Coulomb enhancement of high harmonic generation in monolayer transition metal dichalcogenides.

High harmonic generation (HHG) in monolayer MoS is studied using fully microscopic many-body models based on the semiconductor Bloch equations and density functional theory. It is shown that Coulomb correlations lead to a dramatic enhancement of HHG. In particular, near the bandgap, enhancements of two orders of magnitude or more are observed for a wide range of excitation wavelengths and intensities.

On the importance of electron-electron and electron-phonon scatterings and energy renormalizations during carrier relaxation in monolayer transition-metal dichalcogenides.

Anbased fully microscopic many-body approach is used to study the carrier relaxation dynamics in monolayer transition-metal dichalcogenides. Bandstructures and wavefunctions as well as phonon energies and coupling matrix elements are calculated using density functional theory. The resulting dipole and Coulomb matrix elements are implemented in the Dirac-Bloch equations to calculate carrier-carrier and carrier-phonon scatterings throughout the whole Brillouin zone (BZ).

Propagation Induced Dephasing in Semiconductor High-Harmonic Generation.

The influence of propagation on the nonperturbative high-harmonic features in long-wavelength strong pulse excited semiconductors is studied using a fully microscopic approach. For sample lengths exceeding the wavelength of the exciting light, it is shown that the propagation effectively acts as a very strong additional dephasing that reduces the relative height of the emission plateau up to six orders of magnitude. This propagation induced dephasing clarifies the need to use extremely short polarization decay times for the quantitative analysis of experimental observations.

Prehospital Administration of Unfractionated Heparin in ST-Segment Elevation Myocardial Infarction Is Associated With Improved Long-Term Survival.

Objective: Administration of unfractionated heparin to STEMI patients by the ambulance service is an established practice in Scotland, but the efficacy is unknown. We studied the effects of unfractionated heparin in STEMI patients treated by primary percutaneous coronary intervention, on infarct artery patency and mortality.

Methods And Results: Consecutive patients (n = 1000) admitted to Ninewells Hospital, Dundee, from 2010 to 2014 for primary percutaneous coronary intervention were allocated to 2 groups: 437 (44%) prehospital heparin (PHH) administered by paramedics, and 563 (56%) in-hospital heparin.

Two-stage filamentation of 10 μm pulses as a broadband infrared backlighter in the atmosphere.

We identify a two-stage filamentation regime for high-power 10 μm multipicosecond pulses propagating in the atmosphere. The first low-intensity stage is mainly regularized by ionization through excitation induced dephasing, which can lead to strong pulse shortening downstream. This shortening in turn causes a significant reduction of the many-body induced plasma, which changes the dynamics drastically.

Failure of an expandable cage-plate cervical vertebral body replacement: case report of a device related complication.

Instabilities of the cervical spine after complete or incomplete corpectomy may be the result from resection due to stenosis induced myelopathy, tumors, infections or fractures. In this article, we report a 49-year-old female patient after surgical decompression and stabilization at C5/7 with permanent cervicobrachialgia due to cervical stenosis at C5/7. Corpectomy of C6 and stabilization of C5/7 were performed with a combination of cage and plate.

Multi-terawatt 10 μm pulse atmospheric delivery over multiple Rayleigh ranges.

We predict that long wavelength self-trapped multi-terawatt pulses can be sustained over multiple kilometers in the atmosphere. Unlike filaments, these pulses exhibit low loss propagation and retain most of their launch power at range. A novel mechanism involving an aggregation of weakly linear and nonlinear cumulative optical responses is shown to be responsible and is dominated by an ultrafast dynamical lensing resulting from a field intensity driven many-body Coulomb mediated free electron polarization associated with spatially separated species in the gas.

Internal and External Temperature Monitoring of a Li-Ion Battery with Fiber Bragg Grating Sensors.

The integration of fiber Bragg grating (FBG) sensors in lithium-ion cells for in-situ and in-operando temperature monitoring is presented herein. The measuring of internal and external temperature variations was performed through four FBG sensors during galvanostatic cycling at C-rates ranging from 1C to 8C. The FBG sensors were placed both outside and inside the cell, located in the center of the electrochemically active area and at the tab-electrode connection.

A highly efficient directional molecular white-light emitter driven by a continuous-wave laser diode.

Tailored light sources have greatly advanced technological and scientific progress by optimizing the emission spectrum or color and the emission characteristics. We demonstrate an efficient spectrally broadband and highly directional warm-white-light emitter based on a nonlinear process driven by a cheap, low-power continuous-wave infrared laser diode. The nonlinear medium is a specially designed amorphous material composed of symmetry-free, diamondoid-like cluster molecules that are readily obtained from ubiquitous resources.

In situ probing of mode-locked vertical-external-cavity-surface-emitting lasers.

We utilize an asynchronous optical sampling technique to study the gain dynamics of vertical-external-cavity-surface-emitting lasers (VECSELs) under mode-locked operation. This allows for an in situ characterization of the gain depletion and recovery over nanoseconds with femtosecond-scale resolution. Our method allows for a more direct study of intracavity gain dynamics than traditional pump/probe measurements.

Strong Impact of Smoking on Multimorbidity and Cardiovascular Risk Among Human Immunodeficiency Virus-Infected Individuals in Comparison With the General Population.

