COVID-19 Resources

MDPI Comment on the COVID-19 Virus

Since 1996, MDPI has been committed to supporting the research community by providing the latest research freely available and making relevant and useful research available as quickly as possible. The world is current experiencing a pandemic of COVID-19, and researchers are working extremely hard to understand it and find a cure.

The values MDPI holds strongly are particularly important at the moment, and we will continue to publish relevant, peer-reviewed research as quickly as possible in open access format. This means that it will immediately be available for researchers, health professionals, and the general public to read, distribute, and reuse. We believe that scientific advancements will be crucial to overcoming this pandemic, and will do everything we can to support researchers working looking for solutions.

This page contains a variety of information related to COVID-19 available from MDPI, including journal articles, special issues, and preprints, among others.

Open AccessArticle

Impact of the COVID-19 Pandemic on the Diagnosis of Colorectal Cancer within a Population-Based Organized Screening Program

Joaquín Cubiella

Beatriz Calderón-Cruz

Raquel Almazán

and

Ángel Gómez-Amorín

Cancers 2023, 15(19), 4853; https://doi.org/10.3390/cancers15194853 (registering DOI) - 04 Oct 2023

Abstract

Background: The interruption of the activity of population-based organized colorectal cancer (CRC) screening programs due to the COVID pandemic may have affected their results in terms of the detection of preneoplastic lesions and CRC. We evaluated the impact of the COVID pandemic on the delays, participation, adherence to colonoscopies, lesions detected, and CRC stage at diagnosis in a CRC screening program. Methods: We analyzed all the invitations between 1 January 2019 and 31 December 2021. We defined the pandemic period as the period after 12 March 2020. We calculated the delay intervals (successive and all rounds), the rates of participation, adherence to colonoscopy after a positive fecal immunochemical test (FIT), and the diagnostic yield of colonoscopy, specifically of CRC and colorectal neoplasia (CRC and/or adenoma), as well as the CRC stage at diagnosis. Results: In the period analyzed, 976,187 invitations were sent (61.0% in the pandemic period), 439,687 FIT were returned (62.4% in the pandemic period) and 23,092 colonoscopies were performed (59.1% in the pandemic period). The colonoscopies were normal in 7378 subjects (32.4%) and CRC was detected in 916 subjects (4.0%). In successive rounds, the delay increased significantly by seven months during the pandemic period (p < 0.001). In all the invitations, the delay from the invitation to the colonoscopy increased significantly by 8 days (p < 0.001). Once adjusted for the confounding variables, the participation in the screening program increased significantly (OR = 1.1; 95% CI = 1.09–1.11), with no changes in the adherence to colonoscopy (OR = 0.9; 95% CI = 0.8–1.0). We found no differences in the diagnostic yield of colonoscopy in terms of CRC (OR = 0.90; 95% CI = 0.78–1.02) or colorectal neoplasia (OR = 0.98; 95% CI = 0.92–1.03) detection. Finally, we found no differences in the CRC stage at diagnosis (p = 0.2). Conclusions: Although the interruption of the CRC screening program due to the COVID pandemic increased the delays, it did not reduce participation, adherence to colonoscopy, or the diagnostic yield of colonoscopy. Full article

(This article belongs to the Section Cancer Causes, Screening and Diagnosis)

Open AccessArticle

Interrelationships among Tourism, Economic, and Environmental Time Series—The Case of Slovenia

Sergej Gricar

Violeta Šugar

and

Jasmina Starc

Sustainability 2023, 15(19), 14488; https://doi.org/10.3390/su151914488 (registering DOI) - 04 Oct 2023

Abstract

This study examines the relationship between CO₂ emissions and economic factors in the hospitality industry, covering the period from January 2000 to December 2021. The research findings reveal an association between prices, fiscal and monetary factors, and wages in the hospitality industry. CO₂ emissions contribute to environmental degradation and are among the external variables. To test the validity of their hypotheses, the researchers employ the principal components analysis method, using two main components and new regressors to explain most of the variances in a sample of 18 variables. The study employs monthly time series data to explore the links between the variables in the hospitality industry. The study results reveal a connection between shocks during the analysed period and increased CO₂ emissions. The period under review includes Slovenia’s European accession in 2004, adoption of the Euro in 2007, the financial crises in 2008/2009, economic expansion in the previous decade, and, most recently, the COVID-19 pandemic and the beginning of energy distortions. The study’s primary application involves processing 264 monthly observations, which provide an essential time series vector. The discussion section delves into the country’s sustainable tourism development concept, aligning with the Sustainable Development Goals (SDGs) Key Action 12. Full article

