Time-resolved X-ray crystallography experiments were first performed in the 1980s, yet they remained a niche technique for decades. With the recent advent of X-ray free electron laser (XFEL) sources and serial crystallographic techniques, time-resolved crystallography has received renewed interest and has become more accessible to a wider user base. Despite this, time-resolved structures represent < 1 % of models deposited in the world-wide Protein Data Bank, indicating that the tools and techniques currently available require further development before such experiments can become truly routine. In this chapter, we demonstrate how applying data multiplexing to time-resolved crystallography can enhance the achievable time resolution at moderately intense monochromatic X-ray sources, ranging from synchrotrons to bench-top sources. We discuss the principles of multiplexing, where this technique may be advantageous, potential pitfalls, and experimental design considerations.
PURPOSE: The time structures of proton spot delivery in proton pencil beam scanning (PBS) radiation therapy are essential in many clinical applications. This study aims to characterize the time structures of proton PBS delivered by both synchrotron and synchrocyclotron accelerators using a non-invasive technique based on scattered particle tracking. METHODS: A pixelated semiconductor detector, AdvaPIX-Timepix3, with a temporal resolution of 1.56 ns, was employed to measure time of arrival of secondary particles generated by a proton beam. The detector was placed laterally to the high-flux area of the beam in order to allow for single particle detection and not interfere with the treatment. The detector recorded counts of radiation events, their deposited energy and the timestamp associated with the single events. Individual recorded events and their temporal characteristics were used to analyze beam time structures, including energy layer switch time, magnet switch time, spot switch time, and the scanning speeds in the x and y directions. All the measurements were repeated 30 times on three dates, reducing statistical uncertainty. RESULTS: The uncertainty of the measured energy layer switch times, magnet switch time, and the spot switch time were all within 1% of average values. The scanning speeds uncertainties were within 1.5% and are more precise than previously reported results. The measurements also revealed continuous sub-milliseconds proton spills at a low dose rate for the synchrotron accelerator and radiofrequency pulses at 7 μs and 1 ms repetition time for the synchrocyclotron accelerator. CONCLUSION: The AdvaPIX-Timepix3 detector can be used to directly measure and monitor time structures on microseconds scale of the PBS proton beam delivery. This method yielded results with high precision and is completely independent of the machine log files.
- MeSH
- časové faktory MeSH
- částice - urychlovače * přístrojové vybavení MeSH
- celková dávka radioterapie * MeSH
- lidé MeSH
- nádory radioterapie MeSH
- plánování radioterapie pomocí počítače * metody MeSH
- polovodiče * MeSH
- protonová terapie * přístrojové vybavení MeSH
- protony MeSH
- synchrotrony přístrojové vybavení MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
A novel approach to the remote-control system for the compact multi-crystal energy-dispersive spectrometer for X-ray emission spectroscopy (XES) applications has been developed. This new approach is based on asynchronous communication between software components and on reactive design principles. In this paper, the challenges faced, their solutions, as well as the implementation and future development prospects are identified. The main motivation of this work was the development of a new holistic communication protocol that can be implemented to control various hardware components allowing both independent operation and easy integration into different SCADA systems.
- MeSH
- software * MeSH
- spektrometrie rentgenová emisní MeSH
- synchrotrony * MeSH
- Publikační typ
- časopisecké články MeSH
The development of nanomedicines for the treatment of neurodegenerative disorders demands innovative nanoarchitectures for combined loading of multiple neuroprotective compounds. We report dual-drug loaded monoolein-based liquid crystalline architectures designed for the encapsulation of a therapeutic protein and a small molecule antioxidant. Catalase (CAT) is chosen as a metalloprotein, which provides enzymatic defense against oxidative stress caused by reactive oxygen species (ROS) such as hydrogen peroxide (H2O2). Curcumin (CU), solubilized in fish oil, is co-encapsulated as a chosen drug with multiple therapeutic activities, which may favor neuro-regeneration. The prepared self-assembled biomolecular nanoarchitectures are characterized by biological synchrotron small-angle X-ray scattering (BioSAXS) at multiple compositions of the lipid/co-lipid/water phase diagram. Constant fractions of curcumin (an antioxidant) and a PEGylated agent (TPEG1000) are included with regard to the lipid fraction. Stable cubosome architectures are obtained for several ratios of the lipid ingredients monoolein (MO) and fish oil (FO). The impact of catalase on the structural organization of the cubosome nanocarriers is revealed by the variations of the cubic lattice parameters deduced by BioSAXS. The outcome of the cellular uptake of the dual drug-loaded nanocarriers is assessed by performing a bioassay of catalase peroxidatic activity in lysates of nanoparticle-treated differentiated SH-SY5Y human cells. The obtained results reveal the neuroprotective potential of the in vitro studied cubosomes in terms of enhanced peroxidatic activity of the catalase enzyme, which enables the inhibition of H2O2 accumulation in degenerating neuronal cells.
