The impact of COVID-19 pandemic on air pollution: a global research framework, challenges, and future perspectives

The published trend of studies on COVID-19 and diabetes: bibliometric analysis

Background

Since the COVID-19 pandemic outbreak, diabetes mellitus (DM) has been at the core of the confirmed risk factors for fatal or critical care unit-treated COVID-19 and COVID-19 related complications. Although relevant studies on DM have developed rapidly during the COVID-19 pandemic. However, the aforementioned research results have not been systematically quantified by means of bibliometric analysis.

Purpose

The purpose of this study is to provide a comprehensive analysis of the current status and trends of publications related to DM research during the COVID19 epidemic.

Methods

A bibliometric analysis was performed using the Web of Science database. In this study, we used citespace, R software and R-Bibliometrix to analyze keywords, most-cited authors, most-cited countries, most-cited global documents, and co-occurrence and co-citation networks.

Results

A total of 1688 publications was included in this study. Investigators from the United States contributed the most publications. The United States, China and Europe have the most collaboration with the other countries/regions. A total of 3355 institutions made contributions to this study. Of the top 10 institutions with the most publications, N8 Research Partnership showed the most centrality. Among the top 10 journals, Diabetes Research and Clinical Practice published the most articles. Among authors included, Khunti Kamlesh is rated first with 27 papers and has the highest centrality. The most frequently co-cited article is entitled "Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: a retrospective cohort study". The most popular keywords included diabetes, mortality, diabetes, outcome, occurrences, risk, and type 1 diabetes.

Conclusion

This bibliometric study provides an overall picture of DM research and research trends during the COVID-19 pandemic and provides a basis for researchers to develop their next research strategies.

The top 100 most cited articles on COVID-19 vaccine: a bibliometric analysis

This study aimed to uncover the current major topics regarding COVID-19 vaccine, and systematically evaluate the development trends for future research. The top 100 most cited original articles on COVID-19 vaccine from January 2020 to October 2022 were identified from Web of Science Core Collection database. CiteSpace (v6.1.R3) was adopted for bibliometric analysis with statistical and visual analysis. The number of citations ranged from 206 to 5881, with a median of 349.5. The USA (n = 56), England (n = 33), and China (n = 16) ranked the top three countries/regions in terms of the number of publications. Harvard Medical School (centrality = 0.71), Boston Children's Hospital (centrality = 0.67), and Public Health England (centrality = 0.57) were the top three institutions leading the way on COVID-19 vaccine research. The New England of medicine journal dominated with 22 articles in the 32 high-quality journals. The three most frequent keywords were immunization (centrality = 0.25), influenza vaccination (centrality = 0.21), and coronavirus (centrality = 0.18). Cluster analysis of keywords showed that the top four categories were protection efficacy, vaccine hesitancy, spike protein, and second vaccine dose (Q value = 0.535, S value = 0.879). Cluster analysis of cited references showed that top eight largest categories were Cov-2 variant, clinical trial, large integrated health system, COV-2 rhesus macaque, mRNA vaccine, vaccination intent, phase II study, and Cov-2 omicron variant (Q value = 0.672, S value = 0.794). The research on COVID-19 vaccine is currently the hottest topic in academic community. At present, COVID-19 vaccines researches have focused on vaccine efficacy, vaccine hesitancy, and the efficacy of current vaccines on omicron variants. However, how to increase vaccine uptake, focus on mutations in the spike protein, evaluate of the efficacy of booster vaccine, and how effective new vaccines under pre- and clinical development against omicron will be spotlight in the future.

Global trends and future prospects of COVID-19 and physical activity: Bibliometric analysis

BACKGROUND

Containment measures implemented during the COVID-19 pandemic have led to drastic changes in daily life and effects on health behaviors such as decrease in physical activity (PA) levels. This study aims to present a general framework to researchers on COVID-19 and PA research in relation with changes in studies within years, current trend topics, gaps in the research field and possible future trends.

METHODS

A total of 1819 articles indexed in the WoS core collection database were analyzed according to publication year, citation, country and institution collaborations, coword, co-citation networks, concept-topic trends and topic clusters using bibliometric analysis.

RESULTS

The most productive country was the USA(n = 335), and the most productive institution was University of London in UK (n = 38). The most cited publication was the study by Ammar et al, (2020) (n = 188). In 2020, the most popular topics were PA and health meanwhile in 2021 behavior, lifestyle, social media and in 2022 habits, long COVID, sleep quality topics were in the foreground. Studies in 2023 focus on how COVID-19 affects PA habits and the associations between COVID-19-based anxiety and sleep patterns. These studies focused especially on effects of sport participation on life quality, diet, depression, mental health on young athletes, children, adolescent persons, older adult groups.

