion. This aerodynamic effect, which disperses infectious aerosols, prevails over all other environmental variables. At the crowd's scale, the method yields a ranking of the scenarios by the risks of new infections, dominated by the street cafés and then the outdoor market. While the effect of light winds on the qualitative ranking is fairly marginal, even the most modest air flows dramatically lower the quantitative rates of new infections.

A computational fluid dynamics—Population balance equation approach for evaporating cough droplets transport

Airborne diseases, including COVID-19, are transmitted by respiratory droplets, which makes the study of the evolution of these droplets important to control the transmission. However, the evolution of the droplets is complex, being a multiphase, polydisperse, multicomponent system undergoing evaporation. To numerically investigate such multiphase flows, there are mainly two approaches. One is the Eulerian–Lagrangian (E–L) approach, which is widely used due to its ability to trace the dispersion and evaporation of individual droplets. However, this approach generally has high costs and difficulty in post-processing. The other one is the Eulerian–Eulerian (E–E) approach, which, though having lower costs, is less adopted because of its failure to treat the features of polydispersity and evaporation. In order to take advantage of the low-costs of E–E approach, the population balance equation (PBE) is combined with the E–E approach to trace the polydisperse evaporating droplets. Two PBE solving methods, sectional method (SM) and quadrature based moment method (QBMM), are used and compared. The codes are developed based on the OpenFOAM library and their abilities to predict size changes of evaporating droplets, evolution of expelled airflow front, and aerosols concentration are assessed by using the experimental and numerical results in literature. Good agreements with the reported results are found, indicating the reliability of the CFD-PBE approaches. The SM and QBMM are finally applied in the transport of cough droplets in a 3D chamber. The suspending trends of small droplets and the falling trends of the large droplets are obtained by both methods. The droplets are found to be able to travel a distance longer than 2 m, which is valuable for the guidelines of social distancing. Additionally, the advantages and disadvantages of SM and QBMM are discussed.

Spectacular voyage of droplets: Gas turbines to SARS-CoV-2

I will provide an account of the interesting dynamics exhibited by droplets at multiple length and time scales in completely different domains, namely gas turbines and COVID-19. In the first part of my talk, I will discuss how the spread of COVID can happen through respiratory droplets and fomites. In this part, I will provide a detailed exposition of how respiratory droplet dynamics can be combined with a pandemic model to provide a first principle insights into infection spread rates. We will show through experiments using surrogate fluids how such models can be experimentally verified rigorously. Subsequently, I will show how fomites form and how the virions are embedded in the crystal network using both contact free as well as sessile droplets. In the second part of my talk, I will provide some insights into the dynamics of spray-swirl interaction with a particular focus on droplet transport, breakup and dispersion. I will show how the fundamental insights gained through such interactions can be used to design a new class of atomizers in gas turbines.

Numerical simulation of social distancing of preventing airborne transmission in open space with lateral wind direction, taking into account temperature of human body and floor surface.

This paper presents the numerical results of particle propagation in open space, taking into account the temperature of the human body and the surface of the ground. And also, the settling of particles or droplets under the action of gravitational force and transport in the open air is taken into account, taking into account the temperature during the process of breathing and sneezing or coughing. The temperature of the body and the surface of the ground, different rates of particle emission from the mouth, such as breathing and coughing or sneezing, are numerically investigated. The effect of temperature, cross-inlet wind, and the velocity of particle ejection from a person's mouth on social distancing is being investigated using a numerical calculation. The variable temperature of the human body forms a thermal plume, which affects the increase in the trajectory of the particle propagation, taking into account the lateral air flow. The thermal plume affects the particles in the breathing zone and spreads the particles over long distances in the direction of the airflow. The result of this work shows that in open space, taking into account the temperature of the body and the surface of the ground, a 2-m social distance may be insufficient for the process of sneezing and social distance must be observed depending on the breathing mode.

Risk assessment of airborne virus transmission in an intensive care unit due to single and sequential coughing.

The virus causing COVID-19 has constantly been mutating into new variants. Some of them are more transmissive and resistant to antibiotics. The current research article aims to examine the airborne transmission of the virus expelled by coughing action in a typical intensive care unit. Both single and sequential coughing actions have been considered to get closer to practical scenarios. The objective is to assess the effectiveness of air change per hour (ACH) on the risk of infection to a healthcare person and how the air change rate influences the dispersion of droplets. Such a study is seldom reported and has significant relevance. A total of four cases were analyzed, of which two were of sequential cough. When the ACH is changed from 6 to 12, the average particle residence time is reduced by ∼7 s. It is found that the risk of infection in the case of sequential cough will be relatively low compared to a single cough if the outlet of the indoor environment is placed above the patient's head. This arrangement also eliminates the requirement of higher ACH, which has significance from an energy conservation perspective.