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1.
Front Med (Lausanne) ; 10: 1126491, 2023.
Article in English | MEDLINE | ID: covidwho-2301042

ABSTRACT

The COVID-19 pandemic is ongoing and places a substantial burden on healthcare systems worldwide. As we further shed light on different disease characteristics, we identify more and more groups of people at higher risk of poor COVID-19 outcomes. Metabolic-associated fatty liver disease (MAFLD) (previously non-alcoholic fatty liver disease or NAFLD) is a common metabolic disorder characterized by fat accumulation and liver fibrosis. Given its close correlation with metabolic syndrome, an established risk factor for severe COVID-19, it is necessary to investigate its interplay with the novel coronavirus. In this study, we review the available data on COVID-19 prognosis, treatment and prevention options in patients with MAFLD, and the effect that the disease and the pandemic have on MAFLD care. Furthermore, we point out the gaps in the current literature to accentuate the work that needs to be done to improve MAFLD care during the pandemic and beyond.

3.
J Hepatol ; 2022 Nov 02.
Article in English | MEDLINE | ID: covidwho-2302356

ABSTRACT

BACKGROUND & AIMS: The LIVIFY trial investigated the safety, tolerability, and efficacy, of Vonafexor, a second-generation, non-bile acid farnesoid X receptor agonist in patients with suspected fibrotic non-alcoholic steatohepatitis (NASH). METHODS: This double-blind phase 2a study was conducted in two parts. Patients were randomised (1:1:1:1) to receive placebo, Vonafexor 100 mg twice daily (VONA-100BID), Vonafexor 200 mg once daily (VONA-200QD), or 400 mg Vonafexor QD (VONA-400QD) in Part A (safety run-in, pharmacokinetics/pharmacodynamics) or placebo, Vonafexor 100 mg QD (VONA-100QD), or VONA-200QD (1:1:1) in Part B. Efficacy endpoints were reduction in liver fat content (LFC) from baseline to Week 12 by magnetic resonance imaging proton density fat fraction (MRI-PDFF, primary), imaging biomarker of fibrotic steatohepatitis (corrected T1 signal), and liver enzymes. RESULTS: One hundred and twenty patients were randomised (Part A, n=24; Part B, n=96). In Part B, there was a significant reduction in least-square mean (SE) absolute change in LFC from baseline to Week 12 for VONA-100QD, (-6.3% [0.9]), VONA-200QD (-5.4% [0.9]), versus placebo (-2.3% [0.9], p=0.002 and 0.012, respectively). A >30% relative LFC reduction was achieved by 50.0% and 39.3% of patients in the VONA-100QD and VONA-200QD arms, respectively, but only in 12.5% in the placebo arm. Reductions in body weight, liver enzymes, and corrected T1 were also observed with Vonafexor. Creatinine based glomerular filtration rate (eGFR) improved in the active arms but not the placebo arm. Mild to moderate generalised pruritus was reported in 6.3%, 9.7%, and 18.2% of subjects in the placebo, VONA-100QD, and VONA-200QD arms, respectively. CONCLUSIONS: In patients with suspected fibrotic NASH, Vonafexor was safe and induced potent liver fat reduction, improvement in liver enzymes, weight loss, and a possible renal benefit. CLINICAL TRIAL NUMBER (EUDRACT): 2018-003119-22. GOV IDENTIFIER: NCT03812029. IMPACT AND IMPLICATIONS: NASH has become a leading cause for chronic liver disease and patients are also at higher risk for the development of chronic kidney disease. There are no approved therapies and only few options to treat this population. LIVIFY Phase 2a trial results show that single daily administration of oral Vonafexor, a FXR agonist, leads in the short term to a reduction in liver fat, liver enzymes, fibrosis biomarkers, body weight and abdominal circumference, and a possible improvement in kidney function, while possible mild moderate pruritus (a peripheral FXR class effect) and an LDL-Cholesterol increase are manageable with lower doses and statins. These results support exploration in longer and larger trials to ultimately provide therapies for the unmet medical need in NASH.

