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Remote Sensing for Agriculture, Ecosystems, and Hydrology Xxii ; 11528, 2020.
Article in English | Web of Science | ID: covidwho-1242187


Fast and reliable tests for the new coronavirus are urgently needed. Current Polymerase Chain Reaction based virus detection approaches are typically time-consuming and expensive. Technologies capable of providing a fast, real-time and non-contact detection of virus contamination and real-time virus classification are not yet available. Here, we demonstrate the potential of a fluorescence detection technique along with machine-learning based classification for virus detection. The ultraviolet (UV) light irradiated virus emits a fluorescent signal with a characteristic spectrum, which is regarded as a fingerprint for the virus. We analyzed eight virus samples including a heat-inactivated SARS-CoV-2 (virus causing COVID-19) and collected a number of emission spectra. Machine learning techniques are applied to discriminate among the candidate viruses via classifying a number of spectra data collected. First, Principle Component Analysis (PCA) was applied to reduce spectra data dimensionality. Then support vector machine (SVM) with various kernel functions (kernel-SVM), k-nearest-neighbor (k-NN) and Artificial Neural Networks (ANN) methods were used to classify these viruses with dimension-reduced data from PCA. We found that dimension-reduced data in 3 principal components (PCs) space performs better than that in 2 PCs space in the machine learning algorithms mentioned above. Variance ratio analysis is able to explain nearly 95% of variance which allows nearly 100% accuracy of predictions for 25% data test set randomly chosen from the whole dataset. Finally, cross validation (CV) analysis is applied to kernel-SVM and k-NN methods.

Zhonghua Xin Xue Guan Bing Za Zhi ; 48(6): 472-476, 2020 Jun 24.
Article in Chinese | MEDLINE | ID: covidwho-683960


Objective: To evaluate the efficacy and safety of fibrinolysis strategy in patients with acute ST-segment elevation myocardial infarction (STEMI) during the COVID-19 epidemic, and to provide reference value for optimization of fibrinolytic process on the premise of prevention and control of COVID-19 transmission, including self-protection of medical staff. Methods: The efficacy and safety of fibrinolysis were retrospectively analyzed in 7 patients with acute STEM, who hospitalized from February 29, 2020 to April 3, 2020 in the Department of Cardiology, Wuhan Union Hospital of Tongji Medical College, Huazhong University of Science and Technology. To optimize the fibrinolytic process on the premise of prevention and control of COVID-19 transmission, including self-protection of medical staff, a full-time medical team in charge of fibrinolysis under third-grade protection was established. The acute STEMI patients were treated immediately in a fixed and isolated area in emergency department before receiving green channel fibrinolysis. Blood samples for complete blood count, COVID-19 antibody test and nasopharyngeal swab samples for COVID-19 nucleic acid test were made before fibrinolysis, while the chest CT examination was accomplished after fibrinolysis. By comparing differences of time from the first electrocardiogram (ECG) to fibrinolysis before and after the improvement of fibrinolytic process, the effect of optimization of the fibrinolytic process was evaluated. Results: In the present study, seven patients with acute STEMI received fibrinolysis therapy, 6 of them achieved reperfusion and no bleeding was observed in all of the patients. Five out of the 7 patients were hospitalized after fibrinolysis, and the hospitalization days were 19.6 days on average. By following up to April 14, 2020, none of the 7 patients died. The first 2 patients were treated according to the routine medical procedure and the time from the first ECG to fibrinolysis were 201 and 106 minutes, respectively. After the optimization of the fibrinolytic process, the time from the first ECG to fibrinolysis of the last 5 patients were 42, 46, 51, 43 and 54 minutes, respectively,which was significantly shorter than that before optimization. Conclusions: During the COVID-19 epidemic, fibrinolysis in patients with acute STEMI is safe, effective and easy to implement. Therefore, it is recommended as the top priority for the patients with acute STEMI with indications for fibrinolysis. On the premise of prevention and control of COVID-19 transmission, including self-protection of medical staff, the duration of myocardial ischemia can be shortened by optimization of the fibrinolytic process.

Betacoronavirus , Coronavirus Infections , Fibrinolytic Agents/therapeutic use , Pandemics , Pneumonia, Viral , ST Elevation Myocardial Infarction , COVID-19 , Coronavirus Infections/epidemiology , Epidemics , Humans , Pneumonia, Viral/epidemiology , Retrospective Studies , SARS-CoV-2 , ST Elevation Myocardial Infarction/drug therapy , Thrombolytic Therapy , Time Factors , Treatment Outcome