Time-Frequency Signatures of Electronic Coherence of Colloidal CdSe Quantum Dot Dimer Assemblies Probed at Room Temperature by Two-Dimensional Electronic Spectroscopy.

Electronic coherence signatures can be directly identified in the time-frequency maps measured in two-dimensional electronic spectroscopy (2DES). Here, we demonstrate the theory and discuss the advantages of this approach via the detailed application to the fast-femtosecond beatings of a wide variety of electronic coherences in ensemble dimers of quantum dots (QDs), assembled from QDs of 3 nm in diameter, with 8% size dispersion in diameter. The observed and computed results can be consistently characterized directly in the time-frequency domain by probing the polarization in the 2DES setup. The experimental and computed time-frequency maps are found in very good agreement, and several electronic coherences are characterized at room temperature in solution, before the extensive dephasing due to the size dispersion begins. As compared to the frequency-frequency maps that are commonly used in 2DES, the time-frequency maps allow exploiting electronic coherences without additional post-processing and with fewer 2DES measurements. Towards quantum technology applications, we also report on the modeling of the time-frequency photocurrent response of these electronic coherences, which paves the way to integrating QD devices with classical architectures, thereby enhancing the quantum advantage of such technologies for parallel information processing at room temperature.

Transamniotic stem cell therapy (TRASCET) mitigates bowel damage in a model of gastroschisis.

PURPOSE: We sought to determine whether intraamniotic delivery of concentrated amniotic-derived mesenchymal stem cells (afMSCs) could reduce damage to exposed bowel in experimental gastroschisis. METHODS: Rat fetuses (n=117) with surgically created gastroschisis were divided into three groups: untreated animals (n=62) and two groups receiving volume-matched intraamniotic injections of either saline (n=25) or 2 × 10(6) cells/mL of syngeneic, labeled afMSCs (n=30). Animals were killed before term, along with normal controls (NL). Blinded observers performed computerized measurements of total and segmental (serosa, muscularis, and mucosa) intestinal wall thicknesses. Statistical comparisons were by ANOVA (P<0.05). RESULTS: Among survivors with gastroschisis, there were statistically significant decreases in total bowel wall, serosal, muscular, and mucosal thicknesses in the afMSC group vs. the untreated group (P=0.001/0.035/0.001/0.005, respectively) and vs. the saline group (P=0.003/0.05/<0.001/0.026, respectively). There were no such significant differences between the untreated and saline groups. There were no differences between the afMSC group and NL, except for a significantly thicker muscular layer in the afMSC group (P=0.014). Labeled afMSCs were scarcely identified, suggesting a paracrine effect. CONCLUSIONS: Amniotic mesenchymal stem cells mitigate bowel damage in experimental gastroschisis after concentrated intraamniotic injection. Transamniotic stem cell therapy (TRASCET) may become a practical component of the treatment of gastroschisis.