4.
2022 Winter Simulation Conference, WSC 2022 ; 2022-December:484-495, 2022.
Article in English | Scopus | ID: covidwho-2275383

ABSTRACT

The COVID-19 pandemic has radically transformed the work-from-home (WFH) paradigm, and expanded an organization's cyber-vulnerability space. We propose a novel strategic method to quantify the degree of sub-optimal cybersecurity in an organization of employees, all of whom work in heterogeneous WFH 'siloes'. Specifically, we model the per-unit cost of asymmetric WFH employees to invest in security-improving effort units as time-discounted exponential martingales over time, and derive as benchmark - the centrally-planned socially optimal aggregate employee effort at any given time instant. We then derive the time-varying strategic Nash equilibrium amount of aggregate employee effort in cybersecurity in a distributed setting. The time-varying ratio of these centralized and distributed estimates quantifies the free riding dynamics, i.e., security sub-optimality, within an organization. Rigorous estimates of the degree of sub-optimal cybersecurity will drive organizational policy makers to design appropriate (customized) solutions that voluntarily incentivize WFH employees to invest in required cybersecurity best practices. © 2022 IEEE.

5.
Cent Eur J Oper Res ; : 1-20, 2023 Mar 14.
Article in English | MEDLINE | ID: covidwho-2252417

ABSTRACT

In this paper we analyze dynamic interactions in a monetary union with three fiscal players (the governments of the countries concerned) and a common central bank in the presence of exogenous shocks. The model is calibrated for the euro area and includes a fiscally more solid core block denoted as country 1 as well as a fiscally less solid periphery block represented by countries 2 and 3. Introducing two periphery countries allows us to capture different attitudes of the periphery countries towards the goal of sustainable fiscal performance. Moreover, different coalition scenarios are modelled in this study including a fiscal union, a coalition of periphery countries and a coalition of fiscal-stability oriented countries. The exogenous shocks are calibrated in such a way as to describe the last major crises in the euro area, namely the financial crisis, the European sovereign debt crisis, the Covid-19 crisis, and the Ukraine war (energy price) crisis. Using the OPTGAME algorithm we calculate a cooperative Pareto and non-cooperative feedback Nash equilibrium solutions for the modelled scenarios. The fully cooperative solution yields the best results. The different non-cooperative scenarios allow insights into the underlying trade-off between economic growth, price stability and fiscal stability.

6.
Nanomedicine (Lond) ; 18(1): 67-84, 2023 01.
Article in English | MEDLINE | ID: covidwho-2250475

ABSTRACT

Nanomedicines are revolutionizing healthcare as recently demonstrated by the Pfizer/BioNTech and Moderna COVID-2019 vaccines, with billions of doses administered worldwide in a safe manner. Nonalcoholic fatty liver disease is the most common noncommunicable chronic liver disease, posing a major growing challenge to global public health. However, due to unmet diagnostic and therapeutic needs, there is great interest in the development of novel translational approaches. Nanoparticle-based approaches offer novel opportunities for efficient and specific drug delivery to liver cells, as a step toward precision medicines. In this review, the authors highlight recent advances in nanomedicines for the generation of novel diagnostic and therapeutic tools for nonalcoholic fatty liver disease and related liver diseases.


Chronic liver diseases are a growing concern for global public health since they can affect up to 25% of the global adult population. Currently, there is no effective treatment or cure for these diseases. Nanometer-sized capsules can be loaded with drugs and more accurately deliver these drugs to their sites of action. They help improve the availability of medicines to the liver and have the potential to reduce their side effects. Here, the authors discuss recent advances to explain how nanotechnology can help improve the benefits of existing medicines for liver disease therapy.


Subject(s)
COVID-19 , Nanoparticles , Non-alcoholic Fatty Liver Disease , Humans , Non-alcoholic Fatty Liver Disease/drug therapy , Non-alcoholic Fatty Liver Disease/diagnosis , Nanomedicine , Drug Delivery Systems , Nanoparticles/therapeutic use
7.
JHEP Rep ; 5(5): 100703, 2023 May.
Article in English | MEDLINE | ID: covidwho-2240261

