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1.
Fractal and Fractional ; 6(8):410, 2022.
Article in English | MDPI | ID: covidwho-1957259

ABSTRACT

This study establishes a compartment model for the categorized COVID-19 risk area. In this model, the compartments represent administrative regions at different transmission risk levels instead of individuals in traditional epidemic models. The county-level regions are partitioned into High-risk (H), Medium-risk (M), and Low-risk (L) areas dynamically according to the current number of confirmed cases. These risk areas are communicable by the movement of individuals. An LMH model is established with ordinary differential equations (ODEs). The basic reproduction number R0 is derived for the transmission of risk areas to determine whether the pandemic is controlled. The stability of this LHM model is investigated by a Lyapunov function and Poincare–Bendixson theorem. We prove that the disease-free equilibrium (R0 < 1) is globally asymptotically stable and the disease will die out. The endemic equilibrium (R0 > 1) is locally and globally asymptotically stable, and the disease will become endemic. The numerical simulation and data analysis support the previous theoretical proofs. For the first time, the compartment model is applied to investigate the dynamics of the transmission of the COVID-19 risk area. This work should be of great value in the development of precision region-specific containment strategies.

2.
Frontiers in medicine ; 9, 2022.
Article in English | EuropePMC | ID: covidwho-1871027

ABSTRACT

Background People's lifestyles may have changed during the COVID-19 pandemic, which may have a profound impact on pregnant women and newborns. This study aims to assess the effects of the COVID-19 pandemic on uninfected pregnant women and their newborns, including potential environmental factors. Methods We retrospectively analyzed the pregnancy complications of 802 cases in the pandemic group and 802 controls in the pre-pandemic group in a matched nested case-control study, and evaluated the association with sociodemographic features, lifestyles, and other factors in 311 pregnant women with adverse pregnancy outcomes. Results Compared to the pre-pandemic group, the rates of anemia, vaginitis, shoulder dystocia, and adverse pregnancy outcomes such as preterm birth were increased in the pandemic group. After controlling for the covariates, we observed a higher risk of adverse pregnancy outcomes in the pandemic group. Pregnant women with adverse pregnancy outcomes had an increased rate of anemia and vaginal candidiasis. Conclusion COVID-19 pandemic has profound effects on adverse pregnancy outcomes, suggesting the importance of ensuring regular prenatal checkups and keeping a healthy lifestyle.

3.
J Dermatolog Treat ; 33(2): 1191-1192, 2022 03.
Article in English | MEDLINE | ID: covidwho-1778768
4.
Fractal and Fractional ; 6(4):197, 2022.
Article in English | MDPI | ID: covidwho-1776180

ABSTRACT

The large proportion of asymptomatic patients is the major cause leading to the COVID-19 pandemic which is still a significant threat to the whole world. A six-dimensional ODE system (SEIAQR epidemical model) is established to study the dynamics of COVID-19 spreading considering infection by exposed, infected, and asymptomatic cases. The basic reproduction number derived from the model is more comprehensive including the contribution from the exposed, infected, and asymptomatic patients. For this more complex six-dimensional ODE system, we investigate the global and local stability of disease-free equilibrium, as well as the endemic equilibrium, whereas most studies overlooked asymptomatic infection or some other virus transmission features. In the sensitivity analysis, the parameters related to the asymptomatic play a significant role not only in the basic reproduction number R0. It is also found that the asymptomatic infection greatly affected the endemic equilibrium. Either in completely eradicating the disease or achieving a more realistic goal to reduce the COVID-19 cases in an endemic equilibrium, the importance of controlling the asymptomatic infection should be emphasized. The three-dimensional phase diagrams demonstrate the convergence point of the COVID-19 spreading under different initial conditions. In particular, massive infections will occur as shown in the phase diagram quantitatively in the case R0>1. Moreover, two four-dimensional contour maps of Rt are given varying with different parameters, which can offer better intuitive instructions on the control of the pandemic by adjusting policy-related parameters.

5.
Sustainability ; 14(6):3520, 2022.
Article in English | ProQuest Central | ID: covidwho-1765892

ABSTRACT

There has been extensive research on the association between environmental attitudes and outdoor recreation (or nature-based leisure activities) since the 1970s. There is now considerable evidence to support the claim that spending time in nature leads to greater connectedness to nature and thereby greater pro-environmental attitudes and behavior. However, there is an absence of research focused specifically on the association between outdoor recreation and concern for climate change, which is arguably the most pressing environmental problem facing the world today. We build on previous research by using the 2021 General Social Survey and structural equation modeling to analyze the association between frequency of engaging in outdoor recreation and concern for climate change among adults in the United States, with special attention to the role of enjoying being in nature. Controlling for other factors, we find that frequency of outdoor recreation has a positive, significant effect on climate change concern, but only indirectly via enjoyment of nature. Individuals who more frequently engage in outdoor recreation activities tend to report a greater sense of enjoyment of being outside in nature, and this enjoyment of nature is associated with a higher level of concern for climate change.

