Evaluation of individual and ensemble probabilistic forecasts of COVID-19 mortality in the US

Short-term probabilistic forecasts of the trajectory of the COVID-19 pandemic in the United States have served as a visible and important communication channel between the scientific modeling community and both the general public and decision-makers. Forecasting models provide specific, quantitative, and evaluable predictions that inform short-term decisions such as healthcare staffing needs, school closures, and allocation of medical supplies. Starting in April 2020, the US COVID-19 Forecast Hub (https://covid19forecasthub.org/) collected, disseminated, and synthesized tens of millions of specific predictions from more than 90 different academic, industry, and independent research groups. A multi-model ensemble forecast that combined predictions from dozens of different research groups every week provided the most consistently accurate probabilistic forecasts of incident deaths due to COVID-19 at the state and national level from April 2020 through October 2021. The performance of 27 individual models that submitted complete forecasts of COVID-19 deaths consistently throughout this year showed high variability in forecast skill across time, geospatial units, and forecast horizons. Two-thirds of the models evaluated showed better accuracy than a naive baseline model. Forecast accuracy degraded as models made predictions further into the future, with probabilistic error at a 20-week horizon 3-5 times larger than when predicting at a 1-week horizon. This project underscores the role that collaboration and active coordination between governmental public health agencies, academic modeling teams, and industry partners can play in developing modern modeling capabilities to support local, state, and federal response to outbreaks. Significance StatementThis paper compares the probabilistic accuracy of short-term forecasts of reported deaths due to COVID-19 during the first year and a half of the pandemic in the US. Results show high variation in accuracy between and within stand-alone models, and more consistent accuracy from an ensemble model that combined forecasts from all eligible models. This demonstrates that an ensemble model provided a reliable and comparatively accurate means of forecasting deaths during the COVID-19 pandemic that exceeded the performance of all of the models that contributed to it. This work strengthens the evidence base for synthesizing multiple models to support public health action.

Effect of Sancao prescription extracts on lung adencarcinoma cell line(A549) / 中成药

AIM: To investigate the ethanolic and aqueous extracts from Sancao prescription (Spica prunellae, Oldenlandia diffuse (willd) Roxb, Herba agrimoniae) on the proliferation of human lung adenocarcinoma cell line (A549). METHODS: 95% ,60% and 30% ethanolic extract and aqueous extract were prepared from Sancao pre-scription. The MTT assay was used to determine the inhibitory action against the proliferation of A549. RESULTS: IC_(50) of 60% ethanolic extract over A549 was one of the lowest in extracts. Combination of 60% and 90% ethanolic extract showed the synergistic antitumour activity. CONCLUSION: Ethanolic extract of Sancao prescription has and effect on human hung adenocarcinoma(A549).

Research on variation regularity of five main flavonoids contents in Epimedium and processed Epimedium / 中国中药杂志

<p><b>OBJECTIVE</b>To research on the variation regularity of the five main flavonoids contents in Epimedium and processed Epimedium.</p><p><b>METHOD</b>The contents of Epimedin A, Epimedin B, Epimedin C, Icariin and Baohuoside I in Epimedium and processed Epimedium were determined, respectively.</p><p><b>RESULT</b>There were varieties in the contents of Epimedin A, Epimedin B, Epimedin C, Icariin and Baohuoside in Epimedium and processed Epimedium. There were different variety tendencies in different species and different batches.</p><p><b>CONCLUSION</b>The variety tendencies of the contents of five main flavonoids depend on the processing technology and the flavonoids proportion in Epimedium and processed Epimedium.</p>

Determination of Anticancer Activity Components of Flavonoids from Hedyotis diffusa by HPLC / 中国药房

OBJECTIVE:To establish the method for the simultaneous determination of anticancer activity components of flavonoids from Hedyotis diffusa,i.e. quercetin,kaempferol. METHODS:HPLC was applied to determine the contents and performed on Alltima C18(250 mm?4.6 mm,5 ?m) column. Mobile phase consisted of methanol(A)-0.5% glacial acetic acid,(gradient elution). The detection wavelength was aet at 350 nm. RESULTS:The linear range of quercetin was 0.006 2～0.244 0 ?g(r=0.999 8)and that of kaempferol 0.007 8～0.310 6 ?g(r=0.999 9). The average recovery of quercetin was 101.84%(RSD=1.79%,n=6) and that of kaempferol 99.04%(RSD=2.90%,n=6). CONCLUSIONS:The method is simple,accurate and reproducible for the quality control of H. diffusa.