ABSTRACT

Background & Aims: Bacterial infections affect survival of patients with cirrhosis. Hospital-acquired bacterial infections present a growing healthcare problem because of the increasing prevalence of multidrug-resistant organisms. This study aimed to investigate the impact of an infection prevention and control programme and coronavirus disease 2019 (COVID-19) measures on the incidence of hospital-acquired infections and a set of secondary outcomes, including the prevalence of multidrug-resistant organisms, empiric antibiotic treatment failure, and development of septic states in patients with cirrhosis. Methods: The infection prevention and control programme was a complex strategy based on antimicrobial stewardship and the reduction of patient's exposure to risk factors. The COVID-19 measures presented further behavioural and hygiene restrictions imposed by the Hospital and Health Italian Sanitary System recommendations. We performed a combined retrospective and prospective study in which we compared the impact of extra measures against the hospital standard. Results: We analysed data from 941 patients. The infection prevention and control programme was associated with a reduction in the incidence of hospital-acquired infections (17 vs. 8.9%, p <0.01). No further reduction was present after the COVID-19 measures had been imposed. The impact of the infection prevention and control programme remained significant even after controlling for the effects of confounding variables (odds ratio 0.44, 95% CI 0.26-0.73, p = 0.002). Furthermore, the adoption of the programme reduced the prevalence of multidrug-resistant organisms and decreased rates of empiric antibiotic treatment failure and the development of septic states. Conclusions: The infection prevention and control programme decreased the incidence of hospital-acquired infections by nearly 50%. Furthermore, the programme also reduced the prevalence of most of the secondary outcomes. Based on the results of this study, we encourage other liver centres to adopt infection prevention and control programmes. Impact and implications: Infections are a life-threatening problem for patients with liver cirrhosis. Moreover, hospital-acquired infections are even more alarming owing to the high prevalence of multidrug-resistant bacteria. This study analysed a large cohort of hospitalised patients with cirrhosis from three different periods. Unlike in the first period, an infection prevention programme was applied in the second period, reducing the number of hospital-acquired infections and containing multidrug-resistant bacteria. In the third period, we imposed even more stringent measures to minimise the impact of the COVID-19 outbreak. However, these measures did not result in a further reduction in hospital-acquired infections.

8.
Comput Ind Eng ; 177: 108975, 2023 Mar.
Article in English | MEDLINE | ID: covidwho-2165161

ABSTRACT

The global economy has experienced a tremendous shock caused by the Covid-19 pandemic and its effects on the normal activities of SMEs, which provide essential driving economic force. Considering that there is currently no precise prediction about the end of this pandemic, many SMEs must make critical decisions about whether to remain in the market during the pandemic or to leave it, investing their assets in a more secure sector of the economy. However, in order to convince SMEs to remain in the market, thus maintaining the damaged economy, governments may variously apply punitive or supportive measures. In this regard, the interaction between SMEs strategies and government measures can be considered as an evolutionary game, in which the governments impose various policies after observing the evolutionary behaviors of SMEs. An evolutionary stable strategy (ESS) is derived through a replicator dynamic system, and the available payoff of each player is calculated by Nash equilibrium (NA). Finally, a numerical example is presented, and related managerial insights are proposed at the end of the current study. For instance, contrary to general belief, it can be inferred from investigating possible scenarios that punitive policies are more effective than supportive measures in convincing SMEs to remain in the market.

9.
Trop Med Infect Dis ; 7(12)2022 Dec 07.
Article in English | MEDLINE | ID: covidwho-2155271

ABSTRACT

Patients with co-morbidities like cirrhosis are at risk of worse outcome from COVID-19 infection. Given limited prior studies, we evaluated outcomes associated with COVID-19 infection in alcoholic and non-alcoholic steatohepatitis cirrhotic (CC+) versus cirrhotic without COVID-19 (CC−). We performed retrospective analysis of 822,604 patients including 28,610 COVID-19 patients from the National Inpatient Sample database with alcoholic and NASH cirrhosis enrolled between 1 January 2020 to 31 December 2020, with univariate and multivariate regression analyses. Primary outcome was mortality and secondary outcomes was mechanical ventilation, vasopressor use, length of stay, hospitalization expense and predictors of mortality. In-hospital mortality was three time higher in the CC+ group compared to those in the CC− group(18.6% vs. 5.96%, p < 0.001, adjusted odds ratio (OR)3.39 (95% 3.08−3.74 CI). Hospitalization was more likely for underrepresented racial and ethnic groups with COVID-19 and cirrhosis. CC+ group had over twice the rates of mechanical ventilation (19.92% vs. 9.07%, adjusted OR 2.71 2.71 (95% 2.51−2.93 CI)),1.7 times likelihood of receiving vasopressors (4.12% vs. 2.45%, p < 0.001, adjusted OR 1.71 (95% CI 1.46−2.01). COVID-19 is associated with increased mortality in patients with alcoholic and NASH cirrhosis, and patients with alcoholic cirrhosis and COVID-19 have a slightly higher mortality compared to NASH cirrhosis.