6.
Int J Mol Sci ; 22(23)2021 Nov 30.
Article in English | MEDLINE | ID: covidwho-1559206

ABSTRACT

Cytokine storm is a phenomenon characterized by strong elevated circulating cytokines that most often occur after an overreactive immune system is activated by an acute systemic infection. A variety of cells participate in cytokine storm induction and progression, with profiles of cytokines released during cytokine storm varying from disease to disease. This review focuses on pathophysiological mechanisms underlying cytokine storm induction and progression induced by pathogenic invasive infectious diseases. Strategies for targeted treatment of various types of infection-induced cytokine storms are described from both host and pathogen perspectives. In summary, current studies indicate that cytokine storm-targeted therapies can effectively alleviate tissue damage while promoting the clearance of invading pathogens. Based on this premise, "multi-omics" immune system profiling should facilitate the development of more effective therapeutic strategies to alleviate cytokine storms caused by various diseases.


Subject(s)
COVID-19/pathology , Cytokine Release Syndrome/drug therapy , Cytokine Release Syndrome/pathology , Cytokines/blood , Sepsis/pathology , Anti-Inflammatory Agents/therapeutic use , Bacteria/immunology , Bacterial Infections/pathology , Cytokines/metabolism , Humans , Inflammation/pathology , Macrophages/immunology , SARS-CoV-2/immunology , Sepsis/microbiology
8.
Agricultural & Forest Meteorology ; 308:N.PAG-N.PAG, 2021.
Article in English | Academic Search Complete | ID: covidwho-1397128

ABSTRACT

• Develop a within-growing season yield forecast system with random forest model. • Random forest model performs well in predicting grain yield in China. • We identified the most important stage-specific predictors determining crop yield. • The most important variable influencing yields varied with crop types. Accurate and timely crop yield forecasts can provide essential information to make conclusive agricultural policies and to conduct investments. Recent studies have used different machine learning techniques to develop such yield forecast systems for single crops at regional scales. However, no study has used multiple sources of environmental predictors (climate, soil, and vegetation) to forecast yields for three major crops in China. In this study, we adopted 7-year observed crop yield data (2013–2019) for three major grain crops (wheat, maize, and rice) across China, and three major data sets including climate, vegetation indices, and soil properties were used to develop a dynamic yield forecasting system based on the random forest (RF) model. The RF model showed good performance for estimating yields of all three crops with correlation coefficient (r) higher than 0.75 and normalized root means square errors (nRMSE) lower than 18.0%. Our results also showed that crop yields can be satisfactorily forecasted at one to three months prior to harvest. The optimum lead time for yield forecasting depended on crop types. In addition, we found the major predictors influencing crop yield varied between crops. In general, solar radiation and vegetation indices (especially during jointing to milk development stages) were identified as the main predictor for winter wheat;vegetation indices (throughout the growing season) and drought (especially during emergence to tasseling stages) were the most important predictors for spring maize;soil moisture (throughout the growing season) was the dominant predictor for summer maize, late rice, and mid rice;precipitation (especially during booting to heading stages) was the main predictor for early rice. Our study provides insights into practical crop yield forecasting and the understanding of yield response to environmental conditions at a large scale across China. The methods undertaken in this research can be easily implemented in other countries with available information on climate, soil, and vegetation conditions. [ABSTRACT FROM AUTHOR] Copyright of Agricultural & Forest Meteorology is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

9.
Chemical Engineering Journal ; : 131902, 2021.
Article in English | ScienceDirect | ID: covidwho-1363115

ABSTRACT

Developing green and highly efficient water disinfection technique is of great importance to public health. Herein, a near-infrared (NIR) light-triggerable thermo-sensitive defective molybdenum oxide-nitrogen doped carbon (MoO3-x/NCNs) composite was fabricated and applied to water disinfection. With the synergy of photodynamic and photothermal effects, the MoO3-x/NCNs achieve a rapid and effective inactivation of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) as compared to photocatalytic treatment or thermal catalytic alone. Particularly, MONC-3 with optimal ratio can completely inactivate 7.6 log of E. coli and S. aureus within 60 min and 100 min, respectively. The MONC-3 hybrid exhibits efficient charge separation and migration ability due to the formation of Schottky heterojunction, resulting in the highly enhanced ·O2– (11.34×10-10 M) generation activity. Meanwhile, excellent NIR light absorption and photothermal conversion efficiency (52.6%) of MONC-3 can generate local high temperature to promote photocatalytic reaction rate and destruct the bacterial integrity. The monitoring of cell damage process confirmed the irreversible death of bacteria. Based on density functional theory (DFT) calculation, the antibacterial mechanism and Schottky effect were clarified. This work provides new insights for constructing a water disinfection strategy based on plasma-induced photothermal synergy catalysis.

