Arthroscopic treatment of an intra-articular hemangioma in the posterior compartment of the knee

AbstractWe report the case of a 37-year-old patient presenting with knee pain and recurrent effusion without instability due to an intra-articular hemangioma in the posterior compartment of the knee. MRI showed features suggesting a diagnosis of hemangioma. Arthroscopic excision of the tumor was performed and the diagnosis was confirmed histologically. There was no recurrence after 5 years of follow-up

Properties of a microjoule-class fiber oscillator mode-locked with a SESAM

Energy scaling of ultrafast Yb-doped fiber oscillators has experienced rapid progress largely driven by many applications that require high average power femtosecond pulses. The fundamental challenge for ultrafast fiber lasers relies on the control of excessive nonlinearity, which limits pulse energy. The development of all-normal dispersion laser cavities based on large-mode-area photonic crystal fibers (PCFs) has enabled significant energy scaling [1-3]. In particular, up to microjoule energy levels have been achieved from rod-type fiber-based oscillators [2-3]. In such lasers, pulse shaping is dominated by the strength of the mode-locking mechanism which determines the pulse properties. In this contribution, we report the generation of high-energy sub-picosecond pulses from a highly normal dispersion fiber laser featuring an Yb-doped rod-type PCF and a large-mode-area PCF [Fig.1(a)]. Passive mode-locking is achieved using saturable absorber mirrors (SAMs). We study the influence of the SAM parameters on performances obtained in this new class of fiber oscillators. The structures exhibit 20 % modulation depths and 500 fs relaxation time with resonant and antiresonant designs. The antiresonant SAM structures ensure absorption bandwidths 45 nm while the resonant structures exhibit 20 nm bandwidths. Stable mode locking with average powers as high as 15 μW at 15 MHz repetition rate, corresponding to microjoule energy level are obtained with all the structures. However, pulse properties and pulse shaping mechanism distinguish between resonant and antiresonant designs. Using a broadband antiresonant SAM leads to generation of highly-chirped pulses with 30 ps duration and 10 nm spectral width [Fig.1(b)]. The output pulses are extra-cavity dechirped down to 550 fs duration. By increasing the strength of the mode-locking mechanism through the combination of the SAM with the NPE process, we obtain shorter pulses with slightly boarder spectra. Indeed, the output pulse duration is decreased from 30 ps to 13 ps by adjusting the wave-plates settings. The dechirped pulse duration is then shortened to 450 fs. We note that the current laser performances are limited to 1 J by the available pump power. Using a resonant SAM structure, the output pulse duration is decreased to 7 ps [Fig.1(b)]. This pulse shortening results from the spectral filtering induced by the limited SAM bandwidth. All these results are in good agreement with numerical simulations which will be discussed in this communication. © 2011 IEEE

Femtosecond microjoule-Class ytterbium fiber lasers

We report the generation of 830 nJ energy from a mode-locked all-normal dispersion fiber laser featuring large-mode-area photonic crystal fibers. After external compression, 550 fs pulses with 1.2 MW peak power are demonstrated. © 2011 OSA

High-energy femtosecond photonic crystal fiber laser

We report the generation of high-energy high-peak power pulses in an all-normal dispersion fiber laser featuring large-mode-area photonic crystal fibers. The self-starting chirped-pulse fiber oscillator delivers 11 W of average power at 15:5 MHz repetition rate, resulting in 710 nJ of pulse energy. The output pulses are dechirped outside the cavity from 7 ps to nearly transform-limited duration of 300 fs, leading to pulse peak powers as high as 1:9 MW. Numerical simulations reveal that pulse shaping is dominated by the amplitude modulation and spectral filtering provided by a resonant semiconductor saturable absorber. © 2010 Optical Society of America

Sub-picosecond microjoule-class fiber lasers

We study the impact of the mode-locking mechanism on the performances of a microjoule-class all-normal dispersion fiber laser featuring large-mode-area photonic crystal fibers. © 2011 OSA

Efficient Microwave-Assisted Solvent Free Synthesis of N-Subtituted Aldimines.

International audienc

Isolated anterior interosseous nerve deficit due to a false aneurysm of the humeral artery: An unusual complication of penetrating arm injury. Case report and literature review

SummaryAnterior interosseous nerve (AIN) injuries account for only 1% of all the nerve injuries at the upper limb. We report the case of a 22-year-old male who sustained a penetrating injury to the arm. No neurological deficit was found at the initial evaluation. However, 6weeks later, he had a motor deficit confined to the territory of the AIN with weakness of the flexor pollicis longus and flexor digitorum longus to the index. He also reported paraesthesia. Tinel's test was positive over the pinpoint wound in the arm, where a painful swelling was felt. Electroneurophysiological testing indicated a deficit of the AIN. Surgical exploration identified a thrombosed false aneurysm of the humeral artery responsible for compression of the median nerve. One month later, the patient had achieved a full recovery. Immediate routine exploration of deep penetrating wounds, although mandatory, may fail to detect any lesions. Close monitoring must be provided subsequently, as gradual nerve compression can result in delayed neurological deficits