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Radio-frequency (RF) accelerators providing high-quality relativistic electron beams are an important resource enabling many areas of science, as well as industrial and medical applications. Two decades ago, laser-plasma accelerators 1 that support orders of magnitude higher electric fields than those provided by modern RF cavities produced quasi-monoenergetic electron beams for the first time 2 , 3 – 4 . Since then, high-brightness electron beams at gigaelectronvolt (GeV) beam energy and competitive beam properties have been demonstrated from only centimetre-long plasmas 5 , 6 , 7 , 8 – 9 , a substantial advantage over the hundreds of metres required by RF-cavity-based accelerators. However, despite the considerable progress, the comparably large energy spread and the fluctuation (jitter) in beam energy still effectively prevent laser-plasma accelerators from driving real-world applications. Here we report the generation of a laser-plasma electron beam using active energy compression, resulting in a performance so far only associated with modern RF-based accelerators. Using a magnetic chicane, the electron bunch is first stretched longitudinally to imprint an energy correlation, which is then removed with an active RF cavity. The resulting energy spread and energy jitter are reduced by more than an order of magnitude to below the permille level, meeting the acceptance criteria of a modern synchrotron, thereby opening the path to a compact storage ring injector and other applications. A laser-plasma electron beam generated using active energy compression demonstrates reduction in energy spread and jitter by an order of magnitude to below the permille level, comparable with modern radio-frequency accelerators.

The PETRA IV project will have a storage ring with an ultra-low natural emittance of 20 pm rad. For an off-axis injection scheme with working points at the difference resonance, it is critical to ensure that the vertical excursion caused by transversal coupling does not affect injection efficiency. In this contribution, we present simulation results of an off-axis injection near the coupling resonance, which provides equal equilibrium emittances. The advantages and disadvantages of such a scheme are discussed.

The present state of progress in laser wakefield acceleration encourages considering it as a practical alternative to conventional particle accelerators. A promising application would be to use a laser-plasma accelerator as an injector for a synchrotron light source. Yet, the energy spread and jitter of the laser-plasma beam pose a significant difficulty for an efficient injection. In this paper, we propose a design of a prototype injector to deliver 500 MeV low-intensity electron bunches to the DESY-II electron synchrotron. The design utilizes presently available conventional accelerator technology, such as a chicane and an X-band radio frequency cavity, to reduce the energy spread and jitter of the electron beam down to a sub-per-mille level.

Biodegradation of natural silk scaffolds made from gauze and satin fabrics was studied both in vitro and in vivo. Experiments were conducted using phosphate-buffered saline (PBS) and Fenton’s reagent to model degradation. Samples demonstrated high stability in the model of physiological conditions and varying degradation rates in oxidative stress. In vivo studies in rats showed good biocompatibility of the scaffolds and a gradual reduction in inflammatory responses. The findings highlight the potential of silk scaffolds for use in various areas of regenerative medicine.

We present a 3D study of nanostructural features of a bioprinted tissue spheroid interacting with polyurethane dual-scale biocompatible scaffold manufactured by three-dimensional printing and electrospinning. Three-dimensional analysis of fibroblasts interacting with electrospun polyurethane fibers was conducted using scanning probe nanotomography with an experimental setup combining ultramicrotome and a scanning probe microscope. Three-dimensional reconstruction demonstrates direct visualization of cell membrane protrusions and coherent cell-fiber interfaces, the formation of which is a prerequisite for an efficient tissue engineered implant. Analysis of obtained 3D data allows for quantitative calculation of the important morphological parameters of adhered cells, scaffolds, and cell-scaffold interfaces. The proposed method may be successfully applied to investigate 3D cell-scaffold constructs at nanoscale.

