DEVELOPING twin-specific 75-g oral glucose tolerance test diagnostic thresholds for gestational diabetes based on the risk of future maternal diabetes: a population-based cohort study

OBJECTIVE

To develop twin-specific outcome-based oral glucose tolerance test (OGTT) diagnostic thresholds for GDM based on the risk of future maternal type-2 diabetes.

DESIGN

A population-based retrospective cohort study (2007-2017).

SETTING

Ontario, Canada.

METHODS

Nulliparous women with a live singleton (n = 55 361) or twin (n = 1308) birth who underwent testing for gestational diabetes mellitus (GDM) using a 75-g OGTT in Ontario, Canada (2007-2017). We identified the 75-g OGTT thresholds in twin pregnancies that were associated with similar incidence rates of future type-2 diabetes to those associated with the standard OGTT thresholds in singleton pregnancies.

RESULTS

For any given 75-g OGTT value, the incidence rate of future maternal type-2 diabetes was lower for women with a twin than women with a singleton pregnancy. Using women with a negative OGTT as reference, the risk of future maternal type-2 diabetes in twin pregnancies with a positive OGTT based on the standard OGTT thresholds (9.86 per 1000 person years, adjusted hazard ratio (aHR) 4.79, 95% CI 2.69-8.51) was lower than for singleton pregnancies with a positive OGTT (18.74 per 1000 person years, aHR 8.22, 95% CI 7.38-9.16). The twin-specific OGTT fasting, 1-hour and 2-hour thresholds identified in the current study based on correlation with future maternal type-2 diabetes were 5.8 mmol/l (104 mg/dl), 11.8 mmol/l (213 mg/dl) and 10.4 mmol/l (187 mg/dl), respectively.

CONCLUSIONS

We identified potential twin-specific OGTT thresholds for GDM that are associated with a similar risk of future type-2 diabetes to that observed in women diagnosed with GDM in singleton pregnancies based on standard OGTT thresholds.

TWEETABLE ABSTRACT

Potential twin-specific OGTT thresholds for GDM were identified.

Light-Induced Renormalization of the Dirac Quasiparticles in the Nodal-Line Semimetal ZrSiSe

In nodal-line semimetals, linearly dispersing states form Dirac loops in the reciprocal space with a high degree of electron-hole symmetry and a reduced density of states near the Fermi level. The result is reduced electronic screening and enhanced correlations between Dirac quasiparticles. Here we investigate the electronic structure of ZrSiSe, by combining time- and angle-resolved photoelectron spectroscopy with ab initio density functional theory (DFT) complemented by an extended Hubbard model (DFT+U+V) and by time-dependent DFT+U+V. We show that electronic correlations are reduced on an ultrashort timescale by optical excitation of high-energy electrons-hole pairs, which transiently screen the Coulomb interaction. Our findings demonstrate an all-optical method for engineering the band structure of a quantum material.

Two-Dimensional Conical Dispersion in ZrTe_{5} Evidenced by Optical Spectroscopy

Zirconium pentatelluride was recently reported to be a 3D Dirac semimetal, with a single conical band, located at the center of the Brillouin zone. The cone's lack of protection by the lattice symmetry immediately sparked vast discussions about the size and topological or trivial nature of a possible gap opening. Here, we report on a combined optical and transport study of ZrTe_{5}, which reveals an alternative view of electronic bands in this material. We conclude that the dispersion is approximately linear only in the a-c plane, while remaining relatively flat and parabolic in the third direction (along the b axis). Therefore, the electronic states in ZrTe_{5} cannot be described using the model of 3D Dirac massless electrons, even when staying at energies well above the band gap 2Δ=6  meV found in our experiments at low temperatures.

Evidence of a Coulomb-Interaction-Induced Lifshitz Transition and Robust Hybrid Weyl Semimetal in T_{d}-MoTe_{2}

Using soft x-ray angle-resolved photoemission spectroscopy we probed the bulk electronic structure of T_{d}-MoTe_{2}. We found that on-site Coulomb interaction leads to a Lifshitz transition, which is essential for a precise description of the electronic structure. A hybrid Weyl semimetal state with a pair of energy bands touching at both type-I and type-II Weyl nodes is indicated by comparing the experimental data with theoretical calculations. Unveiling the importance of Coulomb interaction opens up a new route to comprehend the unique properties of MoTe_{2}, and is significant for understanding the interplay between correlation effects, strong spin-orbit coupling and superconductivity in this van der Waals material.

