64 research outputs found
Mathematical Modelling of Optical Coherence Tomography
In this chapter a general mathematical model of Optical Coherence Tomography
(OCT) is presented on the basis of the electromagnetic theory. OCT produces
high resolution images of the inner structure of biological tissues. Images are
obtained by measuring the time delay and the intensity of the backscattered
light from the sample considering also the coherence properties of light. The
scattering problem is considered for a weakly scattering medium located far
enough from the detector. The inverse problem is to reconstruct the
susceptibility of the medium given the measurements for different positions of
the mirror. Different approaches are addressed depending on the different
assumptions made about the optical properties of the sample. This procedure is
applied to a full field OCT system and an extension to standard (time and
frequency domain) OCT is briefly presented.Comment: 28 pages, 5 figures, book chapte
Antiangiogenic drugs in ovarian cancer
Ovarian cancer continues to be a major cause of morbidity and mortality in women. Antiangiogenic treatments have emerged as a promising strategy to treat ovarian cancer. This article reviews the rationale supporting the use of antiangiogenic treatments in ovarian cancer, the clinical development of this group of drugs and the toxicities specific to this modality of treatment
Broadband Multi-wavelength Properties of M87 during the 2017 Event Horizon Telescope Campaign
In 2017, the Event Horizon Telescope (EHT) Collaboration succeeded in capturing the first direct image of the center of the M87 galaxy. The asymmetric ring morphology and size are consistent with theoretical expectations for a weakly accreting supermassive black hole of mass ∼6.5 × 10^{9} Mo. The EHTC also partnered with several international facilities in space and on the ground, to arrange an extensive, quasi-simultaneous multi-wavelength campaign. This Letter presents the results and analysis of this campaign, as well as the multi-wavelength data as a legacy data repository. We captured M87 in a historically low state, and the core flux dominates over HST-1 at high energies, making it possible to combine core flux constraints with the more spatially precise very long baseline interferometry data. We present the most complete simultaneous multi-wavelength spectrum of the active nucleus to date, and discuss the complexity and caveats of combining data from different spatial scales into one broadband spectrum. We apply two heuristic, isotropic leptonic single-zone models to provide insight into the basic source properties, but conclude that a structured jet is necessary to explain M87's spectrum. We can exclude that the simultaneous γ-ray emission is produced via inverse Compton emission in the same region producing the EHT mm-band emission, and further conclude that the γ-rays can only be produced in the inner jets (inward of HST-1) if there are strongly particle-dominated regions. Direct synchrotron emission from accelerated protons and secondaries cannot yet be excluded
Host choice in a bivoltine bee: how sensory constraints shape innate foraging behaviors
Оценка качества образования на основе компетентностного подхода
В работе представлен практический опыт оценки качества образования в новом формате компетентностного подход
Genetic loci associated with heart rate variability and their effects on cardiac disease risk
Reduced cardiac vagal control reflected in low heart rate variability (HRV) is associated with greater risks for cardiac morbidity and mortality. In two-stage meta-analyses of genome-wide association studies for three HRV traits in up to 53,174 individuals of European ancestry, we detect 17 genome-wide significant SNPs in eight loci. HRV SNPs tag non-synonymous SNPs (in NDUFA11 and KIAA1755), expression quantitative trait loci (eQTLs) (influencing GNG11, RGS6 and NEO1), or are located in genes preferentially expressed in the sinoatrial node (GNG11, RGS6 and HCN4). Genetic risk scores account for 0.9 to 2.6% of the HRV variance. Significant genetic correlation is found for HRV with heart rate (-0.74 < r(g) < -0.55) and blood pressure (-0.35 < r(g) < -0.20). These findings provide clinically relevant biological insight into heritable variation in vagal heart rhythm regulation, with a key role for genetic variants (GNG11, RGS6) that influence G-protein heterotrimer action in GIRK-channel induced pacemaker membrane hyperpolarization
Erratum: Genetic loci associated with heart rate variability and their effects on cardiac disease risk
Correction to article number 15805 published in June 2017 in Nature Communications, vol 8
Erratum: Genetic loci associated with heart rate variability and their effects on cardiac disease risk
Correction to article number 15805 published in June 2017 in Nature Communications, vol 8
Growth hormone secretion pattern is an independent regulator of growth hormone actions in humans
- …