2 research outputs found
Controlling quantum effects in enhanced strong-field ionisation with machine-learning techniques
We study non-classical pathways and quantum interference in enhanced
ionisation of diatomic molecules in strong laser fields using machine learning
techniques. Quantum interference provides a bridge, which facilitates
intramolecular population transfer. Its frequency is higher than that of the
field, intrinsic to the system and depends on several factors, for instance the
state of the initial wavepacket or the internuclear separation. Using
dimensionality reduction techniques, namely t-distributed stochastic neighbour
embedding (t-SNE) and principal component analysis (PCA), we investigate the
effect of multiple parameters at once and find optimal conditions for enhanced
ionisation in static fields, and controlled ionisation release for two-colour
driving fields. This controlled ionisation manifests itself as a step-like
behaviour in the time-dependent autocorrelation function. We explain the
features encountered with phase-space arguments, and also establish a hierarchy
of parameters for controlling ionisation via phase-space Wigner
quasiprobability flows, such as specific coherent superpositions of states,
electron localisation and internuclear-distance ranges.Comment: 39 pages, 21 figure
A pre-clinical validation plan to evaluate analytical sensitivities of molecular diagnostics such as BD MAX MDR-TB, Xpert MTB/Rif Ultra and FluoroType MTB
Rapid diagnosis of tuberculosis (TB) and antibiotic resistances are imperative to initiate effective treatment and to stop transmission of the disease. A new generation of more sensitive, automated molecular TB diagnostic tests has been recently launched giving microbiologists more choice between several assays with the potential to detect resistance markers for rifampicin and isoniazid. In this study, we determined analytical sensitivities as 95% limits of detection (LoD(95)) for Xpert MTB/Rif Ultra (XP-Ultra) and BD-MAX MDR-TB (BD-MAX) as two representatives of the new test generation, in comparison to the conventional FluoroType MTB (FT-MTB). Test matrices used were physiological saline solution, human and a mucin-based artificial sputum (MUCAS) each spiked with Mycobacterium tuberculosis in declining culture- and qPCR-controlled concentrations. With BD-MAX, XP-Ultra, and FTMTB, we measured LoD(95)(TB) values of 2.1 cfu/ml (CI95%: 0.9-23.3), 3.1 cfu/ml (CI95%: 1.288.9), and 52.1 cfu/ml (CI95%: 16.7-664.4) in human sputum;of 6.3 cfu/ml (CI95%: 2.931.8), 1.5 cfu/ml (CI95%: 0.7-5.0), and 30.4 cfu/ml (CI95%: 17.4-60.7) in MUCAS;and of 2.3 cfu/ml (CI95%: 1.1-12.0), 11.5 cfu/ml (CI95%: 5.6-47.3), and 129.1 cfu/ml (CI95%: 82.8-273.8) in saline solution, respectively. LoD(95) of resistance markers were 9 to 48 times higher compared to LoD(95)(TB). BD-MAX and XP-Ultra have an equal and significantly increased analytical sensitivity compared to conventional tests. MUCAS resembled human sputum, while both yielded significantly different results than normal saline. MUCAS proved to be suitable for quality control of PCR assays for TB diagnostics