Probing the Degree of Coherence through the Full 1D to 3D Crossover.

We experimentally study a gas of quantum degenerate ^{87}Rb atoms throughout the full dimensional crossover, from a one-dimensional (1D) system exhibiting phase fluctuations consistent with 1D theory to a three-dimensional (3D) phase-coherent system, thereby smoothly interpolating between these distinct, well-understood regimes. Using a hybrid trapping architecture combining an atom chip with a printed circuit board, we continuously adjust the system's dimensionality over a wide range while measuring the phase fluctuations through the power spectrum of density ripples in time-of-flight expansion. Our measurements confirm that the chemical potential µ controls the departure of the system from 3D and that the fluctuations are dependent on both µ and the temperature T. Through a rigorous study we quantitatively observe how inside the crossover the dependence on T gradually disappears as the system becomes 3D. Throughout the entire crossover the fluctuations are shown to be determined by the relative occupation of 1D axial collective excitations.

Kirkwood-Buff integrals: From fluctuations in finite volumes to the thermodynamic limit.

The Kirkwood-Buff theory is a cornerstone of the statistical mechanics of liquids and solutions. It relates volume integrals over the radial distribution function, so-called Kirkwood-Buff integrals (KBIs), to particle number fluctuations and thereby to various macroscopic thermodynamic quantities such as the isothermal compressibility and partial molar volumes. Recently, the field has seen a strong revival with breakthroughs in the numerical computation of KBIs and applications to complex systems such as bio-molecules. One of the main emergent results is the possibility to use the finite volume KBIs as a tool to access finite volume thermodynamic quantities. The purpose of this Perspective is to shed new light on the latest developments and discuss future avenues.

[Radiological evaluation of acute abdomen in children]. / Radiologische Abklärung des akuten Abdomens im Kindesalter.

CLINICAL/METHODICAL ISSUE: Acute, non-traumatic abdominal pain is one of the main reasons for medical consultation in pediatric patients. Knowledge of different diseases and their age dependence is essential for correct diagnosis and treatment. STANDARD RADIOLOGICAL METHODS: Ultrasonography is the imaging method of choice. X­ray is only used in case of emergency, e. g., suspected perforation. METHODICAL INNOVATIONS: Contrast-enhanced ultrasonography (CEUS) and elastography complement ultrasonography. PERFORMANCE: Magnetic resonance imaging is of increasing relevance for differential diagnosis of unclear sonographic results. PRACTICAL RECOMMENDATIONS: The primary imaging modality in pediatric patients is ultrasonography. Cross-sectional imaging should only be used in cases of unclear sonographic findings.

MasterOnline Periodontology and Implant Therapy-revisited after seven years: A case study of the structures and outcomes in a blended learning CPD.

INTRODUCTION: There is a great need for postgraduate training and continuing professional development (CPD), specifically in the field of periodontology. Despite the plenty of periodontal CPDs, there is a lack of information about the performance of CPDs in a blended learning setting. This study is a case study of the structures and outcomes in a blended learning CPD programme in periodontology, the MasterOnline Periodontology and Implant Therapy hosted by the University of Freiburg's Dental School. MATERIAL AND METHODS: The structures of the blended learning CPD were analysed with the aims to (i) make explicit how various innovative educational methods and ICT tools can be successfully applied to a Web-supported postgraduate periodontology training programme, (ii) identify the programme's impact on learning transfer in students' dental practices and (iii) identify other outcomes, synergies and any changes required during the existence. Using qualitative interviewing, the various types of learning transfer and elements of the study programme that foster transfer could be exemplified. RESULTS: A period of 7 years was analysed. In this duration, 50 students successfully graduated to a master of science. Qualitative interviews were performed with six students and four teachers affirming the learning transfer in a blended learning setting. CONCLUSIONS: This case study shows that blended learning can be a successful approach for CPD in dentistry.

An oral health optimized diet can reduce gingival and periodontal inflammation in humans - a randomized controlled pilot study.

