A Prospective Study to Examine Responsiveness and Minimally Important Differences (MIDs) for the CLEFT-Q Scales Following Three Cleft-Specific Operations.

The aim of this study was to examine internal responsiveness and estimate minimally important differences (MIDs) for CLEFT-Q scales.In this prospective cohort study, participants completed the CLEFT-Q appearance and health-related quality of life (HRQL) scales before and six months after cleft-related surgery.Seven cleft centres in Canada, USA and UK participated.Patients were ages 8-29 years with CL/P.Patients underwent rhinoplasty, orthognathic or cleft lip scar revision surgery.Internal responsiveness was examined using Cohen's d effect sizes (ESs) based on the following interpretation: 0.20-0.49 small, 0.50-0.79 moderate and ≥ 0.80 large. MIDs were estimated using two distribution-based approaches.Participants had a rhinoplasty (n = 31), orthognathic (n = 21) or cleft lip scar revision (n = 18) surgery. Most participants were males (56%) and aged 8-11 years (41%). Following rhinoplasty, ESs were larger for the nose (0.92, p = 0.001) and nostrils (0.94, p < 0.001) scales than for the face scale (0.51, p = 0.003). MIDs ranged between 6.2-10.4. For orthognathic surgery, larger ES was observed for the jaws scale (1.80, p < 0.001) compared with the teeth (1.16, p < 0.001), face (1.15, p = 0.001) and lips (0.94, p < 0.001) scales. MIDs ranged between 5.9-14.4. In the cleft lip scar revision sample, the largest ES was observed for the nose scale (0.76, p = 0.03), followed by lips (0.58, p = 0.009) and cleft lip scar (0.50, p = 0.043) scales. MIDs ranged between 6.4-12.3.CLEFT-Q detected change in key outcomes for three cleft-specific surgeries, providing evidence of its responsiveness. Estimated MIDs will aid in interpreting this PROM.

A bright triggered twin-photon source in the solid state.

A non-classical light source emitting pairs of identical photons represents a versatile resource of interdisciplinary importance with applications in quantum optics and quantum biology. To date, photon twins have mostly been generated using parametric downconversion sources, relying on Poissonian number distributions, or atoms, exhibiting low emission rates. Here we propose and experimentally demonstrate the efficient, triggered generation of photon twins using the energy-degenerate biexciton-exciton radiative cascade of a single semiconductor quantum dot. Deterministically integrated within a microlens, this nanostructure emits highly correlated photon pairs, degenerate in energy and polarization, at a rate of up to (234±4) kHz. Furthermore, we verify a significant degree of photon indistinguishability and directly observe twin-photon emission by employing photon-number-resolving detectors, which enables the reconstruction of the emitted photon number distribution. Our work represents an important step towards the realization of efficient sources of twin-photon states on a fully scalable technology platform.

Exploring Dephasing of a Solid-State Quantum Emitter via Time- and Temperature-Dependent Hong-Ou-Mandel Experiments.

We probe the indistinguishability of photons emitted by a semiconductor quantum dot (QD) via time- and temperature-dependent two-photon interference (TPI) experiments. An increase in temporal separation between consecutive photon emission events reveals a decrease in TPI visibility on a nanosecond time scale, theoretically described by a non-Markovian noise process in agreement with fluctuating charge traps in the QD's vicinity. Phonon-induced pure dephasing results in a decrease in TPI visibility from (96±4)% at 10 K to a vanishing visibility at 40 K. In contrast to Michelson-type measurements, our experiments provide direct access to the time-dependent coherence of a quantum emitter on a nanosecond time scale.

Highly indistinguishable photons from deterministic quantum-dot microlenses utilizing three-dimensional in situ electron-beam lithography.

The success of advanced quantum communication relies crucially on non-classical light sources emitting single indistinguishable photons at high flux rates and purity. We report on deterministically fabricated microlenses with single quantum dots inside which fulfil these requirements in a flexible and robust quantum device approach. In our concept we combine cathodoluminescence spectroscopy with advanced in situ three-dimensional electron-beam lithography at cryogenic temperatures to pattern monolithic microlenses precisely aligned to pre-selected single quantum dots above a distributed Bragg reflector. We demonstrate that the resulting deterministic quantum-dot microlenses enhance the photon-extraction efficiency to (23±3)%. Furthermore we prove that such microlenses assure close to pure emission of triggered single photons with a high degree of photon indistinguishability up to (80±7)% at saturation. As a unique feature, both single-photon purity and photon indistinguishability are preserved at high excitation power and pulsed excitation, even above saturation of the quantum emitter.

