Morphological Analysis of a Collapsing Cavitation Bubble near a Solid Wall with Complex Geometry

Featured Application: Collapsing cavitation bubbles can be used in material surface cleaning, the medical field, and so on. By adjusting the micro-jet intensity of the collapsing bubbles, the cavitation phenomenon can be employed to clean irregular material surfaces, such as sections, cracks, and vegetable leaves. In the medical field, cavitation bubbles can be used as microbubble contrast agents for ultrasound diagnostic imaging or vehicles for drug or gene delivery. The growth and violent collapse of cavitation bubbles can also be employed in sterilization or killing viruses such as COVID-19. The interaction mechanism between the cavitation bubble and a solid wall is a basic problem in bubble collapse prevention and application. In particular, when bubble collapse occurs near solid walls with arbitrarily complex geometries, it is difficult to efficiently establish a model and quantitatively explore the interaction mechanism between bubbles and solid walls. Based on the advantages of the lattice Boltzmann method, a model for cavitation bubble collapse close to a solid wall was established using the pseudopotential multi-relaxation-time lattice Boltzmann model. Solid walls with arbitrarily complex geometries were introduced in the computational domain, and the fractal dimension was used to quantify the complexity of the solid wall. Furthermore, owing to the lack of periodicity, symmetry, spatial uniformity and obvious correlation in this process, the Minkowski functionals-based morphological analysis method was introduced to quantitatively describe the temporal evolution of collapsing bubble profiles and acquire effective information from the process. The interaction mechanism between the bubble and solid wall was investigated using evolutions of physical fields. In addition, the influences of the solid walls' surface conditions and the position parameter on collapsing bubbles were discussed. These achievements provide an efficient tool for quantifying the morphological changes of the collapsing bubble. © 2023 by the authors.

The optimal anticoagulation strategy for COVID-19, prophylactic or therapeutic?: a meta-analysis, trial sequential analysis, and meta-regression of more than 27,000 participants

Background: Anticoagulants are promising regimens for treating coronavirus disease 2019 (COVID-19). However, whether prophylactic or intermediate-to-therapeutic dosage is optimal remains under active discussion. Methods: We comprehensively searched PubMed, Embase, Scopus, Web of Science, Cochrane Library, ClinicalTrials, and MedRxiv databases on April 26, 2022. Two independent researchers conducted literature selection and data extraction separately according to predetermined criteria. Notably, this is the first meta-analysis on COVID-19, taking serious consideration regarding the dosage overlap between the 2 comparison groups of prophylactic anticoagulation (PA) and intermediate-to-therapeutic anticoagulation (I-TA). Results: We included 11 randomized controlled trials (RCTs) and 36 cohort studies with 27,051 COVID-19 patients. By analyzing all the RCTs, there was no significant difference in mortality between the PA and I-TA groups, which was further confirmed by trial sequential analysis (TSA) (odds ratio [OR]: 0.93;95% confidence interval [CI]: 0.71–1.22;P = 0.61;TSA adjusted CI: 0.71–1.26). The rate of major bleeding was remarkably higher in the I-TA group than in the PA group, despite adjusting for TSA (OR: 1.73;95% CI: 1.15–2.60;P = 0.009;TSA adjusted CI: 1.09–2.58). RCTs have supported the beneficial effect of I-TA in reducing thrombotic events. After including all studies, mortality in the I-TA group was significantly higher than in the PA group (OR: 1.38;95% CI: 1.15–1.66;P = 0.0005). The rate of major bleeding was similar to the analysis from RCTs (OR: 2.24;95% CI: 1.86–2.69;P < 0.00001). There was no distinct difference in the rate of thrombotic events between the 2 regimen groups. In addition, in both critical and noncritical subgroups, I-TA failed to reduce mortality but increased major bleeding rate compared with PA, as shown in meta-analysis of all studies, as well as RCTs only. Meta-regression of all studies suggested that there was no relationship between the treatment effect and the overall risk of mortality or major bleeding (P = 0.14, P = 0.09, respectively). Conclusion: I-TA is not superior to PA for treating COVID-19 because it fails to lower the mortality rate but increases the major bleeding rate in both critical and noncritical patients. Copyright © 2022 Shandong University, published by Wolters Kluwer, Inc.

Informetric analysis of researches on application of artificial intelligence in COVID-19 prevention and control

The COVID-19 (2019 novel Coronavirus) is the most widespread pandemic infectious disease encountered in human history. Its economic losses and the number of countries involved rank first in the history of human viruses. Since the outbreak of the COVID-19 pandemic around the world, AI has made a great contribution to the prevention and control of the COVID-19 pandemic. In this paper, researches on the application of artificial intelligence in COVID-19 pandemic prevention and control were analyzed by informetric method. 432 papers indexed in Thomson Reuters's Web of Science were studied by the perspectives of categories of researches, high frequency keywords, authors, institutions, journals and countries, and we get conclusions as follows: The analysis of keywords cooccurence shows application of machine learning and deep learning in COVID-19 pandemic diagnosis and prediction. The journal that received the most cites was (Radiology) and the journal that published the most papers was (Journal of Medical Internet Research). USA, India and China have the largest number of published articles. USA, China and UK are most influential countries. We also analyzed the review literature on the application of AI in COVID-19 pandemic prevention and control in the Web of Science, and found that these papers specifically can be divided into the following three categories: The first is the application of AI in clinical diagnosis and treatment, the second is the application of AI in the development of anti-epidemic drugs, and the third is the role of AI in the epidemiological research of COVID-19 and the social governance of pandemic prevention and control. © 2021 SPIE.

