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The article offers information on Direct visualization of electromagnetic wave dynamics by laser-free ultrafast electron microscopy. It mentions Integrating femtosecond lasers with electron microscopies has enabled direct imaging of transient structures and morphologies of materials in real time and space and the development of a laser-free ultrafast electron microscopy (UEM) offering the same capability but without requiring femtosecond lasers and intricate instrumental modifications.

Background: Tension-free end-to-end digital nerve repair or reconstruction under loupe or microscope magnification are surgical treatment options for lacerated digital nerves in patients with multiple injured digits, injuries to the border digits, or injuries to the thumb, with the goal of improved or restored sensation and a decreased risk of painful traumatic neuroma formation. Different techniques for primary repair have been described and include epineurial sutures, nerve "glues" including fibrin-based gels 1,2 , biologic or synthetic absorbable or nonabsorbable nerve wraps or conduits, or a combination of these materials. Nerve "glues" have demonstrated decreased initial gapping at the repair site 3 and an increased tensile load to failure when utilized with a nerve wrap or conduit 4,5 . When there is a gap or defect in the nerve and primary repair is not feasible, nerve allograft and autograft provide similar results and are both better options than conduit reconstruction 6 . Concomitant or isolated digital vascular injuries may also be surgically treated with end-to-end repair in a dysvascular digit, with the goal of digit and function preservation. In the absence of complete circumferential injury or complete amputation, redundant or collateral flow may be present. Single digital artery injuries often do not need to be repaired because of the collateral flow from the other digital artery., Description: Digital nerve and vascular injuries are often found in the context of traumatic wounds. In such cases, surgical exploration is often required, with possible surgical extension of the wounds to facilitate identification of the neurovascular bundles. The proximal and distal ends of the transected nerve and/or artery are identified, and the traumatized ends are incised sharply, maintaining as much length as possible to facilitate end-to-end repair, interposition of a graft, and the use of a conduit. The proximal and distal aspects of the nerve and/or artery are appropriately mobilized by dissecting or releasing any scar tissue or soft tissue that may be tethering the structure. The defect is measured in the natural resting position of the digit. Gentle flexion of the digit may be performed to facilitate a primary repair in the setting of very small defects. Primary repair or reconstruction is selected, and an 8-0 or 9-0 nonabsorbable monofilament suture is utilized to anastomose the appropriate structures under magnification with use of a single or double stitch 6 . A tubular nerve conduit is placed prior to epineurial suturing, or a nerve conduit wrap is applied circumferentially around the repair site and augmented with a fibrin glue. The wound is then irrigated and closed in a standard fashion, as determined by the presence of any soft-tissue or structural injury., Alternatives: Alternatives to primary repair include the use of conduits or autologous or allogenic grafting. Factors that necessitate reconstruction include gapping and poor soft-tissue integrity, which can be related to the mechanism of injury. Alternatives to repair or reconstruction include treatment of the-soft tissue or structural injury without concomitant repair or reconstruction of the damaged digital nerves or vessels., Rationale: Primary end-to-end repair and reconstruction of digital nerves increases a patient's likelihood of sensation recovery, and arterial repair can preserve a digit and avoid the need for amputation. Sensation in the digits is very important for fine motor skills and interaction with the environment, and it is particularly important for patients who rely on their hands for work and/or recreation. For these reasons, the digital nerves to the border digits, such as the ulnar aspect of the small finger, radial aspect of the index finger, and both digital nerves to the thumb, are given particular attention., Expected Outcomes: Surgical intervention to repair or reconstruct the digital nerves increases the likelihood of recovering pre-injury sensation; however, the chance of complete recovery remains low. A systematic review of the outcomes of digital nerve repair in adults published in 2019 showed that the average percentage of patients who had undergone repair and reported a recovery to Highet grade 4 was 24% (range, 6% to 60%) 8 . The rate of adverse events was comparable between the operatively and nonoperatively treated patients, with complications including neuromas, hyperesthesia, and infection., Important Tips: The use of a microvascular background material can provide better visualization of the proximal and distal ends while performing the repair.It is important to sharply guillotine the ends of the nerve to freshen up the laceration and provide healthy nerve ends for repair.Repair sutures need to be passed through the epineurium, with care taken not to pass through the nerve fascicles., Acronyms and Abbreviations: OR = operating roomPIP = proximal interphalangealPT = prothrombin timePTT = partial thromboplastin time., Competing Interests: Disclosure: The Disclosure of Potential Conflicts of Interest forms are provided with the online version of the article (http://links.lww.com/JBJSEST/A461)., (Written work prepared by employees of the Federal Government as part of their official duties is, under the United States Copyright Act, a ‘work of the United States Government’ for which copyright protection under that Act is not available. As such, copyright protection does not extend to the contributions of employees of the Federal Government prepared as part of their employment.)

