Identifying the extent of environmental contamination of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is essential for infection control and prevention. The extent of environmental ...contamination has not been fully investigated in the context of severe coronavirus disease (COVID-19) patients.
To investigate environmental SARS-CoV-2 contamination in the isolation rooms of severe COVID-19 patients requiring mechanical ventilation or high-flow oxygen therapy.
Environmental swab samples and air samples were collected from the isolation rooms of three COVID-19 patients with severe pneumonia. Patients 1 and 2 received mechanical ventilation with a closed suction system, while patient 3 received high-flow oxygen therapy and non-invasive ventilation. Real-time reverse transcription–polymerase chain reaction (rRT–PCR) was used to detect SARS-CoV-2; viral cultures were performed for samples not negative on rRT–PCR.
Of the 48 swab samples collected in the rooms of patients 1 and 2, only samples from the outside surfaces of the endotracheal tubes tested positive for SARS-CoV-2 by rRT–PCR. However, in patient 3's room, 13 of the 28 environmental samples (fomites, fixed structures, and ventilation exit on the ceiling) showed positive results. Air samples were negative for SARS-CoV-2. Viable viruses were identified on the surface of the endotracheal tube of patient 1 and seven sites in patient 3's room.
Environmental contamination of SARS-CoV-2 may be a route of viral transmission. However, it might be minimized when patients receive mechanical ventilation with a closed suction system. These findings can provide evidence for guidelines for the safe use of personal protective equipment.
The Higgs mechanism, i.e., spontaneous symmetry breaking of the quantum vacuum, is a cross-disciplinary principle, universal for understanding dark energy, antimatter and quantum materials, from ...superconductivity to magnetism. Unlike one-band superconductors (SCs), a conceptually distinct Higgs amplitude mode can arise in multi-band, unconventional superconductors via strong interband Coulomb interaction, but is yet to be accessed. Here we discover such hybrid Higgs mode and demonstrate its quantum control by light in iron-based high-temperature SCs. Using terahertz (THz) two-pulse coherent spectroscopy, we observe a tunable amplitude mode coherent oscillation of the complex order parameter from coupled lower and upper bands. The nonlinear dependence of the hybrid Higgs mode on the THz driving fields is distinct from any known SC results: we observe a large reversible modulation of resonance strength, yet with a persisting mode frequency. Together with quantum kinetic modeling of a hybrid Higgs mechanism, distinct from charge-density fluctuations and without invoking phonons or disorder, our result provides compelling evidence for a light-controlled coupling between the electron and hole amplitude modes assisted by strong interband quantum entanglement. Such light-control of Higgs hybridization can be extended to probe many-body entanglement and hidden symmetries in other complex systems.
Peanut (PN) and tree nuts (TNs) are common causes of anaphylaxis in Western countries, but no information is available in Korea. To feature clinical characteristics of anaphylaxis caused by PN, TNs, ...and seeds, a retrospective medical record review was performed in 14 university hospitals in Korea (2009–2013). One hundred and twenty‐six cases were identified, with the mean age of 4.9 years. PN, walnut (WN), and pine nut accounted for 32.5%, 41.3%, and 7.1%, respectively. The median values of specific IgE (sIgE) to PN, WN, and pine nut were 10.50, 8.74, and 4.61 kUA/l, respectively. Among 50 cases managed in the emergency department, 52.0% were treated with epinephrine, 66.0% with steroid, 94.0% with antihistamines, 36.0% with oxygen, and 48.0% with bronchodilator. In conclusion, WN, PN, and pine nut were the three most common triggers of anaphylaxis in Korean children, and anaphylaxis could occur at remarkably low levels of sIgE.
Giant Piezoelectricity on Si for Hyperactive MEMS Baek, S. H.; Park, J.; Kim, D. M. ...