Despite decades of research, the goal of achieving scarless wound healing remains elusive. One of the approaches, treatment with polymeric microcarriers, was shown to promote tissue regeneration in various models of wound healing. The effects of such an approach are attributed to transferred cells with polymeric microparticles functioning merely as inert scaffolds. We aimed to establish a bioactive biopolymer carrier that would promote would healing and inhibit scar formation in the murine model of deep skin wounds. Here we characterize two candidate types of microparticles based on fibroin/gelatin or spidroin and show that both types increase re-epithelialization rate and inhibit scar formation during skin wound healing. Interestingly, the effects of these microparticles on inflammatory gene expression and cytokine production by macrophages, fibroblasts, and keratinocytes are distinct. Both types of microparticles, as well as their soluble derivatives, fibroin and spidroin, significantly reduced the expression of profibrotic factors and in mouse embryonic fibroblasts. However, only fibroin/gelatin microparticles induced transient inflammatory gene expression and cytokine production leading to an influx of inflammatory Ly6C+ myeloid cells to the injection site. The ability of microparticle carriers of equal proregenerative potential to induce inflammatory response may allow their subsequent adaptation to treatment of wounds with different bioburden and fibrotic content.

Traumatic brain injury is one of the leading causes of disability among the working-age population worldwide. Despite attempts to develop neuroprotective therapeutic approaches, including pharmacological or cellular technologies, significant advances in brain regeneration have not yet been achieved. Development of silk fibroin-based biomaterials represents a new frontier in neuroregenerative therapies after brain injury. In this study, we estimated the short and long-term effects of silk fibroin scaffold transplantation on traumatic brain injury and biocompatibility of this biomaterial within rat neuro-vascular cells. Silk fibroin microparticles were injected into a brain damage area 1 day after the injury. Silk fibroin affords neuroprotection as judged by diminished brain damage and recovery of long-term neurological functions. We did not detect considerable toxicity to neuro-vascular cells cultured on fibroin/fibroin-gelatin microparticles in vitro. Cultivation of primary cell cultures of neurons and astrocytes on silk fibroin matrices demonstrated their higher viability under oxygen-glucose deprivation compared to 2D conditions on plastic plates. Thus, we conclude that scaffolds based on silk fibroin can become the basis for the creation of constructs aimed to treat brain regeneration after injury.

Nanoscale morphological features of branched processes of glial cells may be of decisive importance for neuron–astrocyte interactions in health and disease. The paper presents the results of a correlation analysis of images of thin processes of astrocytes in nervous tissue of the mouse brain, which were obtained by scanning probe microscopy (SPM) and transmission electron microscopy (TEM) with high spatial resolution. Samples were prepared and imaged using a unique hardware combination of ultramicrotomy and SPM. Astrocyte details with a thickness of several tens of nanometers were identifiable in the images, making it possible to reconstruct the three-dimensional structure of astrocytic processes by integrating a series of sequential images of ultrathin sections of nervous tissue in the future.

The effect of recombinant spidroin (RS) hydrogel (HG) on anterior epithelial cells and keratocytes of the human cornea was studied in vitro. Corneal injuries are highly prevalent in developing countries according to the World Health Organization. Various technologies have recently been proposed to restore the damaged surface of the cornea. Use of biodegradable silk-based materials, including recombinant analogs of the spider silk protein spidroin, is an important avenue of research in the field of wound healing and corneal regeneration. Spidroins are well known for their optimal balance of strength and elasticity. Given their biological compatibility, lack of immunogenicity, and biodegradability, spidroins provide a biomaterial for tissue engineering and regenerative medicine. HGs based on RS rS2/12-RGDS were therefore tested for cytotoxicity toward isolated corneal epithelial cells and keratocytes with regard to possible changes in cell phenotype and migratory activity. A promising outlook and therapeutic potential were demonstrated for RS-based HGs.

Storage ring commissioning-like simulations are necessary to assess the feasibility of proposed future lattice designs. This paper proposes a python package for commissioning-like simulations based on python accelerator toolbox (pyAT). The software includes: 1) errors definition, 2) correction routines from open trajectory to optics and coupling correction and 3) the evaluation of the relevant parameters, such as dynamic aperture (DA), injection efficiency (IE) and Touschek lifetime (TL). The software is fully exploiting parallel resources (local or on a computing cluster) and is thought to be easily configured for any machine (examples are given for EBS DBA and HMBA, for PETRA IV and for FCC-ee). Whenever possible analytic formulas are made available to the user. Several examples are detailed in this paper and included in the code as demonstrations of use.