Objective: The aim of this study was to summarize the prognosis of recurrent infratentorial ependymomas based on treatment and molecular characterization., Methods: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, the authors searched the PubMed, Scopus, Embase, and Ovid databases for studies on recurrent infratentorial ependymomas in patients younger than 25 years of age. Exclusion criteria included case series of fewer than 5 patients and studies that did not provide time-dependent survival data., Results: The authors' database search yielded 482 unique articles, of which 18 were included in the final analysis. There were 479 recurrent infratentorial pediatric ependymomas reported; 53.4% were WHO grade II and 46.6% were WHO grade III tumors. The overall mortality for recurrent infratentorial pediatric ependymomas was 49.1% (226/460). The pooled mean survival was 30.2 months after recurrence (95% CI 22.4-38.0 months). Gross-total resection (GTR) was achieved in 243 (59.0%) patients at initial presentation. The mean survival postrecurrence for those who received initial GTR was 42.3 months (95% CI 35.7-47.6 months) versus 26.0 months (95% CI 9.6-44.6 months) for those who received subtotal resection (STR) (p = 0.032). There was no difference in the mean survival between patients who received GTR (49.3 months, 95% CI 32.3-66.3 months) versus those who received STR (41.4 months, 95% CI 11.6-71.2 months) for their recurrent tumor (p = 0.610). In the studies that included molecular classification data, there were 169 (83.3%) posterior fossa group A (PFA) tumors and 34 (16.7%) posterior fossa group B (PFB) tumors, with 28 tumors harboring a 1q gain. PFA tumors demonstrated worse mean postprogression patient survival (24.7 months, 95% CI 15.3-34.0 months) compared with PFB tumors (48.0 months, 95% CI 32.8-63.2 months) (p = 0.0073). The average postrecurrence survival for patients with 1q+ tumors was 14.7 months., Conclusions: The overall mortality rate for recurrent infratentorial ependymomas was found to be 49.1%, with a pooled mean survival of 30.2 months in the included sample population. More than 80% of recurrent infratentorial ependymomas were of the PFA molecular subtype, and both PFA tumors and those with 1q gain demonstrated worse prognosis after recurrence.

Magnetocrystalline anisotropy (MCA) is one of the key parameters investigated in spin-based electronics (spintronics), e.g. for memory applications. Here, we employ first-principles calculations to study MCA in thin film full Heusler alloy Co 2 CrAl. This material was studied in the past, and has been reported to exhibit half-metallic electronic structure in bulk geometry. In our recent work, we showed that it retains a 100% spin-polarization in thin-film geometry, at CrAl atomic surface termination. Here, we show that the same termination results in a perpendicular magnetic anisotropy, while Co surface termination not only destroys the half-metallicity, but also results in in-plane magnetization orientation. In addition, for films thicker than around 20 nm the contribution from magnetic shape anisotropy may become decisive, resulting in in-plane magnetization orientation. To the best of our knowledge, this is one of the first reports of half-metallic thin-film surfaces with perpendicular magnetic anisotropy. This result may be of interest for potential nano-device applications, and may stimulate a further experimental study of this and similar materials.