- MeSH
- kapalné krystaly chemie MeSH
- katalasa chemie MeSH
- kurkumin chemie MeSH
- lidé MeSH
- maloúhlový rozptyl MeSH
- nanostruktury chemie MeSH
- peroxid vodíku chemie MeSH
- polyethylenglykoly chemie MeSH
- reaktivní formy kyslíku MeSH
- synchrotrony MeSH
- zobrazování trojrozměrné MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
One of the greatest enigmas of modern biology is how the geometry of muscular and skeletal structures are created and how their development is controlled during growth and regeneration. Scaling and shaping of vertebrate muscles and skeletal elements has always been enigmatic and required an advanced technical level in order to analyse the cell distribution in 3D. In this work, synchrotron X-ray computed microtomography (µCT) and chemical contrasting has been exploited for a quantitative analysis of the 3D-cell distribution in tissues of a developing salamander (Pleurodeles waltl) limb - a key model organism for vertebrate regeneration studies. We mapped the limb muscles, their size and shape as well as the number and density of cells within the extracellular matrix of the developing cartilage. By using tomographic approach, we explored the polarity of the cells in 3D, in relation to the structure of developing joints. We found that the polarity of chondrocytes correlates with the planes in joint surfaces and also changes along the length of the cartilaginous elements. Our approach generates data for the precise computer simulations of muscle-skeletal regeneration using cell dynamics models, which is necessary for the understanding how anisotropic growth results in the precise shapes of skeletal structures.
Nothosaurs form a subclade of the secondarily marine Sauropterygia that was well represented in late Early to early Late Triassic marine ecosystems. Here we present and discuss the internal skull anatomy of the small piscivorous nothosaur Nothosaurus marchicus from coastal to shallow marine Lower Muschelkalk deposits (Anisian) of Winterswijk, The Netherlands, which represents the oldest sauropterygian endocast visualized to date. The cranial endocast is only partially encapsulated by ossified braincase elements. Cranial flattening and lateral constriction by hypertrophied temporal musculature grant the brain a straight, tubular geometry that lacks particularly well-developed cerebral lobes but does potentially involve distinguishable optic lobes, suggesting vision may have represented an important sense during life. Despite large orbit size, the circuitous muscular pathway linking the basisphenoidal and orbital regions indicates poor oculomotor performance. This suggests a rather fixed ocular orientation, although eye placement and neck manoeuvrability could have enabled binocular if not stereoscopic vision. The proportionally large dorsal projection of the braincase endocast towards the well-developed pineal foramen advocates substantial dependence on the corresponding pineal system in vivo. Structures corroborating keen olfactory or acoustic senses were not identified. The likely atrophied vomeronasal organ argues against the presence of a forked tongue in Nothosaurus, and the relative positioning of external and internal nares contrasts respiratory configurations proposed for pistosauroid sauropterygians. The antorbital domain furthermore accommodates a putative rostral sensory plexus and pronounced lateral nasal glands that were likely exapted as salt glands. Previously proposed nothosaurian 'foramina eustachii' arose from architectural constraints on braincase development rather than representing functional foramina. Several modifications to brain shape and accessory organs were achieved through heterochronic development of the cranium, particularly the braincase. In summary, the cranium of Nothosaurus marchicus reflects important physiological and neurosensory adaptations that enabled the group's explosive invasion of shallow marine habitats in the late Early Triassic.
