Spatial light modulators have become an essential tool for advanced microscopy, enabling breakthroughs in 3D, phase, and super-resolution imaging. However, continuous spatial-light modulation that is capable of capturing sub-millisecond microscopic motion without diffraction artifacts and polarization dependence is challenging. Here we present a photothermal spatial light modulator (PT-SLM) enabling fast phase imaging for nanoscopic 3D reconstruction. The PT-SLM can generate a step-like wavefront change, free of diffraction artifacts, with a high transmittance and a modulation efficiency independent of light polarization. We achieve a phase-shift > π and a response time as short as 70 µs with a theoretical limit in the sub microsecond range. We used the PT-SLM to perform quantitative phase imaging of sub-diffractional species to decipher the 3D nanoscopic displacement of microtubules and study the trajectory of a diffusive microtubule-associated protein, providing insights into the mechanism of protein navigation through a complex microtubule network.

• MeSH
• Time Factors MeSH
• Microscopy, Interference methods   statistics & numerical data   MeSH
• Metal Nanoparticles ultrastructure   MeSH
• Humans MeSH
• Microscopy, Atomic Force MeSH
• Microscopy, Phase-Contrast methods   statistics & numerical data   MeSH
• Microtubules metabolism   ultrastructure   MeSH
• Nanotechnology MeSH
• Nanotubes ultrastructure   MeSH
• Optical Phenomena MeSH
• Computer Simulation MeSH
• Microtubule-Associated Proteins metabolism   MeSH
• Cell Cycle Proteins metabolism   MeSH
• Schizosaccharomyces pombe Proteins metabolism   MeSH
• Light MeSH
• Tubulin metabolism   MeSH
• Gold MeSH
• Imaging, Three-Dimensional methods   statistics & numerical data   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

Článek porovnává možnosti měření likvorové dynamiky pomocí tří různých metod magnetické rezonance: metody fázového kontrastu (Phase contrast, PC), sekvence SPAMM (Spatial modulation of magnetization) a sekvence PSIF. Principy všech metod jsou zde stručně objasněny. Jedině PC umožňuje kvantifikovat okamžitou rychlost a průtok. Výhoda sekvence PSIF spočívá v jednoduchosti měření (bez potřeby EKG) a v možnosti zobrazit větší objem zájmu (3D). Jedinou výhodou sekvence SPAMM je možnost dynamického zobrazení toku i v případě turbulentního charakteru, kdy interpretace výsledku v pnpadě PC může být složitá. Mereni byla prováděna jak na skupině zdravých dobrovolníků (10 dospělých, 10 dětí), tak s pacienty (stenóza akveduktu, stav po ventrikulostomii, syringomyelic). V případě syringomyelic byl porov¬ L Časový charakter pulzace uvnitř míšní dutiny s extramedulárním prostorem. U malých dutin (zhruba do 2 cm délky) jsme nenaměřili výraznější pohyb likvoru. U rozměrnějších kavit (mezi 2 až 10 cm) byla délka pulzní likvorové vlny kratší v intramedulámí dutině než v extramedulárním prostoru. U rozsáhlých syringomyelií (více než 10 cm) jsme většinou naměřili shodnou pulzaci uvnitř a vně míchy.

The authors compare the possibilities of assessment of the dynamics of cerebrospinal fiuid (CSF) by three different methods of magnetic resonance: phase contrast (PC), SPAMM sequence (spatial modulation of magnetization) and the PSIF sequence. The principles of all methods are briefly explained. Only PC makes quantification of the rate and flow possible. The advantage of the PSIF sequence is in the simplicity of measurement (not requiring ECG) and the possibility to visualize a larger area of interest (3D). The only advantage of sequence SPAMM is the opportunity of dynamic imaging of the flow even when it is turbulent when the interpretation of results obtained by PC may be complicated. The assessments were made in a group of healthy volunteers (10 adults, 10 children) as well as in patients (stenosis of the aqueduct, condition after ventriculostomy, syringomyelia). In syringomye¬ lia the character of the pulsation in the spinal cavity was compared with the extramedullary space. In small cavities (under 2 cm long) no marked movement of CSF was found. In larger cavities (2 to 10 cm) the lenght of the pulse CSF wave was shorter in the intramedullary cavity than in the extramedullary space. In extensive syringomyelias (more than 10 cm) usually the same pulsation was recorded inside and outside the spinal cord.

