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1.
Med Phys ; 50(5): 3210-3222, 2023 May.
Article in English | MEDLINE | ID: covidwho-2244151

ABSTRACT

BACKGROUND: Semi-supervised learning (SSL) can effectively use information from unlabeled data to improve model performance, which has great significance in medical imaging tasks. Pseudo-labeling is a classical SSL method that uses a model to predict unlabeled samples and selects the prediction with the highest confidence level as the pseudo-labels and then uses the generated pseudo-labels to train the model. Most of the current pseudo-label-based SSL algorithms use predefined fixed thresholds for all classes to select unlabeled data. PURPOSE: However, data imbalance is a common problem in medical image tasks, where the use of fixed threshold to generate pseudo-labels ignores different classes of learning status and learning difficulties. The aim of this study is to develop an algorithm to solve this problem. METHODS: In this work, we propose Multi-Curriculum Pseudo-Labeling (MCPL), which evaluates the learning status of the model for each class at each epoch and automatically adjusts the thresholds for each class. We apply MCPL to FixMatch and propose a new SSL framework for medical image classification, which we call the improved algorithm FaxMatch. To mitigate the impact of incorrect pseudo-labels on the model, we use label smoothing (LS) strategy to generate soft labels (SL) for pseudo-labels. RESULTS: We have conducted extensive experiments to evaluate our method on two public benchmark medical image classification datasets: the ISIC 2018 skin lesion analysis and COVID-CT datasets. Experimental results show that our method outperforms fully supervised baseline, which uses only labeled data to train the model. Moreover, our method also outperforms other state-of-the-art methods. CONCLUSIONS: We propose MCPL and construct a semi-supervised medical image classification framework to reduce the reliance of the model on a large number of labeled images and reduce the manual workload of labeling medical image data.


Subject(s)
COVID-19 , Humans , Curriculum , Algorithms , Benchmarking , Supervised Machine Learning
2.
Sustainability ; 14(9):4874, 2022.
Article in English | MDPI | ID: covidwho-1792440

ABSTRACT

In this paper, an evolutionary game model for the development of panic buying events in COVID-19 is constructed by studying the dynamic process of the public and the government adjusting their strategic choices and playing a continuous game. This paper uses regret theory to depict the public's perceived value of the items in the panic buying situation, describes the characteristics of each stage of the rumors spreading process and the evolution process of panic buying events, and introduces the variable of public critical ability to measure the public's panic buying willingness. The results show that the government's intervention measures according to the characteristics of different stages can effectively control the continuous fermentation time and influence the scope of panic buying events. The implementation of the government's rumor-refutation strategy will also significantly affect the volume of public panic buying, which will help the government timely understand the public's epidemic prevention needs in COVID-19, relieve public panic, and provide a basis for the effective management and scheduling of emergency supplies.

3.
Front Pharmacol ; 11: 614024, 2020.
Article in English | MEDLINE | ID: covidwho-1542362

ABSTRACT

Sepsis-induced myocardial dysfunction is a major contributor to the poor outcomes of septic shock. As an add-on with conventional sepsis management for over 15 years, the effect of Xuebijing injection (XBJ) on the sepsis-induced myocardial dysfunction was not well understood. The material basis of Xuebijing injection (XBJ) in managing infections and infection-related complications remains to be defined. A murine cecal ligation and puncture (CLP) model and cardiomyocytes in vitro culture were adopted to study the influence of XBJ on infection-induced cardiac dysfunction. XBJ significantly improved the survival of septic-mice and rescued cardiac dysfunction in vivo. RNA-seq revealed XBJ attenuated the expression of proinflammatory cytokines and related signalings in the heart which was further confirmed on the mRNA and protein levels. Xuebijing also protected cardiomyocytes from LPS-induced mitochondrial calcium ion overload and reduced the LPS-induced ROS production in cardiomyocytes. The therapeutic effect of XBJ was mediated by the combination of paeoniflorin and hydroxysafflor yellow A (HSYA) (C0127-2). C0127-2 improved the survival of septic mice, protected their cardiac function and cardiomyocytes while balancing gene expression in cytokine-storm-related signalings, such as TNF-α and NF-κB. In summary, Paeoniflorin and HSYA are key active compounds in XBJ for managing sepsis, protecting cardiac function, and controlling inflammation in the cardiac tissue partially by limiting the production of IL-6, IL-1ß, and CXCL2.