10.
Int J Mol Sci ; 23(22)2022 Nov 08.
Article in English | MEDLINE | ID: covidwho-2110124

ABSTRACT

Cholesterol synthesis occurs in almost all cells, but mainly in hepatocytes in the liver. Cholesterol is garnering increasing attention for its central role in various metabolic diseases. In addition, cholesterol is one of the most essential elements for cells as both a structural source and a player participating in various metabolic pathways. Accurate regulation of cholesterol is necessary for the proper metabolism of fats in the body. Disturbances in cholesterol homeostasis have been linked to various metabolic diseases, such as hyperlipidemia and non-alcoholic fatty liver disease (NAFLD). For many years, the use of synthetic chemical drugs has been effective against many health conditions. Furthermore, from ancient to modern times, various plant-based drugs have been considered local medicines, playing important roles in human health. Phytochemicals are bioactive natural compounds that are derived from medicinal plants, fruit, vegetables, roots, leaves, and flowers and are used to treat a variety of diseases. They include flavonoids, carotenoids, polyphenols, polysaccharides, vitamins, and more. Many of these compounds have been proven to have antioxidant, anti-inflammatory, antiobesity and antihypercholesteremic activity. The multifaceted role of phytochemicals may provide health benefits to humans with regard to the treatment and control of cholesterol metabolism and the diseases associated with this disorder, such as NAFLD. In recent years, global environmental climate change, the COVID-19 pandemic, the current war in Europe, and other conflicts have threatened food security and human nutrition worldwide. This further emphasizes the urgent need for sustainable sources of functional phytochemicals to be included in the food industry and dietary habits. This review summarizes the latest findings on selected phytochemicals from sustainable sources-algae and edible mushrooms-that affect the synthesis and metabolism of cholesterol and improve or prevent NAFLD.


Subject(s)
Agaricales , COVID-19 , Non-alcoholic Fatty Liver Disease , Humans , Non-alcoholic Fatty Liver Disease/drug therapy , Agaricales/chemistry , Pandemics , Phytochemicals/pharmacology , Phytochemicals/therapeutic use , Cholesterol/therapeutic use
11.
2022 American Control Conference, ACC 2022 ; 2022-June:568-573, 2022.
Article in English | Scopus | ID: covidwho-2056822

ABSTRACT

The COVID-19 lockdowns have created a significant socioeconomic impact on our society. In this paper, we propose a population vaccination game framework, called EPROACH, to design policies for reopenings that guarantee post-opening public health safety. In our framework, a population of players decides whether to vaccinate based on the public and private information they receive. The reopening is captured by the switching of the game state. The insights obtained from our framework include the appropriate vaccination coverage threshold for safe-reopening and information-based methods to incentivize individual vaccination decisions. In particular, our framework bridges the modeling of the strategic behaviors of the populations and the spreading of infectious diseases. This integration enables finding the threshold which guarantees a disease-free epidemic steady state under the population's Nash equilibrium vaccination decisions. The equilibrium vaccination decisions depend on the information received by the agents. It makes the steady-state epidemic severity controllable through information. We find that the externalities created by reopening lead to the coordination of the players in the population and result in a unique Nash equilibrium. We use numerical experiments to corroborate the results and illustrate the design of public information for responsible reopening. © 2022 American Automatic Control Council.