[Horseshoe kidney stones: benefit of flexible ureterorenoscopy with holmium laser]. / Calculs urinaires et rein en fer à cheval: place de l'urétérorénoscopie souple-laser.

OBJECTIVES: We aim to assess the outcome of the flexible ureterorenoscopy (F-URS) with holmium laser in treating horseshoe kidney (HSK) stones. PATIENTS AND METHODS: We reviewed retrospectively the records of 18 patients with HSK stone (18 renal units) who underwent F-URS using holmium laser from December 2004 to October 2009. The mean age was 37.7±6.9 years. The F-URS used after the extracorporeal shock wave lithotripsy (ESWL) failure in eight patients (44.4%) and four patients (22.2%) had PCNL failure. The follow up visit range were between 4 and 6 weeks with plain radiograph (KUB) and renal ultrasound or non contrast computed tomography scan (NCCT). Success rate was defined as stone free or residual fragment less than 3 mm. Use of auxiliary procedures like ESWL were considered as treatment failure. RESULTS: Eighteen patients, three females and 15 males with mean age was 37.7±6.9 years with HSK calculi underwent ureteroscopic management. The presenting symptoms were renal colic, urinary tract infection or hematuria. We found different HSK stone location (11 mixed calyceal, three mixed pelvic and calyceal and four pelvic). The average stone burden was 15.5±7.3 mm and the mean operative time was 112±9.4 minutes. All over procedures were 27, with mean average of 1.5 procedures per patient. The success rate was 89%. CONCLUSION: The F-URS with holmium laser is an efficient minimal invasive procedure in treating HSK stones.

Ultrafast time-domain spectroscopy based on high-speed asynchronous optical sampling.

High-speed asynchronous optical sampling (ASOPS) is a novel technique for ultrafast time-domain spectroscopy (TDS). It employs two mode-locked femtosecond oscillators operating at a fixed repetition frequency difference as sources of pump and probe pulses. We present a system where the 1 GHz pulse repetition frequencies of two Ti:sapphire oscillators are linked at an offset of Deltaf(R)=10 kHz. As a result, their relative time delay is repetitively ramped from zero to 1 ns within a scan time of 100 micros. Mechanical delay scanners common to conventional TDS systems are eliminated, thus systematic errors due to beam pointing instabilities and spot size variations are avoided when long time delays are scanned. Owing to the multikilohertz scan-rate, high-speed ASOPS permits data acquisition speeds impossible with conventional schemes. Within only 1 s of data acquisition time, a signal resolution of 6 x 10(-7) is achieved for optical pump-probe spectroscopy over a time-delay window of 1 ns. When applied to terahertz TDS, the same acquisition time yields high-resolution terahertz spectra with 37 dB signal-to-noise ratio under nitrogen purging of the spectrometer. Spectra with 57 dB are obtained within 2 min. A new approach to perform the offset lock between the two femtosecond oscillators in a master-slave configuration using a frequency shifter at the third harmonic of the pulse repetition frequency is employed. This approach permits an unprecedented time-delay resolution of better than 160 fs. High-speed ASOPS provides the functionality of an all-optical oscilloscope with a bandwidth in excess of 3000 GHz and with 1 GHz frequency resolution.

High-resolution THz spectrometer with kHz scan rates.

We demonstrate a rapid scanning high-resolution THz spectrometer capable of acquiring THz field transients with 1 ns duration without mechanical delay line. The THz spectrometer is based on two 1-GHz Ti:sapphire femtosecond lasers which are linked with a fixed repetition rate difference in order to perform high-speed asynchronous optical sampling. One laser drives a high-efficiency large-area GaAs based THz emitter, the other laser is used for electro-optic detection of the emitted THz-field. At a scan rate of 9 kHz a time resolution of 230 fs is accomplished. High-resolution spectra from 50 GHz up to 3 THz are obtained and water absorption lines with a width of 11 GHz are observed. The use of femtosecond lasers with 1 GHz repetition rate is essential to obtain rapid scanning and high time-resolution at the same time.

