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1.
2021 2nd International Conference on Applied Physics and Computing, ICAPC 2021 ; 2083, 2021.
Article in English | Scopus | ID: covidwho-1595984

ABSTRACT

Most of the diseases caused by virus mainly spread through droplets in the air. The pathogen bearing droplets go deep into people's lungs and cause infection. In this paper, we analyze the safe distance, the minimum range to keep droplets containing virus particles from entering lungs, and thereby carrying the virus inside the lung. Einstein equation for diffusivity of a particle and the wide of the Gaussian distribution of the particles in Brownian movement are used in the calculation of the range a viruscontaining mucosal vary droplet can reach. Moreover, we used datas recorded in a previous paper named "Visualization of sneeze ejecta: steps of fluid fragmentation leading to respiratory droplets" by B. E. Scharfman et. all to generate our results. © 2021 Institute of Physics Publishing. All rights reserved.

2.
Physical Review X ; 11(3):9, 2021.
Article in English | Web of Science | ID: covidwho-1398211

ABSTRACT

The combination of nontrivial band topology and symmetry-breaking phases gives rise to novel quantum states and phenomena such as topological superconductivity, quantum anomalous Hall effect, and axion electrodynamics. Evidence of intertwined charge density wave (CDW) and superconducting order parameters has recently been observed in a novel kagome material AV(3)Sb(5) (A = K, Rb, Cs) that features a Z(2) topological invariant in the electronic structure. However, the origin of the CDW and its intricate interplay with the topological state has yet to be determined. Here, using hard-x-ray scattering, we demonstrate a three-dimensional CDW with 2 x 2 x 2 superstructure in (Rb, Cs)V3Sb5. Unexpectedly, we find that the CDW fails to induce acoustic phonon anomalies at the CDW wave vector but yields a novel Raman mode that quickly damps into a broad continuum below the CDW transition temperature. Our observations exclude strong electron-phonon-coupling-driven CDW in AV(3)Sb(5) and support an unconventional CDW that was proposed in the kagome lattice at van Hove filling.

3.
6th International Conference on Information Management and Technology, CIMTECH 2021 ; 2021.
Article in English | Scopus | ID: covidwho-1394241

ABSTRACT

Information technology is an important force to promote economic and social change. Information technology is not only used in human production and life, but also gradually infiltrated into higher education and teaching. Under novel coronavirus pneumonia, the path of university curriculum resources construction is discussed in this paper. The construction of a more rational and abundant information curriculum resource is achieved through the classification and integration of university education curriculum resources, which fully meets the needs of College Teaching in the special period. © 2021 ACM.

4.
Green Chemistry ; : 7, 2021.
Article in English | Web of Science | ID: covidwho-1356588

ABSTRACT

Quaternary ammonium compounds (QACs) are a class of cationic surfactants routinely used for the disinfection of industries, institutions and households, and have seen a sharp increase in use during the COVID-19 pandemic. However, current commercial QACs consist of only stable chemical bonds such as C-N, C-C, and C-H, which makes their natural degradation rather difficult. Recent studies suggest that emerging negative environmental impacts, such as systemic antibiotics resistance and toxicity to living organisms, are directly associated with prolonged exposure to QACs. Here we report a new class of QAC which contains relatively volatile chemical functional groups such as ester and thioether bonds. Degradation kinetics in aqueous solutions suggests that the stability of these QACs depends not only on their intrinsic hydrophobicity but also on external environmental factors such as pH, temperature and ion presence. The microbicidal effects of QACs containing carbon chains with various lengths were also tested, one of which, named "Ephemora", is highly active against a broad spectrum of microbes including fungi, bacteria and viruses, for instance, methicillin-resistant Staphylococcus aureus (MRSA). The easy synthesis and purification of Ephemora starting from inexpensive commercially available reagents, together with its excellent antimicrobial activity and ability to degrade in natural waters over time, make its large-scale commercial production possible.