12.
Applied Mathematics and Computation ; 434:127453, 2022.
Article in English | ScienceDirect | ID: covidwho-1976971

ABSTRACT

In this paper, we present a game-theoretic model describing voluntary social distancing during the spread of an epidemic. The payoffs of the agents depend on the social distancing they practice and on the probability of getting infected. We consider two types of agents: the non-vulnerable agents with a small cost if they get infected and the vulnerable agents with a higher cost. For the modeling of the epidemic outbreak, we consider a variant of the SIR (Susceptible-Infected-Removed) model involving populations of susceptible, infected, and removed persons of vulnerable and non-vulnerable types. The Nash equilibria of this social distancing game are studied. The main contribution of this work is the analysis of the case where the players, desiring to achieve a low social inequality, pose a bound on the variance of the payoffs. In this case, we introduce and characterize a notion of Generalized Nash Equilibrium (GNE) for games with a continuum of players and provide characterizations for this type of GNE. It turns out that often there is a continuum of GNE. However, among the GNE, for a given value of the variance bound, there is one that Pareto dominates the others. We also provide conditions under which a more restrictive variance constraint benefits all the game participants. Furthermore, we describe a bargaining-based algorithm for choosing the variance constraint. Through numerical studies, we show that inequality constraints result in a slower spread of the epidemic and an improved cost for the vulnerable players. Furthermore, we present some examples where inequality constraints are also beneficial for non-vulnerable players.

13.
Nonlinear Dynamics ; 2022.
Article in English | Scopus | ID: covidwho-1959060

ABSTRACT

We analyze a mathematical model of COVID-19 transmission control, which includes the interactions among different groups of the population: vaccinated, susceptible, exposed, infectious, super-spreaders, hospitalized and fatality, based on a system of ordinary differential equations, which describes compartment model of a disease and its treatment. The aim of the model is to predict the development disease under different types of treatment during some fixed time period. We develop a game theoretic approach and a dual dynamic programming method to formulate optimal conditions of the treatment for an administration of a vaccine. Next, we calculate numerically an optimal treatment. © 2022, The Author(s), under exclusive licence to Springer Nature B.V.

14.
Gut Microbes ; 14(1): 2100200, 2022.
Article in English | MEDLINE | ID: covidwho-1927236

ABSTRACT

Obese patientss with nonalcoholic steatohepatitis (NASH) are particularly prone to developing severe forms of coronavirus disease 19 (COVID-19). The gut-to-lung axis is critical during viral infections of the respiratory tract, and a change in the gut microbiota's composition might have a critical role in disease severity. Here, we investigated the consequences of infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on the gut microbiota in the context of obesity and NASH. To this end, we set up a nutritional model of obesity with dyslipidemia and NASH in the golden hamster, a relevant preclinical model of COVID-19. Relative to lean non-NASH controls, obese NASH hamsters develop severe inflammation of the lungs and liver. 16S rRNA gene profiling showed that depending on the diet, SARS-CoV-2 infection induced various changes in the gut microbiota's composition. Changes were more prominent and transient at day 4 post-infection in lean animals, alterations still persisted at day 10 in obese NASH animals. A targeted, quantitative metabolomic analysis revealed changes in the gut microbiota's metabolic output, some of which were diet-specific and regulated over time. Our results showed that specifically diet-associated taxa are correlated with disease parameters. Correlations between infection variables and diet-associated taxa highlighted a number of potentially protective or harmful bacteria in SARS-CoV-2-infected hamsters. In particular, some taxa in obese NASH hamsters (e.g. Blautia and Peptococcus) were associated with pro-inflammatory parameters in both the lungs and the liver. These taxon profiles and their association with specific disease markers suggest that microbial patterns might influence COVID-19 outcomes.