Manipulation of skyrmion motion by magnetic field gradients

Magnetic skyrmions are particle-like, topologically protected magnetisation entities that are promising candidates as information carriers in racetrack memory. The transport of skyrmions in a shift-register-like fashion is crucial for their embodiment in practical devices. Here, we demonstrate that chiral skyrmions in Cu2OSeO3 can be effectively manipulated under the influence of a magnetic field gradient. In a radial field gradient, skyrmions were found to rotate collectively, following a given velocity-radius relationship. As a result of this relationship, and in competition with the elastic properties of the skyrmion lattice, the rotating ensemble disintegrates into a shell-like structure of discrete circular racetracks. Upon reversing the field direction, the rotation sense reverses. Field gradients therefore offer an effective handle for the fine control of skyrmion motion, which is inherently driven by magnon currents. In this scheme, no local electric currents are needed, thus presenting a different approach to shift-register-type operations based on spin transfer torque.

Note: Commercial SQUID magnetometer-compatible NMR probe and its application for studying a quantum magnet

We present a compact nuclear magnetic resonance (NMR) probe which is compatible with a magnet of a commercial superconducting quantum interference device magnetometer and demonstrate its application to the study of a quantum magnet. We employ trimmer chip capacitors to construct an NMR tank circuit for low temperature measurements. Using a magnetic insulator MoOPO₄ with S = 1/2 (Mo⁵⁺) as an example, we show that the T-dependence of the circuit is weak enough to allow the ligand-ion NMR study of magnetic systems. Our ³¹P NMR results are compatible with previous bulk susceptibility and neutron scattering experiments and furthermore reveal unconventional spin dynamics.

Anträge auf psychosomatische Rehabilitation – Häufigkeit, Qualität und Befürwortungsrate

Hintergrund: Der Anteil an psychischen Hauptdiagnosen hat bei den medizinischen Rehabilitationsleistungen der DRV in den letzten Jahren stetig zugenommen. Bisher existieren kaum Daten über Häufigkeit, Qualität und Befürwortungsquote von Anträgen auf eine psychosomatische Reha. Prüfärzte der DRV benötigen im Rehabilitationsantrag ausreichend Informationen über Rehabedarf, -motivation, -fähigkeit und -prognose eines Versicherten. Der ärztliche Befundbericht bei Reha-Anträgen von Patienten mit psychischer Hauptdiagnose wird oft durch den Hausarzt erstellt. Psychische Störungen werden von Hausärzten häufig fehlerhaft diagnostiziert.

Methodik: Bei der DRV Nordbayern und der DRV Bayern Süd wurden über 2 Wochen die prüfärztlichen Entscheidungen bei Reha-Anträgen im Rahmen einer prospektiven Aktenanalyse dokumentiert. Für jeden eingehenden Reha-Antrag wurden folgende Angaben notiert: psychische und somatische Hauptdiagnose/n, Vorliegen von Befundberichten, Angaben zu psychiatrischen/psychotherapeutischen Vorbehandlungen, nachträgliche Anforderung von weiteren Entscheidungsgrundlagen sowie die prüfärztliche Entscheidung.

Ergebnisse: Insgesamt konnten 1 366 Anträge (davon 81% Erstvorlagen) analysiert werden. 16,2% der Erstvorlagen stammen von Antragstellern mit psychischen Hauptdiagnosen. 44,0% dieser Anträge liegt nur ein Befundbericht vom Hausarzt bei. Der Anteil an nicht befürworteten (34,7%) und noch offenen Anträgen (27,2%) liegt bei Reha-Anträgen von Antragstellern mit psychischen Hauptdiagnosen höher als bei Antragstellern mit rein somatischen Hauptdiagnosen (19,6% nicht befürwortete, 12,7% offene Anträge) (χ2=79,8(4), p=0,001). Reha-Anträge von Patienten mit psychischen Hauptdiagnosen ohne Befundbericht vom Psychiater/Psychotherapeuten werden häufiger nicht befürwortet (45,3 vs. 32,3%) oder werden bei der Erstvorlage nicht entschieden (28,0 vs. 18,3%) (χ2=10,2(2), p=0,006). Unter Antragstellern, die bereits in psychiatrischer/psychotherapeutischer Vorbehandlung waren, zeigt sich bei Reha-Anträgen mit Befundbericht vom Hausarzt nur noch ein höherer Anteil an nicht entschiedenen Anträgen (35,7 vs. 18,2%). Bei nicht entschiedenen Anträgen mit Befundbericht vom Hausarzt wird am häufigsten (68,9%) noch ein Befundbericht vom Psychiater/Psychotherapeuten nachgefordert.