Anterior intramuscular transposition with ulnar nerve decompression at the elbow.

The effectiveness of decompression and anterior intramuscular transposition of the ulnar nerve for treatment of severe cubital tunnel syndrome was evaluated. A consecutive series of 39 anterior intramuscular transpositions were reviewed. One surgeon performed the transpositions between 1993 and 1997 in 34 patients who presented with clinically severe cubital tunnel syndrome. Clinical outcome and satisfaction with surgery were assessed. The results showed early clinical improvement of 77% of patients (mean followup, 3.34 months). With repeated assessments later, the same group of patients had clinical improvement of 62% (mean followup, 30.9 months). Patients younger than 50 years, individuals who underwent external neurolysis, or patients who had a previously failed subcutaneous transposition had fewer satisfactory results.

Decompression of the common peroneal nerve: experience with 20 consecutive cases.

A retrospective review of 20 patients with common peroneal nerve palsy treated with decompression between 1986 and 1997 was undertaken. Subjects were evaluated preoperatively and postoperatively by electromyography, nerve conduction, and clinical measures. The mean interval between the onset of symptoms to surgery (operative delay) was 15.9 months. The mean postoperative follow-up was 32.2 months with a minimum follow-up of 1 year. Decompression was performed at the level of the fibular neck and slightly distally at the tendinous origin of the peroneus longus using a standard approach to release tight fascial structures or scar tissue. External neurolysis was performed using the operating microscope in two cases for which scarring of the nerve was identified intraoperatively. Postoperatively, 19 of 20 patients showed improvement in ankle dorsiflexion as assessed by the Medical Research Council scale. Electromyographic examination was useful in the preoperative evaluation and selection of patients for decompression surgery. In conclusion, decompression even after a 1-year delay may offer benefit and suggest early intervention in patients with a severe lesion.

Microsurgical reconstruction of the through-and-through defect in head and neck cancer: is it worth it?

As health resources diminish, there are compelling reasons to utilize health dollars in a fiscally responsible manner. The reconstruction of complex oromandibular defects involving mucosa, bone, and skin coverage poses one of the greatest challenges in microsurgery of the head and neck. The cancer patient who requires a through-and-through resection and microsurgical reconstruction usually has a poor prognosis. In this study, the authors examine whether this type of surgery is worthwhile in terms of cost, functional outcome, and patient satisfaction. Of 16 cases of through-and-through oromandibular reconstruction performed, the survival outcome of ten (n = 10) advanced cases requiring immediate oromandibular reconstruction (7 radial forearm flaps; 3 scapular flaps) is presented. Six cases were considered cured and required delayed reconstruction. Seven of the 10 patients died within 39 months postoperatively, while three survived up to 68 months postoperatively. The combined experience of these ten patients was examined using the Kaplan-Meier (product-limit) estimator of the survival curve. Results show that of the seven patients who died of disease, five did so within the first postoperative year. More important, among those five patients who survived for more than one postoperative year, three were still alive up to 68 months, representing a combined total of over 15 postoperative years. The probability of long-term survival is good in through-and-through oromandibular cancer patients who can survive to 1 year postoperatively, and it is proposed that microsurgical reconstruction, albeit costly, remains a worthwhile procedure,

Oromandibular reconstruction with the radial-forearm osteocutaneous flap: experience with 60 consecutive cases.

One of the more difficult problems in reconstructive surgery of the head and neck is replacement of bone and soft tissue lost because of injury, osteomyelitis, or malignancy. The radial-forearm osteocutaneous flap is an accepted choice for oromandibular reconstruction. This study was undertaken to review one center's experience with 60 consecutive cases of oromandibular reconstruction with the radial-forearm osteocutaneous flap. Records of the 38 men and 22 women (mean age, 60 years; range, 26 to 86 years) were reviewed for tumor location, defect and bone length, flap failure rate, recipient- and donor-site complications, length of surgery, and hospital stay. Cancer resection was the reason for 97 percent of reconstructions; 33 percent of flaps were used to reconstruct a lateral defect of the mandible, 40 percent a lateral-central defect, and 27 percent a lateral-central-lateral defect. Mean skin flap size was 55 cm2 (range, 15 to 117 cm2) and mean bone length, 9.4 cm (range, 5 to 14 cm). The microvascular success rate was 98.3 percent. Complications included fracture of the donor radius (15 percent), nonunion of the mandible (5 percent), and hematoma (8.3 percent). These results are comparable to results reported in the literature with other radial forearm flaps. The free radial osteocutaneous flap is a safe and reliable choice for mandibular reconstruction. It offers sufficient bone to reconstruct large defects and can provide adequate pedicle length for vessel anastomosis to the contralateral side of the neck. The above attributes make the radial forearm osteocutaneous flap one of the "first line" flap choices for oromandibular reconstruction.

