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Free-electron lasers generate high-brilliance coherent radiation at wavelengths spanning from the infrared to the X-ray domains. The recent development of short-wavelength seeded free-electron lasers now allows for unprecedented levels of control on longitudinal coherence, opening new scientific avenues such as ultra-fast dynamics on complex systems and X-ray nonlinear optics. Although those devices rely on state-of-the-art large-scale accelerators, advancements on laser-plasma accelerators, which harness gigavolt-per-centimetre accelerating fields, showcase a promising technology as compact drivers for free-electron lasers. Using such footprint-reduced accelerators, exponential amplification of a shot-noise type of radiation in a self-amplified spontaneous emission configuration was recently achieved. However, employing this compact approach for the delivery of temporally coherent pulses in a controlled manner has remained a major challenge. Here we present the experimental demonstration of a laser-plasma accelerator-driven free-electron laser in a seeded configuration, where control over the radiation wavelength is accomplished. Furthermore, the appearance of interference fringes, resulting from the interaction between the phase-locked emitted radiation and the seed, confirms longitudinal coherence. Building on our scientific achievements, we anticipate a navigable pathway to extreme-ultraviolet wavelengths, paving the way towards smaller-scale free-electron lasers, unique tools for a multitude of applications in industry, laboratories and universities.

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IMPORTANCE Debate continues about the cause of midfacial growth disturbance in patients with facial clefts. OBJECTIVE To evaluate the functional effect of surgical closure of the lip before palatal closure according to the technique by Delaire on early maxillary growth in patients with complete unilateral cleft lip and palate. DESIGN, SETTING, AND PARTICIPANTS Twenty-two patients with unilateral cleft lip and palate were studied using plaster casts obtained at the time of cheilorhinoplasty and 6 months later before palatal closure. The interrupted lateral muscles were anatomically repositioned using the surgical technique by Delaire. No patients had received preoperative orthodontic treatment or a passive palatal plate. Cast analyses were performed using a digital caliper. MAIN OUTCOMES AND MEASURES Landmark positioning was performed 3 times by 2 different examiners to define intraobserver and interobserver differences. The final maxilla dimensions were recorded as the distances between the mean landmark positions. Using the t test, dimensions obtained before palatal closure were compared with dimensions obtained before lip closure. RESULTS The method allowed good reproducibility. Functional closure of the lip significantly narrowed the transverse anterior cleft areas by −2.36 mm (P < .05). Sagittal variables were increased by 1.68 mm on the nonaffected side and by 1.48 mm on the affected side (P < .05 for both). CONCLUSIONS AND RELEVANCE Functional closure according to the technique by Delaire narrows the transverse dimensions of the maxilla, while simultaneously preserving initial sagittal growth. LEVEL OF EVIDENCE 4.

The aim of this study was to determine the overall complication rate associated with the use of diathermocoagulation in cutting mode for flap dissection.

A Nd:glass laser based on a novel design delivers up to 120 J energy pulses with a quasi-flat-top spatial profile at a 0.1 Hz repetition rate. The laser output is frequency-doubled with 50% efficiency and used to pump Ti:sapphire amplifiers. The developed design is perspective for use in the currently contemplated next step in ultra-high-intensity laser development.