Search results for "FAST"
showing 10 items of 821 documents
Longevity: epigenetic and biomolecular aspects
2015
AbstractMany aging theories and their related molecular mechanisms have been proposed. Simple model organisms such as yeasts, worms, fruit flies and others have massively contributed to their clarification, and many genes and pathways have been associated with longevity regulation. Among them, insulin/IGF-1 plays a key and evolutionary conserved role. Interestingly, dietary interventions can modulate this pathway. Calorie restriction (CR), intermittent fasting, and protein and amino acid restriction prolong the lifespan of mammals by IGF-1 regulation. However, some recent findings support the hypothesis that the long-term effects of diet also involve epigenetic mechanisms. In this review, w…
RabbitQC: high-speed scalable quality control for sequencing data
2019
Abstract Motivation Modern sequencing technologies continue to revolutionize many areas of biology and medicine. Since the generated datasets are error-prone, downstream applications usually require quality control methods to pre-process FASTQ files. However, existing tools for this task are currently not able to fully exploit the capabilities of computing platforms leading to slow runtimes. Results We present RabbitQC, an extremely fast integrated quality control tool for FASTQ files, which can take full advantage of modern hardware. It includes a variety of operations and supports different sequencing technologies (Illumina, Oxford Nanopore and PacBio). RabbitQC achieves speedups between …
Inverse square root level-crossing quantum two-state model
2020
We introduce a new unconditionally solvable level-crossing two-state model given by a constant-amplitude optical field configuration for which the detuning is an inverse-square-root function of time. This is a member of one of the five families of bi-confluent Heun models. We prove that this is the only non-classical exactly solvable field configuration among the bi-confluent Heun classes, solvable in terms of finite sums of the Hermite functions. The general solution of the two-state problem for this model is written in terms of four Hermite functions of a shifted and scaled argument (each of the two fundamental solutions presents an irreducible combination of two Hermite functions). We pr…
Structure development in poly(ethylene terephthalate) quenched from the melt at high cooling rates: X-ray scattering and microhardness study
2000
The structure and microhardness of poly(ethylene terephthalate) (PET) cooled from the melt, using a wide range of cooling rates, was studied. PET thin films rapidly cooled from the melt (cooling rates larger than 5°C/s) show a continuous variation of structure and properties depending on cooling rate. Results highlight differences in the micro-mechanical properties of the glass suggesting the occurrence of amorphous structures with different degrees of internal chain ordering. The comparative X-ray scattering study of two glassy PET samples (7500 and 17°C/s) reveals the occurrence of frozen-in electron density states giving rise to an excess of scattering for the amorphous sample solidified…
Luminescence and transient absorption in ZnWO4 and ZnWO4–Fe crystals
2001
Abstract The transient absorption spectra and relaxation kinetics under pulse electron beam excitation in ZnWO 4 and ZnWO 4 –Fe, as well as luminescence spectra and decay kinetics, were studied. It is shown that a fraction of transient absorption is due to luminescence center excited state. The energy transfer from intrinsic excitations to the defect or impurity states is not efficient. The role of Fe-impurities in the decay process is discussed.
Time-resolved optical absorption in YAlO3 crystals
2004
Abstract The present work is devoted to the investigation of transient absorption (TA) induced by a pulsed electron beam (E=250 keV ) in pure and doped YAlO3 (YAP) single crystals. The nature of centers responsible for TA is discussed.
Determination of the irradiation field at the research reactor TRIGA Mainz for BNCT.
2009
For the application of the BNCT for the excorporal treatment of organs at the TRIGA Mainz, the basic characteristics of the radiation field in the thermal column as beam geometry, neutron and gamma ray energies, angular distributions, neutron flux, as well as absorbed gamma and neutron doses must be determined in a reproducible way. To determine the mixed irradiation field thermoluminescence detectors (TLD) made of CaF(2):Tm with a newly developed energy-compensation filter system and LiF:Mg,Ti materials with different (6)Li concentrations and different thicknesses as well as thin gold foils were used.
Comparison of Single-Echo T2-weighted Fast Spin-Echo and Conventional Spin-Echo MR Sequences
1998
We compared single-echo T2-weighted fast spin-echo (FSE) magnetic resonance imaging and conventional spin-echo (CSE) T2-weighted imaging in the detection of brain lesions of multiple sclerosis (MS). 16 patients with clinically definite MS underwent brain imaging at 0.5 T with T2-weighted single-echo fast spin-echo (FSE) and conventional spin-echo (CSE) sequences. Image analysis was performed by three of the investigators who worked together to reduce interobserver variability. Statistical analysis was performed using Student's t test to assess the difference in the contrast-to-noise (C/N) ratio of MS lesions between CSE and FSE sequences. The Wilcoxon signed rank test was used to evaluate …
Self-trapped exciton in Li2GeO3
1997
Abstract Self-trapped excitons (STE) are discovered in Li2GeO3 crystal. The PL band at 2.7 eV with a strong Stoke's shift is excited in the intrinsic absorption range of Li2GeO3 crystal, in which the optical gap is situated at 6 eV. The activation energy of the STE luminescence thermal quenching is not monoenergetic and is situated in the range 40–100 meV. The luminescence is strongly polarized. The decay kinetics can be characterized by τ = 0.9 ms at 45 K. At 5 K it can be approximated by fast (0.6 ms) and slow (4–2.5 ms) components. Decay kinetics is determined by triplet state of STE splits in zero magnetic field. Two different excited triplet states (centers) have the average ODMR param…
Preferential Type II Muscle Fiber Damage From Plyometric Exercise
2012
Context: Plyometric training has been successfully used in different sporting contexts. Studies that investigated the effect of plyometric training on muscle morphology are limited, and results are controversial with regard to which muscle fiber type is mainly affected. Objective: To analyze the skeletal muscle structural and ultrastructural change induced by an acute bout of plyometric exercise to determine which type of muscle fibers is predominantly damaged. Design: Descriptive laboratory study. Setting: Research laboratory. Patients or Other Participants: Eight healthy, untrained individuals (age = 22 ± 1 years, height = 179.2 ± 6.4 cm, weight = 78.9 ± 5.9 kg). Intervention(s): Partici…