Hanbury Brown and Twiss correlations--correlations in far-field intensity fluctuations--yield fundamental information on the quantum statistics of light sources, as demonstrated after the discovery ...of photon bunching1, 2, 3. Drawing on the analogy between photons and atoms, similar measurements have been performed for matter-wave sources, probing density fluctuations of expanding ultracold Bose gases4, 5, 6, 7, 8. Here we use two-point density correlations to study how coherence is gradually established when crossing the Bose-Einstein condensation threshold. Our experiments reveal a persistent multimode character of the emerging matter-wave as seen in the non-trivial spatial shape of the correlation functions for all probed source geometries, from nearly isotropic to quasi-one-dimensional, and for all probed temperatures. The qualitative features of our observations are captured by ideal Bose gas theory9, whereas the quantitative differences illustrate the role of particle interactions. PUBLICATION ABSTRACT
Dentin hypersensitivity is a frequent finding especially in periodontitis patients. Conventional treatment aims for obstruction of dentin tubules by disabling liquid and osmotic fluctuation to and ...from the pulpal chamber. A novel bioglass-based desensitizer was shown to obstruct tubules and to resist periodic exposure to lactic acid. Whether this obstruction is resistant to brushing had not been tested so far. Accordingly, the present study aimed to assess dentin tubule obstruction after repeated acid exposure and brushing.
Sixty dentin discs were cleaned with 17% EDTA, mounted into a pulp fluid simulator and randomly divided into 3 groups: No surface treatment in Group A, Seal&Protect® in group B and DentinoCer in group C. Discs were exposed to 0.1 M non-saturated lactic acid thrice and standardized brushing twice a day for 12 days. At baseline and after 2, 4 and 12 d samples were removed from the setting and prepared for top-view SEM analysis to assess tubule obstruction using the Olley score. Discs were then vertically cut and the section surface morphologically assessed using backscatter imaging. For both vertical and sectional surfaces EDX analysis was used to characterize the surface composition in the tubular and inter-tubular area.
Group A showed clean tubular lumina at all time points. From day 2 onwards dentin showed exposed collagen fibers. Group 2 initially showed a complete surface coverage that flattened out during treatment without ever exposing tubules. At baseline, samples of Group C displayed a complete homogeneous coverage. From day 2 on tubules entrances with obstructed lumen became visible. While on day 4 and 12 the dentin surface exposed collagen fibers the lumina remained closed. EDX analysis of the vertical and horizontal views showed that P and Ca were predominant elements in both the inter- and tubular dentin while Si peaks were found in the tubule plugs.
While group B displayed a packed layer on the surface during the whole investigation time group C samples lost their superficial layer within 48 h. Tubule plugs containing considerable Si proportions indicated previous presence of DentinoCer, while high Ca and P proportions suggest obturation by dentin-like material.
We present a novel imaging system for ultracold quantum gases in expansion. After release from a confining potential, atoms fall through a sheet of resonant excitation laser light and the emitted ...fluorescence photons are imaged onto an amplified CCD camera using a high numerical aperture optical system. The imaging system reaches an extraordinary dynamic range, not attainable with conventional absorption imaging. We demonstrate single-atom detection for dilute atomic clouds with high efficiency where at the same time dense Bose-Einstein condensates can be imaged without saturation or distortion. The spatial resolution can reach the sampling limit as given by the 8μm pixel size in object space. Pulsed operation of the detector allows for slice images, a first step toward a three-dimensional (3D) tomography of the measured object. The scheme can easily be implemented for any atomic species and all optical components are situated outside the vacuum system. As a first application we perform thermometry on rubidium Bose-Einstein condensates created on an atom chip
We realize a one-dimensional Josephson junction using quantum degenerate Bose gases in a tunable double well potential on an atom chip. Matter wave interferometry gives direct access to the relative ...phase field, which reflects the interplay of thermally driven fluctuations and phase locking due to tunneling. The thermal equilibrium state is characterized by probing the full statistical distribution function of the two-point phase correlation. Comparison to a stochastic model allows us to measure the coupling strength and temperature and hence a full characterization of the system.
To stabilize the distal radioulnar joint (DRUJ) by performing dorsal capsular imbrication in patients presenting with dorsal instability. The goal was to reduce pain and prevent the occurrence of ...posttraumatic arthrosis.
Posttraumatic dorsal instability of the DRUJ with missing block while performing translational activities in the DRUJ or subluxation while actively rotating the forearm. Cases, in which other stabilizing techniques, such as, sutures of the triangular fibrocartilage complex failed.
DRUJ arthrosis, previous surgical interventions to the capsule area of the DRUJ, instabilities due to osseous reasons (malposition or pseudarthrosis) should already have been treated.
Dorsal approach and opening of the 5th extensor compartment to expose the dorsal joint capsule. A longitudinal division of the capsule was performed and sufficient tissue on the radial and ulnar border was retained to ensure a solid suture technique. Then 2 U-shaped sutures using FiberWire suture material were made. Correction of the malposition and repositioning the forearm into supination. Tightening of the prepared capsule sutures and closing of the retinaculum with a resorbable suture.
Patients wore a long-arm cast with the forearm being in supination for a period of 4 weeks. Following cast removal, patients wore a forearm splint for a period of 4 weeks to limit forearm pronation/supination at 45°. Full load on the wrist was allowed after 12 weeks.
The subjective and functional outcomes of 20 patients having received capsular imbrication using this technique were good and entailed no significant complications. The postoperative DASH was 15.8 points. Of the 20 patients, 17 patients (85%) had a reduction of pain. Symptoms of DRUJ instability could be reduced in 18 patients (90%). Pronation/supination of the wrist was not restricted postoperatively.
Sulcus ulnaris syndrome is the second most common neurocompression syndrome in the upper limb after carpal tunnel syndrome. Its severity can be appreciated by the Dellon Classification. We present ...our experience and results after endoscopic decompression.
A retrospective chart review of 55 patients operated over a 3-year period was performed. The patients, 37 men and 18 women, had an average age of 54 years (range: 27-82 years) at the time of surgery. The clinical diagnostic was always confirmed by a neurophysiological examination of the nerve conduction. According to the Dellon Classification, 11 patients had mild sulcus ulnaris syndrome, 31 had moderate and 13 had severe. The mean follow-up time was 21 months (range: 6-42 months).
The sensibility was normalised in 85% of the patients. Compared to the contralateral non-operated side, the mean grip strength improved from 68 to 94% and the mean pinch grip from 72 to 95%. The rate of nerve luxation did not change (5.5%). According to the modified Bishop rating system, 38 patients (69%) had excellent, 13 patients (23.5%) good and four patients (7.5%) fair results. One haematoma necessitating a revision, a minimal lesion of the ulnar nerve with restitution ad integrum and a hypoesthesia of the elbow, occurred after surgery resulting in a complication rate of 5.5%. Ninety-eight percent of the patients responded that they would undergo the endoscopic procedure again if needed.
Endoscopic decompression of the ulnar nerve in sulcus ulnaris syndrome is very well appreciated by patients and also provides promising clinical results.
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