Biomedical Journal Style 4 Panel Patient Cohort Multimodal Biomarker Workflow Academic Figure

3:2 aspect ratio (1536 x 1024 pixels), landscape orientation, high-resolution academic research figure in generic biomedical journal publication style, soft muted scientific color palette, minimal elegant design, solid white background, no watermarks, no fake logos, no decorative clutter
Centered top figure title in clean sans-serif academic font: "Patient cohort and multimodal biomarker workflow"
Evenly spaced 4-panel layout with small bold sans-serif A-D labels in the top-left corner of each panel, ample white margins between panels:
Panel A: CONSORT-style patient cohort flow diagram, thin black directional arrows, pale sand fill for all boxes, clear legible black text: linear flow "Screened n=1,248" -> "Eligible n=612" -> splits into two parallel output boxes "Training cohort n=428" and "External validation n=184"; three small side exclusion boxes connected via angled arrows to the main flow path, labeled "missing imaging n=81", "insufficient follow-up n=43", "quality-control fail n=32"
Panel B: Multimodal sample-processing flow, simple minimal line icons left to right with matching small text labels: "CT imaging" scan icon, "blood proteomics" vial icon, "EHR timeline" linear timeline icon, "outcome labels" tag icon, all connected via thin black arrows pointing right into a pale dusty blue fusion box labeled "feature harmonization"
Panel C: Clean minimal Kaplan-Meier survival plot, thin light gray axes, subtle low-opacity light gray gridlines, two smooth distinct curves: muted teal curve labeled "low-risk", soft coral rose curve labeled "high-risk"; x-axis labeled "Months", y-axis labeled "Event-free survival", all text in small legible sans-serif
Panel D: Compact clean table-style performance summary, thin light gray border lines, pale sand subtle fill for cell backgrounds, 3 rows labeled "AUROC", "C-index", "Calibration slope", 2 columns labeled "Internal" / "External"
Style rules enforced: only muted color palette (muted teal, dusty blue, soft coral, pale sand, no neon colors), all lines 1pt thickness maximum, all labels 8-10pt standard academic sans-serif font, precise clean arrows, no dark backgrounds, no extra decorative elements, aligned to clean biomedical research figure formatting guidelines