BACKGROUND: The aim of this pilot study was to investigate the effects of four weeks of an oral health optimized diet on periodontal clinical parameters in a randomized controlled trial. METHODS: The experimental group (n = 10) had to change to a diet low in carbohydrates, rich in Omega-3 fatty acids, and rich in vitamins C and D, antioxidants and fiber for four weeks. Participants of the control group (n = 5) did not change their dietary behavior. Plaque index, gingival bleeding, probing depths, and bleeding upon probing were assessed by a dentist with a pressure-sensitive periodontal probe. Measurements were performed after one and two weeks without a dietary change (baseline), followed by a two week transitional period, and finally performed weekly for four weeks. RESULTS: Despite constant plaque values in both groups, all inflammatory parameters decreased in the experimental group to approximately half that of the baseline values (GI: 1.10 ± 0.51 to 0.54 ± 0.30; BOP: 53.57 to 24.17 %; PISA: 638 mm(2) to 284 mm(2)). This reduction was significantly different compared to that of the control group. CONCLUSION: A diet low in carbohydrates, rich in Omega-3 fatty acids, rich in vitamins C and D, and rich in fibers can significantly reduce gingival and periodontal inflammation. TRIAL REGISTRATION: German Clinical Trials Register; https://www.germanctr.de (DRKS00006301). Registered on 2015-02-21.

Electron-Phonon Coupling in the Bulk of Anatase TiO2 Measured by Resonant Inelastic X-Ray Spectroscopy.

We investigate the polaronic ground state of anatase TiO2 by bulk-sensitive resonant inelastic x-ray spectroscopy (RIXS) at the Ti L3 edge. We find that the formation of the polaron cloud involves a single 95 meV phonon along the c axis, in addition to the 108 meV ab-plane mode previously identified by photoemission. The coupling strength to both modes is the same within error bars, and it is unaffected by the carrier density. These data establish RIXS as a directional bulk-sensitive probe of electron-phonon coupling in solids.

One-dimensional transport of bosons between weakly linked reservoirs.

We study a flow of ultracold bosonic atoms through a one-dimensional channel that connects two macroscopic three-dimensional reservoirs of Bose-condensed atoms via weak links implemented as potential barriers between each of the reservoirs and the channel. We consider reservoirs at equal chemical potentials so that a superflow of the quasicondensate through the channel is driven purely by a phase difference 2Φ imprinted between the reservoirs. We find that the superflow never has the standard Josephson form ∼sin2Φ. Instead, the superflow discontinuously flips direction at 2Φ=±π and has metastable branches. We show that these features are robust and not smeared by fluctuations or phase slips. We describe a possible experimental setup for observing these phenomena.

Lipid profiles and persisting inflammation following critical illness in a central Australian population: a prospective longitudinal observational study.

No published data exist following the changes in lipid profile during and after an episode of acute illness for the Australian Indigenous population. This paper presents data focusing on lipid profiles and inflammatory markers in a group of survivors of critical illness in Central Australia, prospectively recruited to a larger trial exploring the medium-term sequelae of an intensive care unit admission. This data confirm that lipid profiles in acute illness are deranged, and that recovery may differ between indigenous and non-indigenous populations.

MR microscopy of the human finger and correlation with histology--a proof-of-principle study.