(This article belongs to the Special Issue Tourism and Sustainable Development Goals)

Open AccessReview

Nasopharynx Battlefield: Cellular Immune Responses Mediated by Midkine in Nasopharyngeal Carcinoma and COVID-19

and

Cancers 2023, 15(19), 4850; https://doi.org/10.3390/cancers15194850 - 04 Oct 2023

Abstract

Clinical evidence suggests that the severe respiratory illness coronavirus disease 2019 (COVID-19) is often associated with a cytokine storm that results in dysregulated immune responses. Prolonged COVID-19 positivity is thought to disproportionately affect cancer patients. With COVID-19 disrupting the delivery of cancer care, it is crucial to gain momentum and awareness of the mechanistic intersection between these two diseases. This review discusses the role of the cytokine midkine (MK) as an immunomodulator in patients with COVID-19 and nasopharyngeal carcinoma (NPC), both of which affect the nasal cavity. We conducted a review and analysis of immunocellular similarities and differences based on clinical studies, research articles, and published transcriptomic datasets. We specifically focused on ligand–receptor pairs that could be used to infer intercellular communication, as well as the current medications used for each disease, including NPC patients who have contracted COVID-19. Based on our findings, we recommend close monitoring of the MK axis to maintain the desirable effects of therapeutic regimens in fighting both NPC and COVID-19 infections. Full article

(This article belongs to the Special Issue Recent Advances in Rare Cancers: From Bench to Bedside and Back)

Open AccessArticle

Mathematical Investigation of the Infection Dynamics of COVID-19 Using the Fractional Differential Quadrature Method

M. Mohamed

S. M. Mabrouk

and

A. S. Rashed

Computation 2023, 11(10), 198; https://doi.org/10.3390/computation11100198 - 04 Oct 2023

Abstract

In recent times, the global community has been faced with the unprecedented challenge of the coronavirus disease (COVID-19) pandemic, which has had a profound and enduring impact on both global health and the global economy. The utilization of mathematical modeling has become an essential instrument in the characterization and understanding of the dynamics associated with infectious illnesses. In this study, the utilization of the differential quadrature method (DQM) was employed in order to anticipate the characterization of the dynamics of COVID-19 through a fractional mathematical model. Uniform and non-uniform polynomial differential quadrature methods (PDQMs) and a discrete singular convolution method (DSCDQM) were employed in the examination of the dynamics of COVID-19 in vulnerable, exposed, deceased, asymptomatic, and recovered persons. An analysis was conducted to compare the methodologies used in this study, as well as the modified Euler method, in order to highlight the superior efficiency of the DQM approach in terms of code-execution times. The results demonstrated that the fractional order significantly influenced the outcomes. As the fractional order tended towards unity, the anticipated numbers of vulnerable, exposed, deceased, asymptomatic, and recovered individuals increased. During the initial week of the inquiry, there was a substantial rise in the number of individuals who contracted COVID-19, which was primarily attributed to the disease’s high transmission rate. As a result, there was an increase in the number of individuals who recovered, in tandem with the rise in the number of infected individuals. These results highlight the importance of the fractional order in influencing the dynamics of COVID-19. The utilization of the DQM approach, characterized by its proficient code-execution durations, provided significant insights into the dynamics of COVID-19 among diverse population cohorts and enhanced our comprehension of the evolution of the pandemic. The proposed method was efficient in dealing with ordinary differential equations (ODEs), partial differential equations (PDEs), and fractional differential equations (FDEs), in either linear or nonlinear forms. In addition, the stability of the DQM and its validity were verified during the present study. Moreover, the error analysis showed that DQM has better error percentages in many applications than other relevant techniques. Full article