Schlussfolgerung: Um die Aussagekraft von Anträgen mit psychischer Erstdiagnose bzw. Anträgen auf eine psychosomatische Rehabilitation zu erhöhen und eine raschere Entscheidung und eine bessere Indikationsstellung zu ermöglichen, könnte es sinnvoll sein, Befundberichte von vornherein von Fachärzten für Psychiatrie oder Psychotherapeuten erstellen zu lassen.

Development and Implementation of an Analysis Tool for Array-based Comparative Genomic Hybridization

Objectives: Array-comparative genomic hybridization (aCGH) is a high-throughput method to detect and map copy number aberrations in the genome. Multi-step analysis of high-dimensional data requires an integrated suite of bioinformatic tools. In this paperwe detail an analysis pipeline for array CGH data.

Methods: We developed an analysis tool for array CGH data which supports single and multi-chip analyses as well as combined analyses with paired mRNA gene expression data. The functions supporting relevant steps of analysis were implemented using the open source software R and combined as package aCGHPipeline. Analysis methods were illustrated using 189 CGH arrays of aggressive B-cell lymphomas.

Results: The package covers data input, quality control, normalization, segmentation and classification. For multi-chip analysis aCGHPipeline offers an algorithm for automatic delineation of recurrent regions. This task was performed manuallyup to now. The package also supports combined analysis with mRNA gene expression data. Outputs consist of HTML documents to facilitate communication with clinical partners.

Conclusions: The R package aCGHPipeline supports basic tasks of single and multi-chip analysis of array CGH data.

Linearly polarized GHz magnetization dynamics of spin helix modes in the ferrimagnetic insulator Cu2OSeO3

Linear dichroism - the polarization dependent absorption of electromagnetic waves- is routinely exploited in applications as diverse as structure determination of DNA or polarization filters in optical technologies. Here filamentary absorbers with a large length-to-width ratio are a prerequisite. For magnetization dynamics in the few GHz frequency regime strictly linear dichroism was not observed for more than eight decades. Here, we show that the bulk chiral magnet Cu₂OSeO₃ exhibits linearly polarized magnetization dynamics at an unexpectedly small frequency of about 2 GHz at zero magnetic field. Unlike optical filters that are assembled from filamentary absorbers, the magnet is shown to provide linear polarization as a bulk material for an extremely wide range of length-to-width ratios. In addition, the polarization plane of a given mode can be switched by 90° via a small variation in width. Our findings shed a new light on magnetization dynamics in that ferrimagnetic ordering combined with antisymmetric exchange interaction offers strictly linear polarization and cross-polarized modes for a broad spectrum of sample shapes at zero field. The discovery allows for novel design rules and optimization of microwave-to-magnon transduction in emerging microwave technologies.

Evolution of the Fermi surface of BiTeCl with pressure

We report measurements of Shubnikov-de Haas oscillations in the giant Rashba semiconductor BiTeCl under applied pressures up to  ∼2.5 GPa. We observe two distinct oscillation frequencies, corresponding to the Rashba-split inner and outer Fermi surfaces. BiTeCl has a conduction band bottom that is split into two sub-bands due to the strong Rashba coupling, resulting in two spin-polarized conduction bands as well as a Dirac point. Our results suggest that the chemical potential lies above this Dirac point, giving rise to two Fermi surfaces. We use a simple two-band model to understand the pressure dependence of our sample parameters. Comparing our results on BiTeCl to previous results on BiTeI, we observe similar trends in both the chemical potential and the Rashba splitting with pressure.