4.
Food Control ; : 108372, 2021.
Article in English | ScienceDirect | ID: covidwho-1284090

ABSTRACT

The trend today leans towards urbanization and large farming enterprises. However, in 2019–2020, with the impact of the COVID-19 pandemic, the supply of commercial milk was disrupted, and the local smallholder dairy farmers played an important role in stabilizing nutritional security in rural, arid areas of China. The aim of this study was to describe and understand the operation of smallholder dairy farms and suggest what improvements are needed. We interviewed 45 smallholder dairy farmers from Gansu Province. A questionnaire was used to collect information on the dairy operation, including, number of cows, cow breeds, feed offered, yield and on management and open-ended discussions on the needs of the farmers to improve their dairies. Feed samples were collected at each farm to determine composition and milk samples were collected to analyze for composition and fatty acid content, and to compare the quality with commercial milk. Smallholder farmers generally fed dairy cows local, low-quality forages, mainly wheat straw and corn stover (CS/WS), and the milk yield was low, however, milk had a high content of beneficial unsaturated and polyunsaturated fatty acids. Milk from smallholder farms had lower concentrations of undesirable saturated fatty acids, higher concentrations of beneficial unsaturated and polyunsaturated fatty acids, and a lower atherogenic index than commercial milk. Proper sanitation measures and veterinary care were often lacking in these remote areas, leading to high somatic cell counts (SCC). A modified version of grounded theory was used to construct categories of what the farmers perceived was needed to improve their dairies. Four categories emerged in the following order: 1) equipment and management, 2) government support, 3) better cows, and 4) better feed. In a follow-up survey in 2020 of 18 farmers, conditions generally remained the same, including feed offered the animals, which would indicate that the milk composition remained the same. It was concluded that smallholder dairy farmers can provide nutritional security, especially for local residents in remote, rural, arid areas, but improvements in facilities, management, feed, cow breeds and sanitation are needed. Government subsidies should be implemented to help the smallholder dairy farmers. Results from this study provide information for local governments in their decision-making policies to stabilize smallholder dairies.

5.
Front Med ; 15(3): 486-494, 2021 Jun.
Article in English | MEDLINE | ID: covidwho-1122810

ABSTRACT

Tocilizumab has been reported to attenuate the "cytokine storm" in COVID-19 patients. We attempted to verify the effectiveness and safety of tocilizumab therapy in COVID-19 and identify patients most likely to benefit from this treatment. We conducted a randomized, controlled, open-label multicenter trial among COVID-19 patients. The patients were randomly assigned in a 1:1 ratio to receive either tocilizumab in addition to standard care or standard care alone. The cure rate, changes of oxygen saturation and interference, and inflammation biomarkers were observed. Thirty-three patients were randomized to the tocilizumab group, and 32 patients to the control group. The cure rate in the tocilizumab group was higher than that in the control group, but the difference was not statistically significant (94.12% vs. 87.10%, rate difference 95% CI-7.19%-21.23%, P = 0.4133). The improvement in hypoxia for the tocilizumab group was higher from day 4 onward and statistically significant from day 12 (P = 0.0359). In moderate disease patients with bilateral pulmonary lesions, the hypoxia ameliorated earlier after tocilizumab treatment, and less patients (1/12, 8.33%) needed an increase of inhaled oxygen concentration compared with the controls (4/6, 66.67%; rate difference 95% CI-99.17% to-17.50%, P = 0.0217). No severe adverse events occurred. More mild temporary adverse events were recorded in tocilizumab recipients (20/34, 58.82%) than the controls (4/31, 12.90%). Tocilizumab can improve hypoxia without unacceptable side effect profile and significant influences on the time virus load becomes negative. For patients with bilateral pulmonary lesions and elevated IL-6 levels, tocilizumab could be recommended to improve outcome.


Subject(s)
COVID-19 Drug Treatment , Antibodies, Monoclonal, Humanized , Humans , SARS-CoV-2 , Treatment Outcome
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