Subject(s)
COVID-19 , Gastrointestinal Microbiome , Non-alcoholic Fatty Liver Disease , Animals , Cricetinae , Non-alcoholic Fatty Liver Disease/microbiology , Obesity/complications , Obesity/microbiology , RNA, Ribosomal, 16S/genetics , SARS-CoV-2
15.
Mathematics ; 10(10):1723, 2022.
Article in English | ProQuest Central | ID: covidwho-1870945

ABSTRACT

The free-riding behavior of companies that do not act will bring losses to companies that provide services. A market consists of two secondary supply chains: manufacturers and retailers. Each supply chain can choose to adopt promotional strategies to expand its market demand. This paper constructs the centralized decision-making in the supply chain and the Nash game competition model between supply chains and primarily studies the impact of risk aversion and the free-riding coefficient on supply chain pricing, promotion strategy selection, and expected utility. We show that the supply chain with high-risk aversion has relatively low pricing, but the demand and a total expected utility are high. We also identify that, on the premise of the same risk aversion degree of the two supply chains, when the free-riding coefficient between the chains is small and equal, the supply chain tends to implement the promotion strategy. When consumers have the same preference for the products of two retailers, the pricing of the free-riding supply chain increases with the increase in the free-riding coefficient, while the supply chain with a promotion strategy is the opposite. Based on the numerical results, we further give the optimal one-way free-riding coefficient when the two supply chains have the same degree of risk aversion;when there is a bidirectional free-riding behavior in the market, competition among supply chains gradually tends to the first two scenarios.

16.
J Clin Exp Hepatol ; 12(5): 1320-1327, 2022.
Article in English | MEDLINE | ID: covidwho-1867325

ABSTRACT

Background: Fatty liver has been shown to be associated with severe COVID-19 disease without any impact on mortality. This is based on heterogenous criteria for defining both fatty liver as well as the severity parameters. This study aimed to study the impact of fatty liver on the mortality and severity of disease in patients with COVID-19 pneumonia. Methods: In a case control study design, patients with COVID-19 pneumonia (COVID-19 computed tomography severity index [CTSI] on high-resolution computed tomography chest of ≥1) with fatty liver (defined as liver to spleen attenuation index ≤5 on noncontrast computed tomography cuts of upper abdomen) were compared with those without fatty liver. The primary outcome measure was in-hospital mortality, and the secondary outcome measures were CTSI score, need for intensive care unit (ICU) care, need for ventilatory support, duration of ICU stay, and duration of hospital stay. Results: Of 446 patients with COVID-19 pneumonia, 289 (64.7%)admitted to Max Hospital, Saket, India, between January 1, 2021, and October 30, 2021, had fatty liver. Fifty-nine of 446 patients died during the index admission. In-hospital mortality was not different between patients with fatty liver (38 [13.24%]) or without fatty liver (21 [13.81%]). COVID-19 CTSI score was found to be significantly higher among patients who had fatty liver (13.40 [5.16] vs 11.81 [5.50]; P = 0.003). There was no difference in the requirement of ICU (94 [32%] vs 62 [39.49%]; P = 0.752), requirement of ventilatory support (27 [9.34%] vs 14 [8.91%]; P = 0.385), duration of ICU stay (8.29 [6.87] vs 7.07 [5.71] days; P = 0.208), and duration of hospital stay (10.10 [7.14] vs 10.69 [8.13] days; P = 0.430) between the groups with fatty liver or no fatty liver. Similarly, no difference was found in primary or secondary outcomes measure between the group with severe fatty liver vs mild/moderate or no fatty liver. High total leucocyte count and Fibrosis-4 (FIB-4) index were independently associated with mortality. Conclusions: Fatty liver may not be associated with increased mortality or clinical morbidity in patients who have COVID-19 pneumonia.

17.
International Journal of Molecular Sciences ; 23(9):4822, 2022.
Article in English | ProQuest Central | ID: covidwho-1842716

ABSTRACT

Obesity is one of the greatest health challenges affecting children of all ages and ethnicities. Almost 19% of children and adolescents worldwide are overweight or obese, with an upward trend in the last decades. These reports imply an increased risk of fat accumulation in hepatic cells leading to a series of histological hepatic damages gathered under the acronym NAFLD (Non-Alcoholic Fatty Liver Disease). Due to the complex dynamics underlying this condition, it has been recently renamed as ‘Metabolic Dysfunction Associated Fatty Liver Disease (MAFLD)’, supporting the hypothesis that hepatic steatosis is a key component of the large group of clinical and laboratory abnormalities of Metabolic Syndrome (MetS). This review aims to share the latest scientific knowledge on MAFLD in children in an attempt to offer novel insights into the complex dynamics underlying this condition, focusing on the novel molecular aspects. Although there is still no treatment with a proven efficacy for this condition, starting from the molecular basis of the disease, MAFLD’s therapeutic landscape is rapidly expanding, and different medications seem to act as modifiers of liver steatosis, inflammation, and fibrosis.

