Search results for "kuvantaminen"
showing 10 items of 59 documents
Viral highway to nucleus exposed by image correlation analyses.
2018
AbstractParvoviral genome translocation from the plasma membrane into the nucleus is a coordinated multistep process mediated by capsid proteins. We used fast confocal microscopy line scan imaging combined with image correlation methods including auto-, pair- and cross-correlation, and number and brightness analysis, to study the parvovirus entry pathway at the single-particle level in living cells. Our results show that the endosome-associated movement of virus particles fluctuates from fast to slow. Fast transit of single cytoplasmic capsids to the nuclear envelope is followed by slow movement of capsids and fast diffusion of capsid fragments in the nucleoplasm. The unique combination of …
Bacteriophage imaging : past, present and future
2018
The visualization of viral particles only became possible after the advent of the electron microscope. The first bacteriophage images were published in 1940 and were soon followed by many other publications that helped to elucidate the structure of the particles and their interaction with the bacterial hosts. As sample preparation improved and new technologies were developed, phage imaging became important approach to morphologically classify these viruses and helped to understand its importance in the biosphere. In this review we discuss the main milestones in phage imaging, how it affected our knowledge on these viruses and recent developments in the field. peerReviewed
Compact Cell Imaging Device (CoCID) provides insights into the cellular origins of viral infections
2021
The overall CoCID concept is centred on providing virologists with a next-generation imaging device, which, through increased penetration and depth of focus, as well as through high natural contrast and sensitivity to organelle density (including virus-related organelles), will produce higher-fidelity ultrastructural images of whole intact cells. These insights will, in turn, help increase our understanding of the links between the structural reorganisation of cells and the mechanisms of viral entry, replication, assembly, and egress in cells. CoCID will provide this valuable imaging capability in the form of a compact lab-scale device that will greatly improve the accessibility of soft X-r…
Picture naming yields highly consistent cortical activation patterns: Test–retest reliability of magnetoencephalography recordings
2020
Reliable paradigms and imaging measures of individual-level brain activity are paramount when reaching from group-level research studies to clinical assessment of individual patients. Magnetoencephalography (MEG) provides a direct, non-invasive measure of cortical processing with high spatiotemporal accuracy, and is thus well suited for assessment of functional brain damage in patients with language difficulties. This MEG study aimed to identify, in a delayed picture naming paradigm, source-localized evoked activity and modulations of cortical oscillations that show high test–retest reliability across measurement days in healthy individuals, demonstrating their applicability in clinical set…
Concepts to Reveal Parvovirus–Nucleus Interactions
2021
Parvoviruses are small single-stranded (ss) DNA viruses, which replicate in the nucleoplasm and affect both the structure and function of the nucleus. The nuclear stage of the parvovirus life cycle starts at the nuclear entry of incoming capsids and culminates in the successful passage of progeny capsids out of the nucleus. In this review, we will present past, current, and future microscopy and biochemical techniques and demonstrate their potential in revealing the dynamics and molecular interactions in the intranuclear processes of parvovirus infection. In particular, a number of advanced techniques will be presented for the detection of infection-induced changes, such as DNA modification…
Hyperspectral imaging of asteroids using an FPI-based sensor
2021
The compositions of asteroids are of interest for the planetary sciences, mining, and planetary defense. The main method for evaluating these compositions is reflectance spectroscopy. Spectroscopic measurements performed from Earth can not resolve how different materials are distributed on the asteroids, making flyby-- and rendezvous missions necessary for obtaining detailed information. Using the CubeSat platform could reduce the costs of these missions, but it also sets constraints on the payload mass and volume. One small and light instrument capable of producing spatially resolved spectral data is a hyperspectral imager based on the Fabry-Perot interferometer. We propose a method of cal…
Laboratory phase‐contrast nanotomography of unstained Bombus terrestris compound eyes
2021
Imaging the visual systems of bumblebees and other pollinating insects may increase understanding of their dependence on specific habitats and how they will be affected by climate change. Current high-resolution imaging methods are either limited to two dimensions (light- and electron microscopy) or have limited access (synchrotron radiation x-ray tomography). For x-ray imaging, heavy metal stains are often used to increase contrast. Here, we present micron-resolution imaging of compound eyes of buff-tailed bumblebees (Bombus terrestris) using a table-top x-ray nanotomography (nano-CT) system. By propagation-based phase-contrast imaging, the use of stains was avoided and the microanatomy co…
Generating Hyperspectral Skin Cancer Imagery using Generative Adversarial Neural Network
2020
In this study we develop a proof of concept of using generative adversarial neural networks in hyperspectral skin cancer imagery production. Generative adversarial neural network is a neural network, where two neural networks compete. The generator tries to produce data that is similar to the measured data, and the discriminator tries to correctly classify the data as fake or real. This is a reinforcement learning model, where both models get reinforcement based on their performance. In the training of the discriminator we use data measured from skin cancer patients. The aim for the study is to develop a generator for augmenting hyperspectral skin cancer imagery. peerReviewed
Bio-imaging with the helium-ion microscope: A review
2021
Scanning helium-ion microscopy (HIM) is an imaging technique with sub-nanometre resolution and is a powerful tool to resolve some of the tiniest structures in biology. In many aspects, the HIM resembles a field-emission scanning electron microscope (FE-SEM), but the use of helium ions rather than electrons provides several advantages, including higher surface sensitivity, larger depth of field, and a straightforward charge-compensating electron flood gun, which enables imaging of non-conductive samples, rendering HIM a promising high-resolution imaging technique for biological samples. Starting with studies focused on medical research, the last decade has seen some particularly spectacular …
Real-space imaging with pattern recognition of a ligand-protected Ag374 nanocluster at sub-molecular resolution
2018
High-resolution real-space imaging of nanoparticle surfaces is desirable for better understanding of surface composition and morphology, molecular interactions at the surface, and nanoparticle chemical functionality in its environment. However, achieving molecular or sub-molecular resolution has proven to be very challenging, due to highly curved nanoparticle surfaces and often insufficient knowledge of the monolayer composition. Here, we demonstrate sub-molecular resolution in scanning tunneling microscopy imaging of thiol monolayer of a 5 nm nanoparticle Ag374 protected by tert-butyl benzene thiol. The experimental data is confirmed by comparisons through a pattern recognition algorithm t…