Background.  Although acquired immune deficiency syndrome-associated morbidity has diminished due to excellent viral control, multimorbidity may be increasing among human immunodeficiency virus (HIV)-infected persons compared with the general population. Methods.

Homogeneous lithium electrodeposition with pyrrolidinium-based ionic liquid electrolytes.

In this study, we report on the electroplating and stripping of lithium in two ionic liquid (IL) based electrolytes, namely N-butyl-N-methylpyrrolidinium bis(fluorosulfonyl) imide (Pyr14FSI) and N-butyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (Pyr14TFSI), and mixtures thereof, both on nickel and lithium electrodes. An improved method to evaluate the Li cycling efficiency confirmed that homogeneous electroplating (and stripping) of Li is possible with TFSI-based ILs. Moreover, the presence of native surface features on lithium, directly observable via scanning electron microscope imaging, was used to demonstrate the enhanced electrolyte interphase (SEI)-forming ability, that is, fast cathodic reactivity of this class of electrolytes and the suppressed dendrite growth.

Evolution of multi-mode operation in vertical-external-cavity surface-emitting lasers.

The longitudinal multi-mode emission in a vertical-external-cavity surface-emitting laser is investigated using both single shot streak camera measurements and interferometric measurement techniques. For this, the laser is operated in the single- and two-color emission regime using both an etalon and a free-running configuration without etalon, respectively. The laser emission is analyzed with respect to pump power and output coupling losses for a long and for a short resonator.

Narrow linewidth single-frequency terahertz source based on difference frequency generation of vertical-external-cavity source-emitting lasers in an external resonance cavity.

We demonstrate a continuous wave, single-frequency terahertz (THz) source emitting 1.9 THz. The linewidth is less than 100 kHz and the generated THz output power exceeds 100 μW.

Grating-based wavelength control of single- and two-color vertical-external-cavity-surface-emitting lasers.

Wide wavelength tunability of single- and two-color operating vertical-external-cavity-surface-emitting lasers (VECSELs) is demonstrated. Employing an external feedback based on a diffractive grating outside the cavity of a narrow-line single-color VECSEL allows for a continuous tuning of the emission wavelength over 10 nm. Employing a dual-feedback-configuration for tunable two-color emission, a tunability of the difference frequency between the two lasing wavelengths from 300 gigahertz to up to 3.

Mixed oxide coatings for optics.

Material mixtures offer new possibilities for synthesizing coating materials with tailored optical and mechanical properties. We present experimental results on mixtures of HfO2, ZrO2, and Al2O3, pursuing applications in UV coating technology, while the mixtures are prepared by magnetron sputtering, ion beam sputtering, plasma ion-assisted deposition (PIAD), and electron beam evaporation without assistance. The properties investigated include the refractive index, optical gap, thermal shift, and mechanical stress.

Room temperature continuous wave milliwatt terahertz source.

We present a continuous wave terahertz source based on intracavity difference frequency generation within a dual color vertical external cavity surface emitting laser. Using a nonlinear crystal with a surface emitting phase matching scheme allows for high conversion efficiencies. Due to the tunability of the dual mode spacing, the entire spectral range of the terahertz gap can be covered.

Continuous-wave single-frequency 295 nm laser source by a frequency-quadrupled optically pumped semiconductor laser.

Up to 136 mW of cw single-frequency output at 295 nm was obtained from a frequency-quadrupled optically pumped semiconductor laser. The highly strained InGaAs quantum-well semiconductor laser operates at 1178 nm in a single frequency. The single-frequency intracavity-doubled 589 nm output is further converted to 295 nm in an external resonator using beta-BaB(2)O(4).

Multichip vertical-external-cavity surface-emitting lasers: a coherent power scaling scheme.

We propose an efficient coherent power scaling scheme, the multichip vertical-external-cavity surface-emitting laser (VECSEL), in which the waste heat generated in the active region is distributed on multi-VECSEL chips such that the pump level at the thermal rollover is significantly increased. The advantages of this laser are discussed, and the development and demonstration of a two-chip VECSEL operating around 970 nm with over 19 W of output power is presented.

Closed-loop design of a semiconductor laser.

We provide what we believe is the first closed-loop prediction of a semiconductor laser performance using fully microscopic many-body models for the spontaneous emission, gain, and carrier recombination losses due to Auger processes without having to resort to phenomenological adjustable fit parameters.

Transition between different coherent light-matter interaction regimes analyzed by phase-resolved pulse propagation.

We present phase-resolved pulse propagation measurements that allow us to fully describe the transition between several light-matter interaction regimes. The complete range from linear excitation to the breakdown of the photonic bandgap on to self-induced transmission and self-phase modulation is studied on a high-quality multiple-quantum-well Bragg structure. An improved fast-scanning cross-correlation frequency-resolved optical gating setup is applied to retrieve the pulse phase with an excellent signal-to-noise ratio.

Healing of osteochondral grafts in an ovine model under the influence of bFGF.

Purpose: The well-recognized limitations in cartilage healing have lead to the development of a number of resurfacing techniques for defects of joint surfaces. Autologous grafting has developed into 1 of the preferred methods of treatment for focal osteochondral lesions, although basic research on this topic remains sparse.

Type Of Study: In an animal study, questions regarding the healing of osteochondral transplants under the influence of basic fibroblast growth factor (bFGF) were addressed.