• MeSH
• Magnetic Resonance Imaging, Cine methods   MeSH
• Cerebrospinal Fluid MeSH
• Syringomyelia diagnosis   MeSH

• MeSH
• Magnetic Resonance Spectroscopy methods   diagnostic use   MeSH
• Magnetic Resonance Imaging MeSH
• Publication type
• Monograph MeSH

• Conspectus
• Lékařské vědy. Lékařství
• NML Fields
• radiologie, nukleární medicína a zobrazovací metody
• techniky diagnostické zobrazovací

The publication contains the proceedings of a symposium that focused on the development of liver cirrhosis on a molecular and cellular level. Intended for professional public.

• MeSH
• Cell Biology MeSH
• Liver Cirrhosis etiology   MeSH
• Molecular Biology MeSH
• Publication type
• Congress MeSH
• Collected Work MeSH
• News MeSH

• Conspectus
• Patologie. Klinická medicína
• NML Fields
• hepatologie
• molekulární biologie, molekulární medicína

We report the first vibrational circular dichroism (VCD) measurement of spatial heterogeneity in a sample using infrared (IR) microsampling. Vibrational circular dichroism spectra are typically measured using a standard IR cell with an IR beam diameter of 10 mm or greater making it impossible to investigate the spatial heterogeneity of a solid film sample. We have constructed a VCD sampling assembly with either 3 mm or 1 mm spatial resolution. An XY-translation stage was used to measure spectra at different spatial locations producing IR and VCD maps of the sample. In addition, a rotating sample stage was employed using a dual photoelastic modulator (PEM) setup to suppress artifacts due to linear birefringence in solid-phase or film samples. Infrared and VCD mapping of an insulin fibril film has been carried out at both 3 and 1 mm spatial resolution, and lysozyme films were mapped at 1 mm resolution. The IR spectra of different spots vary in intensity due primarily to sample thickness. The changes in the VCD intensity across the map largely correlate to corresponding changes in the IR map. Closer inspection of the insulin map revealed changes in the relative intensities of the VCD spectra not present in the parent IR spectra, which indicated differences in the degree of supramolecular chirality of the fibrils in the various spatial regions. For lysozyme films, in addition to different degrees of supramolecular chirality, reversal of the net fibril chirality was observed. The large signal-to-noise ratio observed at 1 mm resolution implies the feasibility of further increasing the spatial resolution by one or two orders of magnitude for protein fibril film samples.

• MeSH
• Amyloid analysis   chemistry   MeSH
• Artifacts MeSH
• Circular Dichroism methods   MeSH
• Insulin analysis   chemistry   MeSH
• Muramidase analysis   chemistry   MeSH
• Signal Processing, Computer-Assisted MeSH
• Cattle MeSH
• Spectroscopy, Fourier Transform Infrared MeSH
• Vibration MeSH
• Animals MeSH
• Check Tag
• Cattle MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH

BACKGROUND: Hatching is modulated by a combination of intrinsic and extrinsic factors. Annual killifish are adapted to complete their entire life cycle in annually desiccating habitats. Spending most of their life in the embryonic stage, they have evolved adaptations to survive desiccated conditions and match their hatching with the unpredictable onset of the aquatic phase of the pool. We examined spatial and temporal synchrony of hatching in natural populations of four species of African annual killifish (genus Nothobranchius). We compared differences and variability in hatching dates among years, regions, pools, and species and matched them with data on inundations of individual pools. RESULTS: Inundations typically coincided with peak rainfall in early January. We found considerable spatial and temporal synchrony in 1 year, but less synchrony in the other 2 years. Hatching generally occurred 0-20 days after inundation; fish at most sites hatched synchronously (<1 week) but some sites showed protracted hatching or two age cohorts. One species tended to hatch earlier than the other three. CONCLUSIONS: We suggest that hatching of annual killifish in the wild is a result of the interplay between environmental conditions and individual predisposition to respond to threshold environmental cues, ensuring effective bet-hedging against unpredictable inundation. Developmental Dynamics 246:827-837, 2017. © 2017 Wiley Periodicals, Inc.

• MeSH
• Biological Variation, Population * MeSH
• Cyprinodontiformes physiology   MeSH
• Adaptation, Physiological * MeSH
• Reproduction MeSH
• Life Cycle Stages * MeSH
• Environment MeSH
• Animals MeSH
• Check Tag
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

• MeSH
• Lasers MeSH
• Publication type
• Meeting Abstract MeSH
• Collected Work MeSH

• Conspectus
• Optika
• NML Fields
• fyzika, biofyzika
• technika

• MeSH
• Cell Biology MeSH
• Molecular Biology MeSH
• Publication type
• Monograph MeSH

• Conspectus
• Biochemie. Molekulární biologie. Biofyzika
• NML Fields
• biologie
• cytologie, klinická cytologie