Magnetic resonance imaging (MRI) with small surface coils is a well established method for the diagnostic evaluation of finger masses. Until now, histological examination has been required to reliably assess tumor extent and infiltration of surrounding structures. Ultra-high-field MR microscopy (MRM) allows evaluation of anatomical structures and pathologies with submillimeter resolution. This study describes the diagnostic prospects and potential of MRM based on the ex-vivo examination of different finger pathologies. Ten human digits were examined by ex-vivo MRM at 7.1 Tesla (ClinScan, Bruker BioScan) using a T2-weighted turbo spin echo (TSE) sequence. Imaging parameters were: TE 48 ms; TR 8370 ms; slice thickness 700 µm; matrix size 1024 × 1024 pixels; FOV 37 × 37 mm; in-plane resolution 36 × 36 µm/voxel. Afterwards specimens were examined histologically. Histology and MRM were correlated. MRM allowed evaluation of the anatomy of the nail, the tendon insertions, the distal interphalangeal joint, and the neurovascular bundles. Finger abnormalities evaluated by MRM included osteomyelitis and metastatic disease. Subsequent histological examination confirmed MRM findings regarding origin, internal makeup, and extent of the structures visualized. This study demonstrates the potential of MRM for imaging small anatomical structures and pathologies of the human finger. Our ex-vivo findings correlate strongly with histology, suggesting that MRM may gain a central role in assessing anatomical structures and pathology in terms of morphology, extent, and infiltration of surrounding structures. Therefore, with increasing availability, MRM is expected to become an essential tool not only in experimental studies but also for daily routine.

Intrinsic nature of the excess electron distribution at the TiO2(110) surface.

The gap state that appears upon reduction of TiO2 plays a key role in many of titania's interesting properties but its origin and spatial localization have remained unclear. In the present work, the TiO2(110) surface is reduced in a chemically controlled way by sodium adsorption. By means of resonant photoelectron diffraction, excess electrons are shown to be distributed mainly on subsurface Ti sites strikingly similar to the defective TiO2(110) surface, while any significant contribution from interstitial Ti ions is discarded. In agreement with first principles calculations, these findings demonstrate that the distribution of the band gap charge is an intrinsic property of TiO2(110), independent of the way excess electrons are produced.

Electronic structure changes across the metamagnetic transition in FeRh via hard X-ray photoemission.

Stoichiometric FeRh undergoes a temperature-induced antiferromagnetic (AFM) to ferromagnetic (FM) transition at ~350 K. In this Letter, changes in the electronic structure accompanying this transition are investigated in epitaxial FeRh thin films via bulk-sensitive valence-band and core-level hard x-ray photoelectron spectroscopy with a photon energy of 5.95 keV. Clear differences between the AFM and FM states are observed across the entire valence-band spectrum and these are well reproduced using density-functional theory. Changes in the 2p core levels of Fe are also observed and interpreted using Anderson impurity model calculations. These results indicate that significant electronic structure changes over the entire valence-band region are involved in this AFM-FM transition.

Can easy-to-use software deliver effective e-learning in dental education? A randomised controlled study.

INTRODUCTION: For the production of computer-based learning environments, a wide range of software solutions can be used which differ not only in their functionality but also vary in cost and ease to program. The aim of our study was to evaluate the overall efficiency and student's perception of two case-based e-learning programs that were produced with either an easy-to-use or a complex software. MATERIALS AND METHODS: Eighty-five dental students were randomly assigned to one of two experimental groups. One group studied with a laborious, high-interactive e-learning program (complex-software group). The second group studied within a low-interactive learning environment (easy-software group) that was easy to be programmed. Both programs identically referred to a case report on localised aggressive periodontitis. Learning outcome was tested by a pre- and post-test. Furthermore, questionnaires on workload, motivation, perceived usefulness and perceived learning outcome were used. RESULTS: Learners in the easy-software group showed better results in the post-test F(1, 82) = 4.173, P < 0.044). DISCUSSION: Even easy-to-use software tools have the potential to be beneficial in dental education. Students were showing a high acceptance and ability in using both e-learning environments. CONCLUSIONS: We conclude that e-learning programs for case-based learning do not have to be overly laborious to program to be useful. Based on our results, we want to encourage instructors to produce case-based e-learning tools with easy-to-use software.

The importance of teaching communication in dental education. A survey amongst dentists, students and patients.