5.
Eur Rev Med Pharmacol Sci ; 24(24): 13065-13071, 2020 12.
Article in English | MEDLINE | ID: covidwho-1000853

ABSTRACT

OBJECTIVE: Whether patients with COVID-19 require invasive mechanical ventilation (MV) is not yet clear. This article summarizes the clinical treatment process and clinical data of patients with COVID-19 and analyzes the predictive factors for mechanical ventilation for these patients. MATERIALS AND METHODS: A retrospective study was carried out from January 5, 2020, to March 23, 2020, including 98 patients with COVID-19 treated at three designated hospitals in Huangshi City, Hubei Province. Data collection included demographics, previous underlying diseases, clinical manifestations, laboratory examinations, imaging examination results, diagnosis, and prognosis. This study presents a summary of the patients' overall clinical characteristics and clarifies the predictive factors for MV in patients with COVID-19. RESULTS: There were 56 males and 42 females included in this study. The mortality rate was 26.53% (26/98). Fever, cough, and chest tightness were the most common symptoms (64.3%, 37.8%, and 12.2%, respectively). Thirty cases required MV, 30.61% of the total cases, and the mortality rate was 73.33%. The univariate comparison showed that dyspnea, acute physiologic assessment, chronic health evaluation (APACHE II) score, and the ratio between arterial blood oxygen partial pressure (PaO2) and oxygen concentration (FiO2) (P/F) were statistically different between the MV group and the non-MV group (p < 0.05). CONCLUSIONS: Results showed the following: dyspnea; increased white blood cell count; decreased platelets; lowered albumin levels; increased urea nitrogen; increased levels of myocardial enzymes Creatine Kinase (CK), Creatine Kinase, MB Form (CKMB) and lactate dehydrogenase (LDH); increased lactate, and lowered blood calcium tests. These findings may indicate that the patients have an increased probability of needing MV support. A cutoff value for the initial APACHE II score of >11.5 and the initial PaO2/FiO2 ratio of <122.17 mmHg should be considered for MV support for patients with COVID-19.


Subject(s)
COVID-19/therapy , Oxygen/blood , Partial Pressure , Respiration, Artificial/statistics & numerical data , APACHE , Aged , Aged, 80 and over , Area Under Curve , Blood Urea Nitrogen , COVID-19/blood , COVID-19/mortality , COVID-19/physiopathology , Creatine Kinase/blood , Creatine Kinase, MB Form/blood , Dyspnea/physiopathology , Female , Humans , Hypoalbuminemia/blood , Hypocalcemia/blood , L-Lactate Dehydrogenase/blood , Lactic Acid/blood , Leukocytosis/blood , Male , Middle Aged , ROC Curve , Retrospective Studies , Risk Assessment , SARS-CoV-2 , Thrombocytopenia/blood
6.
Frontiers in Applied Mathematics and Statistics ; 6, 2020.
Article in English | Scopus | ID: covidwho-828698

ABSTRACT

The sudden onset of the coronavirus (SARS-CoV-2) pandemic has resulted in tremendous loss of human life and economy in more than 210 countries and territories around the world. While self-protections such as wearing masks, sheltering in place, and quarantine policies and strategies are necessary for containing virus transmission, tens of millions of people in the U.S. have lost their jobs due to the shutdown of businesses. Therefore, how to reopen the economy safely while the virus is still circulating in population has become a problem of significant concern and importance to elected leaders and business executives. In this study, mathematical modeling is employed to quantify the profit generation and the infection risk simultaneously from a business entity's perspective. Specifically, an ordinary differential equation model was developed to characterize disease transmission and infection risk. An algebraic equation is proposed to determine the net profit that a business entity can generate after reopening and take into account the costs associated of several protection/quarantine guidelines. All model parameters were calibrated based on various data and information sources. Sensitivity analyses and case studies were performed to illustrate the use of the model in practice. The results show that with a combination of necessary infection protection measures implemented, a business entity may stand a good opportunity to generate a positive net profit while successfully controlling the within-business infection prevalence under that in the general population. The use of personal protective equipment (PPE) is also found of significant importance, especially at the early stage of business reopening. © Copyright © 2020 Miao, Gao, Feng, Zhong, Zhu, Wu, Swartz, Luo, DeSantis, Lai, Bauer, Pérez, Rong and Lairson.

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