CONCLUSIONS

An important gap in the study area is research on effect of changing lifestyle due to pandemic on individuals and the society during the Post COVID-19 period. If benefits of PA will not be limited to only physical benefits and psychological emotional, cognitive and social benefits are also taken into consideration, it is important that researchers conduct long-term and widescale observations.

A bibliometric analysis of the impact of COVID-19 social lockdowns on air quality: research trends and future directions

Social lockdowns improved air quality during the COVID-19 pandemic. Governments had previously spent a lot of money addressing air pollution without success. This bibliometric study measured the influence of COVID-19 social lockdowns on air pollution, identified emerging issues, and discussed future perspectives. The researchers examined the contributions of countries, authors, and most productive journals to COVID-19 and air pollution research from January 1, 2020, to September 12, 2022, from the Web of Sciences Core Collection (WoS). The results showed that (a) publications on the COVID-19 pandemic and air pollution were 504 (research articles) with 7495 citations, (b) China ranked first in the number of publications (n = 151; 29.96% of the global output) and was the main country in international cooperation network, followed by India (n = 101; 20.04% of the total articles) and the USA (n = 41; 8.13% of the global output). Air pollution plagues China, India, and the USA, calling for many studies. After a high spike in 2020, research published in 2021 declined in 2022. The author's keywords have focused on "COVID-19," "air pollution," "lockdown," and "PM₂₅." These keywords suggest that research in this area is focused on understanding the health impacts of air pollution, developing policies to address air pollution, and improving air quality monitoring. The COVID-19 social lockdown served as a specified procedure to reduce air pollution in these countries. However, this paper provides practical recommendations for future research and a model for environmental and health scientists to examine the likely impact of COVID-19 social lockdowns on urban air pollution.

Distribution, sources and health risks of heavy metals in indoor dust across China

The potential effects of heavy metals on human health have attracted increasing attention as most people spend up to 90% of their time indoors. Human exposure to heavy metals in indoor dust have only been characterised for limited regions in China, and full-scale data for different functional areas are not available. Therefore, this review analysed the concentrations, contamination characteristics, and potential health risks of seven heavy metals (including zinc (Zn), lead (Pb), copper (Cu), chromium (Cr), nickel (Ni), arsenic (As), and cadmium (Cd)) in indoor dust at 3392 sampling sites in 55 cities across 27 provincial regions of China based on literature data. Results revealed that the median heavy metal concentrations in indoor dust throughout China decreased in the following order: Zn > Pb > Cu > Cr > Ni > As > Cd. Traffic emissions and decorative materials are the primary sources of heavy metal pollution in indoor dust. No considerable non-carcinogenic risk was found for Zn, Cu, Cr, Ni, and Cd in indoor dust, while Pb and As exhibited potential non-carcinogenic risks to children, primarily distributed in cities across Southern China. Meanwhile, the carcinogenic risks posed by Cr and Ni were higher than those posed by As and Cd, especially in Southern China. Therefore, effective measures in Southern China should prioritised for controlling Pb, Cr, Ni and As pollution in indoor dust to reduce human health risk. This review is useful for policy decision-making and protecting human from exposure to heavy metals in indoor dust across China.

Hotspots and Frontiers of Host Immune Response in Idiopathic Pulmonary Fibrosis: A Bibliometric and Scientific Visual Research from 2000 to 2022

Background

Idiopathic pulmonary fibrosis (IPF) is a disease with significant morbidity, progressive deterioration of lung function till death, and lack of effective treatment options. This study aims to explore the global research trends in IPF and immune response to predict the research hotspot in the future. Materials and methods. All related publications on IPF and immune response since the establishment of diagnostic criteria for IPF were retrieved using the Web of Science (WOS) database. VOSviewer, GraphPad Prism 6, CiteSpace version 5.6. R5 64-bit, and a bibliometrics online platform were used to extract and analyze the trends in relevant fields.

Results

From March 1, 2000, to September 30, 2022, a total of 658 articles with 25,126 citations met the inclusion criteria. The United States ranked first in number of publications (n = 217), number of citations (n = 14,745), and H-index (62). China ranked second in publications (n = 124) and seventh and fifth for citation frequency and H-index, respectively. The American Journal of Respiratory and Critical Care Medicine (impact factor = 30.528) published the most articles in the field. The author Kaminski N. from the United States was the most influential author with 26 publications and an H-index of 24. Among the 52 keywords that co-occurred at least 20 times, the main keywords were concentrated in "Inflammation related" and "Biomarker related" clusters. "biomarker" (AAY 2018.64, 25 times) was a newly emerged keyword.

Conclusions

The United States has an unequivocal advantage in IPF and immunization, but China shows a faster developing trend. The American Journal of Respiratory and Critical Care Medicine should be prioritized for leading articles. This study indicates that exploration of ideal immune-related biomarkers to provide evidence for the clinical work of IPF might be a hotspot in the near future.