The aim of our study was to evaluate the subjective importance of teaching communication in the dental curriculum by conducting a survey amongst dentists, students and patients. Three questionnaires about communication-related issues were developed in which different questions could be rated on a five-point Likert scale. These questions included the subjective importance of the dental team's friendliness, an elaborated consultation, modern office equipment or the dentist's technical skills. Seven hundred and twenty-nine questionnaires were completed [233 by dentists (32%), 310 by students (43%) and 185 by patients (25%)]. Eighty-seven percentage of the dentists, 84% of the students and 84% of the patients supported an integration of communicational issues in dental education; 94.7% of the dentists and 77.2% of the patients attached vital importance to the dentist-patient relationship regarding the therapeutic outcomes. Dentists with prior communicational training experience would spend significantly (P<0.001) more money for further courses. The results show the publicly perceived importance of integrating aspects of communication in dental education.

High resolution photoemission and x-ray absorption spectroscopy of a lepidocrocite-like TiO2 nanosheet on Pt(110) (1 × 2).

The electronic structure of TiO(2) nanosheets on the Pt(110)-(1 × 2) surface has been investigated by using high resolution photoemission spectroscopy and x-ray absorption spectroscopy (XAS). The Ti 2p XAS spectra of the deposited TiO(2) films have been theoretically evaluated and, from the comparison with the experimental data, the assignment to a lepidocrocite-like structure is confirmed. Coexistence of TiO(2) islands with PtO(2) stripes for incomplete nanosheets is confirmed by high resolution photoemission data. The location of the valence and conduction band edges of the nanosheet has been experimentally determined allowing us to describe in details subtle electronic effects due to the interface with the substrate. The locations of the valence band maximum and the leading peak in the O 1s XAS spectrum indicate a band gap similar to anatase but with the Fermi level closer to mid-gap than found for bulk, n-type TiO(2).

Weakly interacting Bose gas in the one-dimensional limit.

We prepare a chemically and thermally one-dimensional (1D) quantum degenerate Bose gas in a single microtrap. We introduce a new interferometric method to distinguish the quasicondensate fraction of the gas from the thermal cloud at finite temperature. We reach temperatures down to kT≈0.5ℏω(⊥) (transverse oscillator eigenfrequency ω(⊥)) when collisional thermalization slows down as expected in 1D. At the lowest temperatures the transverse-momentum distribution exhibits a residual dependence on the line density n(1D), characteristic for 1D systems. For very low densities the approach to the transverse single-particle ground state is linear in n(1D).

Optical lattice on an atom chip.

Optical dipole traps and atom chips are two very powerful tools for the quantum manipulation of neutral atoms. We demonstrate that both methods can be combined by creating an optical lattice potential on an atom chip. A red-detuned laser beam is retroreflected using the atom chip surface as a high-quality mirror, generating a vertical array of purely optical oblate traps. We transfer thermal atoms from the chip into the lattice and observe cooling into the two-dimensional regime. Using a chip-generated Bose-Einstein condensate, we demonstrate coherent Bloch oscillations in the lattice.

Cavernous sinus thrombosis and meningitis from community-acquired methicillin-resistant Staphylococcus aureus infection.

Septic cavernous sinus thrombosis is an uncommon clinical syndrome with a high morbidity and mortality. The commonest bacterial pathogen is Staphylococcus aureus. We describe the study of a patient with cavernous sinus thrombosis and meningitis caused by community-acquired methicillin-resistant S. aureus (CA-MRSA) infection. The isolate was genotyped as the ST93 (Queensland) clone of CA-MRSA and carried the Panton-Valentine leucocidin genes. Cure was obtained following prolonged antimicrobial therapy with vancomycin, rifampicin, cotrimoxazole and linezolid. Given the high morbidity and mortality of cavernous sinus thrombosis and the worldwide recent emergence of CA-MRSA, clinicians treating patients with this infection should consider early empirical coverage for CA-MRSA with an antimicrobial agent, such as vancomycin or linezolid, particularly in the presence of suspected facial staphylococcal skin infections. If vancomycin is used, we emphasize that high doses may be required to achieve even low levels in the cerebrospinal fluid.