The manuscript "Forecasting of PM2.5 concentration based on variational mode decomposition and deep learning," by Yun Cheng and Chao Zhang, was published as a preprint in Scientific Reports on 05 June 2026. Per the manuscript, the authors apply **variational mode decomposition (VMD)** to split PM2.5 time series into intrinsic mode functions, compute sample entropy to measure complexity, and use K-means to cluster components into high-, medium-, and low-frequency bands. They train separate `TCN`-`BiLSTM` forecasting models per band and apply an attention-based weighted fusion to produce final predictions. According to the paper, the approach achieved a lowest RMSE of **16.920 µg/m3**, a lowest MAE of **11.134 µg/m3**, and a highest R² of **0.960** on their evaluation dataset (Scientific Reports, 05 June 2026). Editorial analysis: the paper exemplifies a common hybrid signal-decomposition plus deep-learning pattern for environmental forecasting and will be of practical interest to practitioners building short-term air-quality predictors. The manuscript "Forecasting of PM2.5 concentration based on variational mode decomposition and deep learning," by Yun Cheng and Chao Zhang, was published as a preprint in Scientific Reports on 05 June 2026. Per the manuscript, the authors apply varia... [1653 chars]