18.
Xitong Gongcheng Lilun yu Shijian/System Engineering Theory and Practice ; 42(3):724-737, 2022.
Article in Chinese | Scopus | ID: covidwho-1791804

ABSTRACT

The code sharing is the popular and effective cooperation of the airlines. First, this paper applies the spokes model to describe the different preferences of passengers for three airlines, and proposes the twostage game model and the simple method for the code sharing agreement choosing stage and the tickets' pricing stage under the free-sale model. Second, we use the numerical example to show the feasibility of the proposed models and method. By comparison and analysis, the Nash equilibrium situations of the two-stage game can be obtained. This study demonstrates: The code sharing agreement saves the total operating cost, but it raises the average airfare of the aviation market, so that the airlines' profits increase and the passengers' surpluses decrease;the government should promote the realization of better Nash equilibrium situation in order to maximize the total social welfare;to further improve the total social welfare during the period of Corona Virus Disease-19, the government could give the airlines some cost subsidies or adjust the passengers' psychological costs. Therefore, this paper provides significant theoretical and methodical supports to optimize the choices of the code sharing agreements and to improve the total social welfare in the aviation market. © 2022, Editorial Board of Journal of Systems Engineering Society of China. All right reserved.

19.
Biomedicines ; 10(3)2022 Mar 17.
Article in English | MEDLINE | ID: covidwho-1760358

ABSTRACT

In patients with non-alcoholic fatty liver disease (NAFLD) with or without type 2 diabetes mellitus (T2DM), alpha-2 macroglobulin (A2M), apolipoprotein A1 (ApoA1), and haptoglobin are associated with the risk of liver fibrosis, inflammation (NASH), and COVID-19. We assessed if these associations were worsened by T2DM after adjustment by age, sex, obesity, and COVID-19. Three datasets were used: the "Control Population", which enabled standardization of protein serum levels according to age and sex (N = 27,382); the "NAFLD-Biopsy" cohort for associations with liver features (N = 926); and the USA "NAFLD-Serum" cohort for protein kinetics before and during COVID-19 (N = 421,021). The impact of T2DM was assessed by comparing regression curves adjusted by age, sex, and obesity for the liver features in "NAFLD-Biopsy", and before and during COVID-19 pandemic peaks in "NAFLD-Serum". Patients with NAFLD without T2DM, compared with the values of controls, had increased A2M, decreased ApoA1, and increased haptoglobin serum levels. In patients with both NAFLD and T2DM, these significant mean differences were magnified, and even more during the COVID-19 pandemic in comparison with the year 2019 (all p < 0.001), with a maximum ApoA1 decrease of 0.21 g/L in women, and a maximum haptoglobin increase of 0.17 g/L in men. In conclusion, T2DM is associated with abnormal levels of A2M, ApoA1, and haptoglobin independently of NAFLD, age, sex, obesity, and COVID-19.

20.
5th International Conference on Education and E-Learning, ICEEL 2021 ; : 142-148, 2021.
Article in English | Scopus | ID: covidwho-1731325

ABSTRACT

This paper examines the impact of learning environments, educators’ attention, and students’ personal qualities on the outcomes of online learning. To approach conclusions, this paper describes the heterogeneous effect of these three types of factors on online learning outcomes and employs a fixed-effect regression to examine what exact factors constitute a good learning environment, appropriate educators’ attention and personal qualities that benefit students’ learning efficiency. The fixed-effect regression is applied on data of students’ answers to questionnaires and their final exam scores collected anonymously at three high schools in northern China during COVID-19 quarantine periods when Chinese high schools all conduct lessons and mid-term exams online but the final exam off-line, which is a major differentiation factor of this study. This paper contributes to three major findings: students who are more self-disciplined benefit more from the improvement of learning environments, practicing sports regularly improves online learning outcomes, and educators should find a balance between ensuring students are focused and not giving students too much pressure. © 2021 Association for Computing Machinery.

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