Endoscopic rendez-vous reconstruction of complete biliary obstruction

BACKGROUND AND STUDY AIMS

Complete biliary strictures normally require surgical intervention. We describe an alternative, minimally invasive endoscopic/percutaneous rendez-vous technique for the reconstruction of complete benign biliary strictures.

PATIENTS AND METHODS

Complete biliary strictures were reconstructed in four patients using a rendez-vous percutaneous-endoscopic or percutaneous-percutaneous route guided by fluoroscopic and visual (transillumination) control.

RESULTS

All four patients were treated successfully and safely with the rendez-vous technique. Complications were caused by the preliminary creation, dilatation and maturation of the percutaneous tract.

CONCLUSION

This technique may offer a good alternative to surgical bilio-enteric anastomosis in experienced hands. The long term course of the patients treated remains to be seen.

Dimensional Crossover in a Charge Density Wave Material Probed by Angle-Resolved Photoemission Spectroscopy

High-resolution angle-resolved photoemission spectroscopy data reveal evidence of a crossover from one-dimensional (1D) to three-dimensional (3D) behavior in the prototypical charge density wave (CDW) material NbSe_{3}. In the low-temperature 3D regime, gaps in the electronic structure are observed due to two incommensurate CDWs, in agreement with x-ray diffraction and electronic-structure calculations. At higher temperatures we observe a spectral weight depletion that approaches the power-law behavior expected in one dimension. From the warping of the quasi-1D Fermi surface at low temperatures, we extract the energy scale of the dimensional crossover. This is corroborated by a detailed analysis of the density of states, which reveals a change in dimensional behavior dependent on binding energy. Our results offer an important insight into the dimensionality of excitations in quasi-1D materials.

Dynamical Defects in Rotating Magnetic Skyrmion Lattices

The chiral magnet Cu_{2}OSeO_{3} hosts a Skyrmion lattice that may be equivalently described as a superposition of plane waves or a lattice of particlelike topological objects. A thermal gradient may break up the Skyrmion lattice and induce rotating domains, raising the question of which of these scenarios better describes the violent dynamics at the domain boundaries. Here, we show that in an inhomogeneous temperature gradient caused by illumination in a Lorentz transmission electron microscope different parts of the Skyrmion lattice can be set into motion with different angular velocities. Tracking the time dependence, we show that the constant rearrangement of domain walls is governed by dynamic 5-7 defects arranging into lines. An analysis of the associated defect density is described by Frank's equation and agrees well with classical 2D Monte Carlo simulations. Fluctuations of boundaries show a surgelike rearrangement of Skyrmion clusters driven by defect rearrangement consistent with simulations treating Skyrmions as point particles. Our findings underline the particle character of the Skyrmion.

Publisher's Note: Electronic Phase Separation and Dramatic Inverse Band Renormalization in the Mixed-Valence Cuprate LiCu_{2}O_{2} [Phys. Rev. Lett. 118, 176404 (2017)]

This corrects the article DOI: 10.1103/PhysRevLett.118.176404.

Electronic Phase Separation and Dramatic Inverse Band Renormalization in the Mixed-Valence Cuprate LiCu_{2}O_{2}

We measured, by angle-resolved photoemission spectroscopy, the electronic structure of LiCu_{2}O_{2}, a mixed-valence cuprate where planes of Cu(I) (3d^{10}) ions are sandwiched between layers containing one-dimensional edge-sharing Cu(II) (3d^{9}) chains. We find that the Cu(I)- and Cu(II)-derived electronic states form separate electronic subsystems, in spite of being coupled by bridging O ions. The valence band, of the Cu(I) character, disperses within the charge-transfer gap of the strongly correlated Cu(II) states, displaying an unprecedented 250% broadening of the bandwidth with respect to the predictions of density functional theory. Our observation is at odds with the widely accepted tenet of many-body theory that correlation effects generally yield narrower bands and larger electron masses and suggests that present-day electronic structure techniques provide an intrinsically inappropriate description of ligand-to-d hybridizations in late transition metal oxides.