(This article belongs to the Special Issue 10th Anniversary of Computation—Computational Biology)

Open AccessArticle

The Impact of the COVID-19 Pandemic, Transport Accessibility, and Accommodation Accessibility on the Energy Intensity of Public Tourist Transport

Elżbieta Szaruga

Bartosz Pilecki

and

Marta Sidorkiewicz

Energies 2023, 16(19), 6949; https://doi.org/10.3390/en16196949 - 04 Oct 2023

Abstract

The article concerns the recognition of the impact of the COVID-19 pandemic, transport accessibility, and accommodation availability on the energy intensity of domestic travel by tourists using public transport in spatial and dynamic relations. The article formulated five research questions: (1) Does the improvement of transport accessibility reduce the energy intensity of public tourist transport? (2) Does the improvement of accommodation availability affect the reduction of the energy intensity of domestic tourist trips of Polish residents? (3) Has COVID-19 significantly changed the energy intensity of public tourist transport? (4) Are there any spatial effects of energy intensity of domestic tourist trips of Polish inhabitants resulting from the flow of tourists between regions (voivodeships) of Poland? (5) What would be the path of energy intensity patterns of public tourist transport if fortuitous events did not occur? The study covered 16 Polish voivodeships in 2017–2021. A comprehensive approach was used, combining exploratory analysis of spatial data with regional econometrics, spatial statistics, and spatial econometrics (gravitational model of spatial convergence of energy intensity of public transport of tourists). It has been verified that the energy intensity of domestic tourist travel by public transport is the most sensitive to the effects of the COVID-19 pandemic and the most flexible to changes in transport accessibility. It is less sensitive to changes in accommodation availability. The occurrence of spatial convergence, i.e., the blurring of differences in energy intensity patterns between the analyzed voivodeships, was also identified. An increase in energy intensity in voivodeships defined as neighboring voivodeships by 1% will result in an increase in energy intensity in the i-th voivodeship by 0.2688% on average, which results from the spatial effects of changes in mobility and tourist flows (tourism). Consumption patterns shaped in previous periods also have a significant impact on energy intensity. Full article

(This article belongs to the Special Issue New Insights into Transport Economics and Renewable Energy Sources)

Open AccessArticle

An Electronic Commerce Big Data Analytics Architecture and Platform

and

Appl. Sci. 2023, 13(19), 10962; https://doi.org/10.3390/app131910962 - 04 Oct 2023

Abstract

The COVID-19 pandemic significantly increased e-commerce growth, adding more than 218 billion US dollars to the United States e-commerce sales. With this significant growth, various operational challenges have appeared, including logistic difficulties and customer satisfaction. Businesses that strive to take advantage of increased e-commerce growth must understand data and rely on e-commerce analytics. The large scale of e-commerce data requires sophisticated information technology techniques and cyber-infrastructure to leverage and analyze. This study presents a big e-commerce data platform to address several challenges in e-commerce. The presented platform’s design is based on a distributed system architecture that supports e-commerce analytics applications using historical and real-time data and features a continuous feedback loop to observe the decision-making and evaluation processes to achieve the desired objectives. The platform was validated using two analytical applications. The first application was to identify the periods in which customers prefer to place orders, while the second was used to verify the big e-commerce data platform. The resulting insights and findings promote informed e-commerce decisions. Furthermore, viewing and acting on insight results and findings promote informed decisions that potentially benefit the e-commerce industry. The proposed platform can perform numerous e-commerce applications that potentially benefit the e-commerce industry. Full article

(This article belongs to the Section Computing and Artificial Intelligence)

State-of-the-Art Webinars on COVID-19

WEBINAR 1: How to Avoid a New Lockdown?

The first webinar in the series, held on 17 April 2020, saw both Prof. Dr. Antoine Flahault, Director of the Institute of Global Health, University of Geneva, Switzerland, and Prof. Dr. Evelyne Bischof, Associate Professor, Shanghai University of Medicine and Health Sciences, Shanghai, China and Research physician, University Hospital of Basel, Basel, Switzerland speak on this topic.