Terrestrial isopods moult first the posterior and then the anterior half of the body, allowing for storage and recycling of CaCO3. We used synchrotron-radiation microtomography to estimate mineral content within skeletal segments in sequential moulting stages of Porcellio scaber. The results suggest that all examined cuticular segments contribute to storage and recycling, however, to varying extents. The mineral within the hepatopancreas after moult suggests an uptake of mineral from the ingested exuviae. The total maximum loss of mineral was 46% for the anterior and 43% for the posterior cuticle. The time course of resorption of mineral and mineralisation of the new cuticle suggests storage and recycling of mineral in the posterior and anterior cuticle. The mineral in the anterior pereiopods decreases by 25% only. P. scaber has long legs and can run fast; therefore, a less mineralised and thus lightweight cuticle in pereiopods likely serves to lower energy consumption during escape behaviour. Differential demineralisation occurs in the head cuticle, in which the cornea of the complex eyes remains completely mineralised. The partes incisivae of the mandibles are mineralised before the old cuticle is demineralised and shed. Probably, this enables the animal to ingest the old exuviae after each half moult.
- MeSH
- fyziologická kalcifikace MeSH
- hepatopankreas fyziologie MeSH
- hlava fyziologie MeSH
- hmyzí proteiny fyziologie MeSH
- Isopoda fyziologie MeSH
- minerály chemie MeSH
- počítačová simulace MeSH
- počítačové zpracování obrazu MeSH
- rentgenová mikrotomografie MeSH
- rohovka fyziologie MeSH
- shazování tělního pokryvu MeSH
- synchrotrony MeSH
- uhličitan vápenatý chemie MeSH
- ústa fyziologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
This paper discusses an intercomparison campaign performed in the mixed radiation field at the CERN-EU (CERF) reference field facility. Various instruments were employed: conventional and extended-range rem counters including a novel instrument called LUPIN, a bubble detector using an active counting system (ABC 1260) and two tissue-equivalent proportional counters (TEPCs). The results show that the extended range instruments agree well within their uncertainties and within 1σ with the H*(10) FLUKA value. The conventional rem counters are in good agreement within their uncertainties and underestimate H*(10) as measured by the extended range instruments and as predicted by FLUKA. The TEPCs slightly overestimate the FLUKA value but they are anyhow consistent with it when taking the comparatively large total uncertainties into account, and indicate that the non-neutron part of the stray field accounts for ∼30 % of the total H*(10).
- MeSH
- dávka záření * MeSH
- design vybavení MeSH
- Evropská unie MeSH
- kalibrace MeSH
- monitorování radiace přístrojové vybavení metody MeSH
- neutrony MeSH
- protony MeSH
- radiační ochrana přístrojové vybavení metody MeSH
- synchrotrony MeSH
- vystavení vlivu životního prostředí analýza MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
The outcomes from the feasibility study on utilization of synchrotron radiation X-ray microtomography (SR-μCT) to investigate the texture and the quantitative mineralogical composition of selected calcium oxalate-based urinary calculi fragments are presented. The comparison of the results obtained by SR-μCT analysis with those derived from current standard analytical approaches is provided. SR-μCT is proved as a potential effective technique for determination of texture, 3D microstructure, and composition of kidney stones.
- MeSH
- krystalizace MeSH
- lidé středního věku MeSH
- lidé MeSH
- močové kameny chemie MeSH
- rentgenová mikrotomografie MeSH
- studie proveditelnosti MeSH
- synchrotrony MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- MeSH
- částice - urychlovače klasifikace využití MeSH
- cyklotrony ekonomika využití MeSH
- lidé MeSH
- onkologická péče - zařízení trendy využití zásobování a distribuce MeSH
- radiační onkologie metody přístrojové vybavení trendy MeSH
- radioterapie metody přístrojové vybavení využití MeSH
- synchrotrony ekonomika využití MeSH
- zařízení a zdroje radiace MeSH
- Check Tag
- lidé MeSH
