ABSTRACT
Spin defects in hexagonal boron nitride (hBN) are promising quantum systems for the design of flexible two-dimensional quantum sensing platforms. Here we rely on hBN crystals isotopically enriched with either 10B or 11B to investigate the isotope-dependent properties of a spin defect featuring a broadband photoluminescence signal in the near infrared. By analyzing the hyperfine structure of the spin defect while changing the boron isotope, we first confirm that it corresponds to the negatively charged boron-vacancy center ([Formula: see text]). We then show that its spin coherence properties are slightly improved in 10B-enriched samples. This is supported by numerical simulations employing cluster correlation expansion methods, which reveal the importance of the hyperfine Fermi contact term for calculating the coherence time of point defects in hBN. Using cross-relaxation spectroscopy, we finally identify dark electron spin impurities as an additional source of decoherence. This work provides new insights into the properties of [Formula: see text] spin defects, which are valuable for the future development of hBN-based quantum sensing foils.
ABSTRACT
Circulating cell-free DNA (cfDNA) is one of the fastest growing and most exciting areas in oncology in recent years. Its potential clinical uses cover now each phase of cancer patient management care (predictive information, detection of the minimal residual disease, early detection of resistance, treatment monitoring, recurrence surveillance, and cancer early detection/screening). This review relates the recent advances in the application of circulating DNA or RNA in oncology building on unpublished or initial findings/work presented at the 10th international symposium on circulating nucleic acids in plasma and serum held in Montpellier from the 20th to the 22nd of September 2017. This year, presenters revealed their latest data and crucial observations notably in relation to (i) the circulating cell-free (cfDNA) structure and implications regarding their optimal detection; (ii) their role in the metastatic or immunological processes; (iii) evaluation of miRNA panels for cancer patient follow up; (iv) the detection of the minimal residual disease; (v) the evaluation of a screening tests for cancer using cfDNA analysis; and (vi) elements of preanalytical guidelines. This work reviews the recent progresses in the field brought to light in the meeting, as well as in the most important reports from the literature, past and present. It proposes a broader picture of the basic research and its potential, and of the implementation and current challenges in the use of circulating nucleic acids in oncology.