Systematic review of integrated traditional Chinese and western medicine in treatment of COVID-19

Objective: To systematically evaluate the efficacy of integrated traditional Chinese and western medicine in the treatment of COVID-19, and to provide evidence for the clinical treatment of COVID-19. Methods: PubMed, Medline, EMbase, CNKI, Wanfang and VIP databases were searched by computer to collect clinical studies on the treatment of COVID-19 combined with traditional Chinese and western medicine. The retrieval time was up to February 2021. According to the inclusion and exclusion criteria, two researchers independently retrieved and screened literatures and extracted data, and Meta-analysis was performed using Stata 12.0 software. Results: A total of 27 studies were included in the Meta-analysis, including 12 RCTs and 15 retrospective studies, involving 2215 patients. The results of Meta-analysis showed that integrated traditional Chinese and western medicine could significantly shorten the length of hospital stay for COVID-19 patients [WMD=-0.84, 95% CI (-1.42, -0.27), P=0.004];The effective rate [RR=1.14, 95% CI (1.08, 1.21), P=0.000], lung CT improvement rate [RR=1.19, 95% CI (1.04, 1.35), P=0.000], and nucleic acid negative conversion rate [RR=1.40, 95% CI (1.16, 1.69), P=0.000] was increased;Patients' clinical symptoms was improved [WMD=-0.82, 95% CI (-1.08, -0.55), P=0.000] and the rate of transforming to severe disease was reduced [RR=0.37, 95%CI (0.25, 0.56), P=0.000]. In addition, compared with western medicine treatment alone, the disappearance rate of fever, cough and fatigue in COVID-19 patients treated with integrated Chinese and western medicine was significantly increased and the duration was significantly shortened (P < 0.05). The results of subgroup analysis were consistent with the above results, with statistical differences ( P< 0.05). Conclusion: The treatment of COVID-19 with integrated Chinese and western medicine is better than that with western medicine alone, and can significantly improve the treatment efficiency, CT improvement rate and nucleic acid negative conversion rate, reduce the proportion of ordinary patients converted to critical patients and improve the main clinical symptoms of COVID-19 patients. Thus the treatment of integrated Chinese and western medicine has positive clinical value for COVID-19. © 2021, Editorial Office of Chinese Traditional and Herbal Drugs. All right reserved.

Social responses to epidemics depicted by cinema

Films illustrate 2 ways that epidemics can affect societies: Fear leading to a breakdown in sociability and fear stimulating preservation of tightly held social norms. The first response is often informed by concern over perceived moral failings within society, the second response by the application of arbitrary or excessive controls from outside the community. © 2020 Centers for Disease Control and Prevention (CDC). All rights reserved.

Individuals with Down syndrome hospitalized with COVID-19 have more severe disease.

PURPOSE: Rare genetic conditions like Down syndrome (DS) are historically understudied. Infection is a leading cause of mortality in DS, along with cardiac anomalies. Currently, it is unknown how the COVID-19 pandemic affects individuals with DS. Herein, we report an analysis of individuals with DS who were hospitalized with COVID-19 in New York, New York, USA. METHODS: In this retrospective, dual-center study of 7246 patients hospitalized with COVID-19, we analyzed all patients with DS admitted in the Mount Sinai Health System and Columbia University Irving Medical Center. We assessed hospitalization rates, clinical characteristics, and outcomes. RESULTS: We identified 12 patients with DS. Hospitalized individuals with DS are on average ten years younger than patients without DS. Patients with DS have more severe disease than controls, particularly an increased incidence of sepsis and mechanical ventilation. CONCLUSION: We demonstrate that individuals with DS who are hospitalized with COVID-19 are younger than their non-DS counterparts, and that they have more severe disease than age-matched controls. We conclude that particular care should be considered for both the prevention and treatment of COVID-19 in these patients.

COVID-19 Case and Contact Investigation in an Office Workspace.

This investigation report describes a case of COVID-19 in a combined military and civilian office workspace and the contact investigation and mitigation efforts that followed. This office space included an embedded public health officer who was able to conduct the contact investigation and advise on the outbreak response. Over a 3-day period, the index case unintentionally exposed 150 coworkers to SARS-CoV-2 through participation in carpools, conferences, and small meetings. Of these exposures 37 were considered medium risk at the time and 113 were considered low risk. A total of 5 contacts reported COVID-like-symptoms at the time of the investigation and another 5 developed symptoms during the 14-day quarantine period and all were directed to self-isolate. None of the contacts required hospitalization and all the symptomatic contacts tested negative for SARS-CoV-2. With the advice and aid of the embedded public health officer, the office authorized telework, conducted thorough cleaning of spaces, distributed informative messaging, conducted virtual question-and-answer forums, and evaluated outbreak policies. This report demonstrates that the close integration of public health and office management can lead to rapid identification of those at risk of infection and implementation of mitigation and control efforts to stop the spread of disease.