Preservation of denervated muscle by sensory protection in rats.

The goal of this study was to determine whether sensory motor nerve crossover could alter post-denervation atrophy of skeletal muscle. Sixty adult Lewis rats were divided into three groups: 1) unilateral transection of the tibial nerve alone; 2) unilateral transection of the tibial nerve with immediate repair; and 3) unilateral tibial and sural nerve transections with repair of the proximal sural nerve (sensory) to the distal tibial nerve (motor). The unoperated hind legs acted as positive controls. At 1 and 2 months postoperatively, posterior compartment musculature was harvested, weighed, then fixed and stained for histologic analysis. One month postoperatively, mean muscle weight in Group 1 animals (transection alone) was 23.0 +/- 2.6 percent of the control side; for Group 2 animals (motor-motor repair) was 40.9 +/- 42 percent; and for the sensory-protected Group 3 animals (sensory-motor repair) was 26.7 +/- 2.8 percent of controls (n = 15 per group). Two months postoperatively, the mean weights were 14.5 +/- 0.9 percent, 58.8 +/- 7.3 percent, and 21.1 +/- 3.1 percent of controls for Groups 1, 2, and 3, respectively (n = 5 per group). Differences between groups were statistically significant. Histologic analysis of Group 1 specimens revealed generalized atrophy of all muscle fibers. In Group 2, specimens showed evidence of reinnervation and less atrophy. Group 3 specimens demonstrated an atrophic pattern with islands of non-atrophic fibers scattered throughout. Sensory protection was thus shown to have significant effect on post-denervation atrophy in rat skeletal muscle.

The fate of the osteotomized free radial forearm osteocutaneous flap in mandible reconstruction.

The radial forearm osteocutaneous free flap has become a standard method of mandible reconstruction. In order to improve the contour of the reconstructed jaw in large resections, especially the anterior defect, the radial forearm bone graft needs to be osteotomized. The bone graft is nourished by small branches of the radial artery via the fascial connections between the skin flap and bone. The effect of the osteotomy, fixation devices, and the angulation of the bone segment on bone viability and eventual bone healing is not known. Forty-two radial forearm osteocutaneous flaps were used for composite mandible reconstruction. In 25 patients, the bone graft required osteotomy to achieve contour, of which 16 required single osteotomy and nine required double osteotomy. In a remaining 17 cases, no osteotomy was performed. Only those patients who had at least a 1-year follow-up were included in this study. The proportion of patients who achieved bone union was similar for both groups (i.e. osteotomy vs. nonosteotomy). Performing osteotomies on the segment of the radius in free osteocutaneous transfers is safe, and it allows for more flexibility in reconstruction, to achieve a natural-appearing jaw.

Surgical patterns of venous drainage of the free forearm flap in head and neck reconstruction.

A retrospective review of 40 consecutive free forearm flaps used in head and neck reconstruction in our Head and Neck Service identified five different patterns of venous drainage. In type 1, the cephalic vein and two venae comitantes join into a larger median cubital vein, which itself splits into two sizable branches (n = 8, two anastomoses). In type 2, a median cubital vein drains both the cephalic vein and the two venae comitantes (n = 17, single anastomosis). In type 3, the cephalic vein and the confluence of two venae comitantes are drained separately (n = 7, two anastomoses). In type 4, the cephalic vein and each of two venae comitantes are anastomosed separately (n = 2, three separate anastomoses). In type 5, the cephalic vein and the larger of the two venae comitantes are drained separately (n = 6, two anastomoses). Understanding these possible venous drainage patterns substantially expedites the raising of the free forearm flap. The selection of patterns 1 and 2, when possible, with the large-caliber veins ensures the safety of the flap. Long vascular pedicles permit anastomoses to contralateral neck recipient vessels, obviating vein grafts, and permit safe full head and neck mobility.