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Two-dimensional transition metal dichalcogenides, particularly MoS2, are interesting materials for many applications in aerospace research, radiation therapy and bioscience more in general. Since in many of these applications MoS2-based nanomaterials can be placed in an aqueous environment while exposed to ionizing radiation, both experimental and theoretical studies of their behaviour under these conditions is particularly interesting. Here, we study the effects of tiny imparted doses of 511 keV photons to MoS2 nanoflakes in water solution. To the best of our knowledge, this is the first study in which ionizing radiation on 2D-MoS2 occurs in water. Interestingly, we find that, in addition to the direct interaction between high-energy photons and nanoflakes, reactive chemical species, generated by γ-photons induced radiolysis of water, come into play a relevant role. A radiation transport Monte Carlo simulation allowed determining the elements driving the morphological and spectroscopical changes of 2D-MoS2, experimentally monitored by SEM microscopy, DLS, Raman and UV–vis spectroscopy, AFM, and X-ray photoelectron techniques. Our study demonstrates that radiolysis products affect the Molybdenum oxidation state, which is massively changed from the stable + 4 and + 6 states into the rarer and more unstable + 5. These findings will be relevant for radiation-based therapies and diagnostics in patients that are assuming drugs or contrast agents containing 2D-MoS2 and for aerospace biomedical applications of 2DMs investigating their actions into living organisms on space station or satellites. [ABSTRACT FROM AUTHOR]

Background/aim: Neoadjuvant systemic therapy (NAT) in breast cancer can make tumors resectable or reduce the extent of surgery needed for locally advanced cancers. It can also better prevent distant relapse and possibly modulate drug therapy by adjusting adjuvant therapy (AD) based on the response to NAT, either by escalating or de-escalating the treatment. However, clear evidence of improved outcomes is currently missing. Here, we report on breast cancer patients treated with NAT at our institution., Patients and Methods: One hundred twenty-seven patients treated at our Radiation Oncology department between 2004 and 2021 were retrospectively analyzed. All patients had localized or locally advanced breast cancer, were treated with NAT, and received postoperative radiotherapy. The outcomes considered were overall survival (OS), loco-regional recurrence-free survival (LRRFS), and distant metastases-free survival (DMFS). A matched patient population treated with AD during the same period and at the same center was used for comparison., Results: The 5-year predicted OS was 87% in the NAT group and 81.5% in the AD group (p-value=0.179), while LRRFS was 93.2% in the NAT group and 100% in the AD group (p=0.005). The 5-year predicted DMFS was 84.6% in the NAT group and 82.1% in AD patients (p=0.367). In the NAT group, the only prognostic factor significantly related to improved outcomes was the pathological node response, with an OS of 95.6% in patients without residual node disease compared to 75.1% in patients with evidence of residual node disease., Conclusion: Our study, despite the limitations of a small number of patients and its retrospective nature, confirms the data of previous larger studies. In terms of DMFS and OS, NAT is at least as effective as AD. NAT represents a great opportunity for personalized modulation of treatment in node-positive breast cancer patients., (Copyright © 2024 International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)