The method of iterative particle reconstruction (IPR), introduced by Wieneke (Meas Sci Technol 24:024008, 2013), constitutes a major step toward Lagrangian particle tracking in densely seeded flows (Schanz et al. in Exp Fluids 57:1–27, 2016). Here we present novel approaches in several key aspects of the algorithm, which, in combination, triple the working range of IPR in terms of particle image densities. The updated method is proven to be fast, accurate and robust against image noise and other imaging artifacts. Most of the proposed changes to the original processing are easy to implement and come at low computational cost. Furthermore, a bundle adjustment scheme that simultaneously updates the 3D locations of all particles and the camera calibrations is introduced. While the particle position optimization proved to be more effective using localized ‘shake’ schemes, this so-called global shake scheme constitutes an effective measure to correct for decalibrations and vibrations, acting as an in-situ single-image volume-self-calibration. Further optimization strategies using such approaches are conceivable. Graphic abstract

Successful immunotherapy of Hodgkin's disease is so far hampered by the striking unresponsiveness of lymphoma infiltrating immune cells. To mobilize both adoptive and innate immune cells for an anti-tumor attack we fused the pro-inflammatory cytokines IL2 and IL12 to an anti-CD30 scFv antibody in a dual cytokine fusion protein to accumulate both cytokines at the malignant CD30+ Hodgkin/Reed-Sternberg cells in the lymphoma lesion. The tumor-targeted IL12-IL2 fusion protein was superior in activating resting T cells to amplify and secrete pro-inflammatory cytokines compared to targeted IL2 or IL12 alone. NK cells were also activated by the dual cytokine protein to secrete IFN-γ and to lyse target cells. The tumor-targeted IL12-IL2, when applied by i.v. injection to immune-competent mice with established antigen-positive tumors, accumulated at the tumor site and induced tumor regression. Data demonstrate that simultaneous targeting of two cytokines in a spatial and temporal simultaneous fashion to pre-defined tissues is feasible by a dual-cytokine antibody fusion protein. In the case of IL12 and IL2, this produced superior anti-tumor efficacy implying the strategy to muster a broader immune cell response in the combat against cancer.

The flow around a surface mounted cube with incoming turbulent or laminar boundary layer has been topic of many experimental and numerical investigations in the past decades. Despite its simple geometry the flow generates a set of complex vortical structures in front and around the cube, includes flow separation at the three front plane edges with corresponding subsequent shear layer dynamics enveloping recirculation zones. Downstream of the cube a large unsteady flow separation region is present which is associated with typical quasi-periodic bluff-body wake dynamics. Therefore the flow configuration is well suited to enhance the understanding of similar unsteady and separated flow phenomena in many aerodynamic and engineering applications. In the present experimental investigation we aim at resolving a large spectrum of spatial and temporal scales in the flow around a cube with incoming laminar and turbulent boundary layers by using the most recent developments of dense 3D Lagrangian particle tracking (LPT) and high resolution TR-PIV for Reynolds numbers based on cube size in the range $$\text {Re}_H = U_\infty \,H\,\nu ^{-1} = 2000 - 8000$$ Re H = U ∞ H ν - 1 = 2000 - 8000 . The results documented in the present paper consist of snapshots and the analysis of long time-series of highly resolved 3D and 2D velocity fields suited to enhance the understanding of coherent structure dynamics and of corresponding statistical Lagrangian and Eulerian flow properties. Premultiplied velocity spectra and 3D pressure distributions are calculated and discussed as well. Finally, the measurement data is compared to results obtained with a simulation based on the lattice Boltzmann method (LBM). Graphic abstract