The published trend of studies on COVID-19 and dietary supplements: Bibliometric analysis

BACKGROUND

There are no guidelines on dietary supplements for the prevention or treatment of COVID-19. Therefore, we would like to analyze and discuss the above confusion through the bibliometric analysis.

METHODS

On 3 September 2022, we conducted a search of all relevant literature retrieved from the WOS core collection database from 2019 to 2022. CiteSpace software is used to build the visual co-occurrence network.

RESULTS

In the study of "COVID-19 and Dietary Supplements", the total of 170 authors published 855 articles in 451 journals. Several distinct core author groups were formed by Wang, Grant, Singh, Zhu, and other authors with numerous publications. The majority of the publications came from the Shahid Beheshti University of Medical Sciences. The United States of America had the highest number of publications. By analyzing keyword clusters, we found that the research focus was dietary supplements (vitamin D, vitamin K, vitamin C), mechanisms (ferritin, specialized pro-resolving mediators (SPMs), oxidative stress), research methods (clinical trials), and the prevention and treatment strategies (lockdown) of COVID-19.

CONCLUSIONS

vitamin D is the mainstream dietary supplement for COVID-19. There are still numerous controversies that deserve further discussion. Such as whether the use of vitamin D or TCM offers benefits, and whether the addition of dietary supplements during the lockdown measures can help prevent COVID-19 infection.

Analyzing the spatio-temporal directions of air pollutants for the initial wave of Covid-19 epidemic over Bangladesh: Application of satellite imageries and Google Earth Engine

One of the most critical issues for city viability and global health is air quality. The shutdown interval for the COVID-19 outbreaks has turned into an ecological experiment, allowing researchers to explore the influence of human/industrial operations on air quality. In this study, we have observed and examined the spatial pattern of air pollutants, specifically CO, NO₂, SO₂, O3 as well as AOD Over Bangladesh. For that reason, the timeline was chosen from March 2019 to October 2020 (before and during the first surge of COVID-19). The full analysis has been performed in Google Earth Engine (GEE). The findings showed that, CO, SO₂, and AOD levels dropped significantly, but SO₂ dropped slowly and O₃ levels were similar, with marginally greater quantities in some areas during the lockdown than in 2019. During the shutdown, the association involving airborne pollutants and weather parameters (temperature and rainfall) revealed that rainfall and temperature were directly associated with air pollutants. COVID-19 mortality had a high positive connection with NO₂ (R² = 0.145; r = 0.38) and AOD (R² = 0.17; r = 0.412). It is also found that various air impurities concentration has a strong relationship with Covid death. It would help the policymakers and officials to gain a better understanding of the sources of atmospheric emissions to develop a substantial proof of short- and long-term mitigation ways to enhance air quality and reduce the associated disease and disability burden.

Publication trends of research on COVID-19 and host immune response: A bibliometric analysis

Introduction

As the first bibliometric analysis of COVID-19 and immune responses, this study will provide a comprehensive overview of the latest research advances. We attempt to summarize the scientific productivity and cooperation across countries and institutions using the bibliometric methodology. Meanwhile, using clustering analysis of keywords, we revealed the evolution of research hotspots and predicted future research focuses, thereby providing valuable information for the follow-up studies.

Methods

We selected publications on COVID-19 and immune response using our pre-designed search strategy. Web of Science was applied to screen the eligible publications for subsequent bibliometric analyses. GraphPad Prism 8.0, VOSviewer, and CiteSpace were applied to analyze the research trends and compared the contributions of countries, authors, institutions, and journals to the global publications in this field.

Results

We identified 2,200 publications on COVID-19 and immune response published between December 1, 2019, and April 25, 2022, with a total of 3,154 citations. The United States (611), China (353), and Germany (209) ranked the top three in terms of the number of publications, accounting for 53.3% of the total articles. Among the top 15 institutions publishing articles in this area, four were from France, four were from the United States, and three were from China. The journal Frontiers in Immunology published the most articles (178) related to COVID-19 and immune response. Alessandro Sette (31 publications) from the United States were the most productive and influential scholar in this field, whose publications with the most citation frequency (3,633). Furthermore, the development and evaluation of vaccines might become a hotspot in relevant scope.

Conclusions

The United States makes the most indispensable contribution in this field in terms of publication numbers, total citations, and H-index. Although publications from China also take the lead regarding quality and quantity, their international cooperation and preclinical research need to be further strengthened. Regarding the citation frequency and the total number of published articles, the latest research progress might be tracked in the top-ranking journals in this field. By analyzing the chronological order of the appearance of retrieved keywords, we speculated that vaccine-related research might be the novel focus in this field.