Science (American Association for the Advancement of Science),
11/2011, Letnik:
334, Številka:
6058
Journal Article
Recenzirano
Microelectromechanical systems (MEMS) incorporating active piezoelectric layers offer integrated actuation, sensing, and transduction. The broad implementation of such active MEMS has long been ...constrained by the inability to integrate materials with giant piezoelectric response, such as Pb(MG 1/3 Nb 2/3 )O₃-PbTiO₃ (PMN-PT). We synthesized high-quality PMN-PT epitaxial thin films on vicinal (001) Si wafers with the use of an epitaxial (001) SrTiO₃ template layer with superior piezoelectric coefficients (e 31,f = -27 ± 3 coulombs per square meter) and figures of merit for piezoelectric energy-harvesting systems. We have incorporated these heterostructures into microcantilevers that are actuated with extremely low drive voltage due to thin-film piezoelectric properties that rival bulk PMN-PT single crystals. These epitaxial heterostructures exhibit very large electromechanical coupling for ultrasound medical imaging, microfluidic control, mechanical sensing, and energy harvesting.
Summary
Background
Recent studies suggest that Staphylococcus aureus enterotoxin sensitization is a risk factor for asthma. However, there is a paucity of epidemiologic evidence on adult‐onset asthma ...in community‐based populations.
Objective
We sought to evaluate the epidemiology and the clinical significance of staphylococcal enterotoxin sensitization in community‐based adult populations.
Methods
The present analyses were performed using the baseline data set of Korean adult population surveys, consisting of 1080 adults (mean age = 60.2 years) recruited from an urban and a rural community. Questionnaires, methacholine challenge tests, and allergen skin tests were performed for defining clinical phenotypes. Sera were analysed for total IgE and enterotoxin‐specific IgE using ImmunoCAP.
Results
Staphylococcal enterotoxin sensitization (≥ 0.35 kU/L) had a prevalence of 27.0%. Risk factors were identified as male sex, current smoking, advanced age (≥ 61 years), and inhalant allergen sensitization. Current asthma was mostly adult onset (≥ 18 years old) and showed independent associations with high enterotoxin‐specific IgE levels in multivariate logistic regression tests. In multivariate linear regressions, staphylococcal enterotoxin‐specific IgE level was identified as the major determinant factor for total IgE level.
Conclusions and Clinical Relevance
Staphylococcal enterotoxin sensitization was independently associated with adult‐onset asthma in adult community populations. Strong correlations between the enterotoxin‐specific IgE and total IgE levels support the clinical significance. The present findings warrant further studies for the precise roles of staphylococcal enterotoxin sensitization in the asthma pathogenesis.
We report the identification of metastable isomeric states of
228
Ac at 6.28 keV, 6.67 keV and 20.19 keV, with lifetimes of an order of 100 ns. These states are produced by the
β
-decay of
228
Ra, a ...component of the
232
Th decay chain, with
β
Q-values of 39.52 keV, 39.13 keV and 25.61 keV, respectively. Due to the low Q-value of
228
Ra as well as the relative abundance of
232
Th and their progeny in low background experiments, these observations potentially impact the low-energy background modeling of dark matter search experiments.
Summary
Background
Skin colonization or infection with Staphylococcus aureus is known to trigger aggravation of atopic dermatitis (AD). However, the exact mechanisms by which S. aureus can worsen AD ...are unknown.
Objective
We investigated whether and how S. aureus‐derived membrane vesicles (MVs) contribute to worsening of AD.
Methods
Immunohistochemical and immunoelectron microscopic analyses were performed to detect staphylococcal protein A (SPA) in the epidermis of AD lesions. HaCaT cells were treated with S. aureus MVs and were analysed for the expression of cytokine genes. Immunopathology and cytokine gene profiles were analysed after topical application of S. aureus MVs to AD‐like skin lesions in a mouse model.
Results
The MV component SPA was detected in the keratinocytes as well as in the intercellular space of the epidermis of AD lesions colonized with S. aureus. Intact MVs from S. aureus delivered their components to keratinocytes and stimulated pro‐inflammatory cytokine gene expression in vitro. A knock‐down of Toll‐like receptor 2 or nucleotide‐binding oligomerization domain 2 using small interfering RNAs suppressed interleukin‐8 gene expression. Topical application of intact S. aureus MVs to AD‐like skin lesions in the mouse model induced massive infiltration of inflammatory cells and the resulting eczematous dermatitis. This inflammatory reaction was associated with a mixed Th1/Th2 immune response and enhanced expression of chemokine genes in AD‐like skin lesions.
Conclusions and Clinical Relevance
This study showed the importance of S. aureus MVs as a potent mediator for worsening of AD among many exogenous worsening factors of AD. Thus, S. aureus MVs may be regarded as one of the therapeutic targets for the management of AD aggravation.
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