Pregnancy outcome is influenced by luteal area during diestrus before successful insemination but not by milk production level

The objective was to compare luteal area (LA), luteal blood flow (LBF), and progesterone (P4) concentration before and after artificial insemination (AI) in pregnant and open cows in the diestrus preceding insemination and during the first 21 d after insemination. A number of 119 multiparous German Holstein cows were examined using B-mode and color Doppler sonography in diestrus (15-5 d before AI) and on days 7, 14, and 21 post insemination (pi). Blood samples for determination of P4 concentration were collected at each examination. In pregnant cows, P4 was measured in the diestrus before AI and on days 7, 14, and 21 of pregnancy, and in open cows, in the diestrus preceding the first AI and 7, 14, and 21 d later. Cows were retrospectively allocated into two groups according to the mean daily milk yield in the first 42 d (high milk yield [HMY], ≥39 kg/d; low milk yield [LMY], <39 kg/d). Pregnant cows had larger LA than open cows during diestrus before insemination (5.69 ± 1.85 vs. 4.94 ± 1.66 cm², P < 0.05), on days 7 (5.34 ± 1.83 vs. 4.52 ± 1.93 cm², P < 0.05) and 21 pi (5.92 ± 1.60 vs. 4.97 ± 1.44 cm², P < 0.05). On day 14 there was a tendency towards larger LA in pregnant cows (P = 0.09). Luteal blood flow (1.72 ± 0.74 vs. 1.22 ± 0.67 cm²) and P4 concentration (8.97 ± 4.37 vs. 6.49 ± 4.32 ng/mL) were higher in pregnant cows than in open cows on day 21 (P < 0.05). At day 150, 69% of the LMY cows and 56% of the HMY cows were pregnant (P > 0.05). Pregnant HMY cows had larger LA during diestrus before insemination and on days 7 and 21 pi than open HMY cows (P < 0.05) and tended to result in larger CLs on day 14 (P = 0.06). Pregnant HMY cows had higher LBF on days 14 and 21 (P < 0.05) and higher P4 concentration on day 21 than open HMY cows (P < 0.05). The main finding of this study was a larger LA during diestrus in cows that conceived in the ensuing estrous cycle compared to cows that did not conceive. Luteal area, LBF, and P4 concentration were greater in pregnant cows compared to open cows, and further studies should be conducted on the usefulness of these variables to detect open cows as early as possible after breeding. High-yielding cows appear to require larger LA, LBF, and higher P4 concentration than low-yielding cows to maintain pregnancy. In conclusion, larger LAs were established in pregnant cows in the diestrus before successful insemination regardless of their milk yield. Further studies are needed to verify whether LA in the diestrus before insemination might be used to predict probabilities in reproductive performance.

Pressure-induced superconductivity in the giant Rashba system BiTeI

At ambient pressure, BiTeI exhibits a giant Rashba splitting of the bulk electronic bands. At low pressures, BiTeI undergoes a transition from trivial insulator to topological insulator. At still higher pressures, two structural transitions are known to occur. We have carried out a series of electrical resistivity and AC magnetic susceptibility measurements on BiTeI at pressure up to  ∼40 GPa in an effort to characterize the properties of the high-pressure phases. A previous calculation found that the high-pressure orthorhombic P4/nmm structure BiTeI is a metal. We find that this structure is superconducting with T _c values as high as 6 K. AC magnetic susceptibility measurements support the bulk nature of the superconductivity. Using electronic structure and phonon calculations, we compute T _c and find that our data is consistent with phonon-mediated superconductivity.

Evidence for a Strong Topological Insulator Phase in ZrTe_{5}

The complex electronic properties of ZrTe_{5} have recently stimulated in-depth investigations that assigned this material to either a topological insulator or a 3D Dirac semimetal phase. Here we report a comprehensive experimental and theoretical study of both electronic and structural properties of ZrTe_{5}, revealing that the bulk material is a strong topological insulator (STI). By means of angle-resolved photoelectron spectroscopy, we identify at the top of the valence band both a surface and a bulk state. The dispersion of these bands is well captured by ab initio calculations for the STI case, for the specific interlayer distance measured in our x-ray diffraction study. Furthermore, these findings are supported by scanning tunneling spectroscopy revealing the metallic character of the sample surface, thus confirming the strong topological nature of ZrTe_{5}.