10.
Nanomaterials (Basel) ; 11(4)2021 Mar 31.
Article in English | MEDLINE | ID: covidwho-1158912

ABSTRACT

Vitamin D deficiency is a global issue which has been exacerbated by the COVID-19 pandemic-related lockdowns. Fortification of food staples with vitamin D provides a solution to alleviate this problem. This research explored the use of pea protein nanoemulsion (PPN) to improve the stability of vitamin D in various food products. PPN was created using a pH-shifting and ultrasonication combined method. The physicochemical properties were studied, including particle size, foaming ability, water holding capacity, antioxidant activity, and total phenolic contents. The fortification of several food formulations (non-fat cow milk, canned orange juice, orange juice powder, banana milk, and infant formula) with vitamin D-PPN was investigated and compared to raw untreated pea protein (UPP) regarding their color, viscosity, moisture content, chemical composition, vitamin D stability, antioxidant activity, and morphology. Finally, a sensory evaluation (quantitative descriptive analysis, and consumer testing) was conducted. The results show that PPN with a size of 21.8 nm protected the vitamin D in all tested products. PPN may serve as a potential carrier and stabilizer of vitamin D in food products with minimum effects on the taste and color. Hence, PPN may serve as a green and safe method for food fortification during the COVID-19 pandemic.

11.
China Economic Review ; : 101607, 2021.
Article in English | ScienceDirect | ID: covidwho-1103778

ABSTRACT

This paper examines the short-term and mid-term impact of COVID-19 restrictions on SMEs, based on two waves of phone interviews with a previously surveyed large SME sample in China. The outbreak of COVID-19 and the resultant lockdowns took a heavy toll on SMEs. Afflicted by problems of logistics blocks, labor shortages, and drops in demand, 80% of SMEs were temporarily closed at the time of the first wave of interviews in February 2020. After reining in COVID-19, authorities largely eased lockdown restrictions in April. Consequently, most SMEs had reopened by the time of the second round of surveys in May. However, many firms, particularly export firms, were running at partial capacity, primarily due to inadequate demand. Moreover, around 19% of incorporated enterprises and 25% of self-employed businesses had permanently closed between the two waves of surveys.

13.
Front Med (Lausanne) ; 7: 576275, 2020.
Article in English | MEDLINE | ID: covidwho-1004682

ABSTRACT

We evaluated the impact of the COVID-19 pandemic on anti-VEGF treatment in ophthalmology patients in a single hospital in northern China. A total of 93 anti-VEGF injections were administered to 85 eyes of 72 patients at The China Medical University First Hospital Department of Ophthalmology during the COVID-19 pandemic. Compared to the same period in 2019, the number of injections decreased by 70%. Fifty-nine eyes of 46 patients were receiving 3+PRN anti-VEGF treatment prior to the outbreak of the COVID-19 pandemic; all of these patients experienced treatment interruptions due to COVID-19-associated reasons. Anatomic and functional outcomes suggest that patients with anti-VEGF treatment interruptions are at risk for severe adverse visual sequelae. Moreover, deferred anti-VEGF treatment due to patient-related or department-related reasons during the COVID-19 pandemic may result in poor visual outcomes for new patients. Our results suggest that COVID-19 has had a significant negative effect on anti-VEGF treatment in ophthalmology patients. Detailed guidance from global experts in ophthalmology is highly sought after in these challenging circumstances.

18.
Jpn J Radiol ; 38(5): 409-410, 2020 May.
Article in English | MEDLINE | ID: covidwho-34990

ABSTRACT

The definite diagnosis of corona virus disease 2019 (COVID-19) is based on the viral isolation or positive result of polymerase chain reaction (PCR) from sputum, or nasal swab, or throat swab. However, the sensitivity to detect COVID-19 of real time (RT)-PCR is reported to be lower than that of chest CT. We report a case of 34-year-old man who was diagnosed as negative for COVID-19 based on the four sequential RT-PCR tests of his pharyngeal swab. Chest CT showed patchy ground-glass opacity on admission, and it rapidly progressed to segmental mixed consolidation and ground-glass opacity 3 days after admission, and it resolved in left upper lobe, but showed multifocal ground-glass opacities 7 days after admission, and they resolved within 2 weeks. The fifth RT-PCR test finally revealed positive results at the fifth day after admission. It is difficult to distinguish COVID-19 pneumonia from other viral pneumonia on CT findings alone; however, we emphasize the utility of chest CT to detect early change of COVID-19 in cases which RT-PCR tests show negative results.


Subject(s)
Betacoronavirus/isolation & purification , Coronavirus Infections/diagnostic imaging , Coronavirus Infections/virology , Pneumonia, Viral/diagnostic imaging , Pneumonia, Viral/virology , Adult , Betacoronavirus/genetics , COVID-19 , COVID-19 Testing , COVID-19 Vaccines , Clinical Laboratory Techniques , Coronavirus Infections/diagnosis , Coronavirus Infections/epidemiology , Humans , Male , Pandemics , Pneumonia, Viral/epidemiology , Reverse Transcriptase Polymerase Chain Reaction/methods , SARS-CoV-2 , Tomography, X-Ray Computed/methods
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