ABSTRACT
The recent COVID-19 pandemic showed that supply chain resilience is essential for continuity of many businesses, especially retail chains. However, there are still some challenges that have received little attention in the resilient supply chain network design (RSCND) literature. While numerous resilience strategies have been proposed to make supply chain networks resilient against disruptions, very few papers have discussed why and how those resilience strategies are selected out of many potential candidates given various sources of disruption, i.e., natural, man-made, and pandemic-oriented disruptions. The aim of this paper is to propose a multi-methodological approach, based on resource dependence theory and two-stage stochastic programming, for choosing the right resilience strategies in a RSCND problem considering their positive and negative synergistic effects under resource constraints. These interactions among resilience strategies can be referred to as supply chain dynamics. We then present a novel approach for determining the most suitable combination of candidate strategies with respect to these synergistic effects. The criticality of nodes and the susceptibility of the network in different echelons are also examined via simulating the disruptive risks in hidden and unexpected places. We provide a case study from the retail industry that illustrates the potentially significant impacts of network disruptions. Via extensive stress-testing, we show the benefits of applying multiple resilience capabilities simultaneously. Our findings demonstrate the importance of considering synergistic effects among resilience strategies under budget limitations for supply chain resilience. © 2022 Elsevier Ltd
ABSTRACT
The COVID-19 pandemic has caused serious concerns for people around the world. The COVID-19 is associated with respiratory failure, generation of reactive oxygen species (ROS), and the lack of antioxidants among patients. Specified ROS levels have an essential role as an adjuster of immunological responses and virus cleaners, but excessive ROS will oxidize membrane lipids and cellular proteins and quickly destroy virus-infected cells. It can also adversely damage normal cells in the lungs and even the heart, resulting in multiple organ failures. Given the above, a highly potent antioxidant therapy can be offered to reduce cardiac loss due to COVID-19. In modern medicine, nanoparticles containing antioxidants can be used as a high-performance therapy in reducing oxidative stress in the prevention and treatment of infectious diseases. This can provide a free and interactive tool to determine whether antioxidants and nanoantioxidants can be administered for COVID-19. More research and studies are needed to investigate and make definitive opinions about their medicinal uses.
ABSTRACT
Background: The pandemic of Covid-19 is spreading around the world. Extensive research is needed to focus on identifying the underlying causes of the disease. This study aimed to investigate the clinical and etiological symptoms of the Covid-19. Methods: This descriptive-analytical study, conducted on 510 infected patients in the infectious disease clinic of Imam Khomeini Hospital in Tehran from March 2019 to June 2020 for A period of Four months during the first wave of Covid-19 pandemic. The method of selecting patients was continuous and was divided into two groups of 179 inpatients and 331 outpatients based on lung scan and clinical symptoms. Demographic information, clinical signs, and risk factors were collected through a questionnaire and the data were statistically analyzed. Results: Symptoms such as fever, chills and cough were reported in the majority of patients in both groups, to such an extent that they were present in 176 (52%) of outpatients and in 101 (59%) of inpatients. The mean hemoglobin measured in hospitalized patients was lower, P=0.001). Vitamin D3 supplementation was reported in 30% of outpatients and in 16.5% of hospitalized patients (P=0.001). This means that vitamin D3 consumption is higher in the outpatient group. The results showed that Chronic diseases such as hypertension was 4.9 times more likely (OR=4.9, 95% CI2. 433-10.25, P=0.0001) and anemia with 22 times more likely (OR=22.905, 95% CI9. 355-56.083, P=0.000) to be effective in the severity of the disease. It seems Vitamin D3 intake has a supportive effect on reducing the severity of the disease and decreases the risk of the disease getting worse. Conclusion: Fever, chills and cough were important symptoms in identifying infected patients with Covid-19. According to the results of the present study and the findings of other studies, the supportive effect of vitamin D3 in reducing the severity of infectious diseases should be considered. Clinical trials with appropriate sample size are recommended to investigate the functional role of this vitamin in Reducing the severity of viral diseases of the respiratory tract.
ABSTRACT
The pandemic threat of COVID-19 causes serious concern for people and world organizations. The effect of Coronavirus disease on the lifestyle and economic status of humans is undeniable, and all of the researchers (biologists, pharmacists, physicians, and chemists) can help decrease its destructive effects. The molecular docking approach can provide a fast prediction of the positive influence the targets on the COVID-19 outbreak. In this work, we choose resveratrol (RV) derivatives (22 cases) and two newly released coordinate structures for COVID-19 as receptors [Papain-like Protease of SARS CoV-2 (PBD ID: 6W9C) and 2019-nCoV RNA-dependent RNA Polymerase (PBD ID: 6M71)]. The results show that conformational isomerism is significant and useful parameter for docking results. A wide spectrum of interactions such as Van der Waals, conventional hydrogen bond, Pi-donor hydrogen bond, Pi-Cation, Pi-sigma, Pi-Pi stacked, Amide-Pi stacked and Pi-Alkyl is detected via docking of RV derivatives and COVID-19 receptors. The potential inhibition effect of RV-13 (-184.99 kj/mol), and RV-12 (-173.76 kj/mol) is achieved at maximum value for 6W9C and 6M71, respectively.