Full Picture of Lattice Deformation in a GeSn Micro-Disk by 5D X-ray Diffraction Microscopy.

Lattice strain in crystals can be exploited to effectively tune their physical properties. In microscopic structures, experimental access to the full strain tensor with spatial resolution at the (sub-)micrometer scale is at the same time very interesting and challenging. In this work, how scanning X-ray diffraction microscopy, an emerging model-free method based on synchrotron radiation, can shed light on the complex, anisotropic deformation landscape within three dimensional (3D) microstructures is shown.

Strain in Hybrid Organic-Inorganic Metal Halide Perovskites Microstructures by Numerical Simulations.

Hybrid organic-inorganic metal halide perovskites (HOIPs) are promising materials for optoelectronics applications. Their optical and electrical properties can be controlled by strain engineering, that results from application of local elastic deformation or deposition on pre-patterned substrates acquiring a conformal 3D shape. Most interesting, their mechanical properties depend on their crystal structure, composition and dimensionality.

Nanoscale Mapping of the 3D Strain Tensor in a Germanium Quantum Well Hosting a Functional Spin Qubit Device.

A strained Ge quantum well, grown on a SiGe/Si virtual substrate and hosting two electrostatically defined hole spin qubits, is nondestructively investigated by synchrotron-based scanning X-ray diffraction microscopy to determine all its Bravais lattice parameters. This allows rendering the three-dimensional spatial dependence of the six strain tensor components with a lateral resolution of approximately 50 nm. Two different spatial scales governing the strain field fluctuations in proximity of the qubits are observed at <100 nm and >1 μm, respectively.

Tailoring Photoluminescence by Strain-Engineering in Layered Perovskite Flakes.

Strain is an effective strategy to modulate the optoelectronic properties of 2D materials, but it has been almost unexplored in layered hybrid organic-inorganic metal halide perovskites (HOIPs) due to their complex band structure and mechanical properties. Here, we investigate the temperature-dependent microphotoluminescence (PL) of 2D (CHCHCHNH)CsPbBr HOIP subject to biaxial strain induced by a SiO ring platform on which flakes are placed by viscoelastic stamping. At 80 K, we found that a strain of <1% can change the PL emission from a single peak (unstrained) to three well-resolved peaks.

n-type Ge/Si antennas for THz sensing.

Ge-on-Si plasmonics holds the promise for compact and low-cost solutions in the manipulation of THz radiation. We discuss here the plasmonic properties of doped Ge bow-tie antennas made with a low-point cost CMOS mainstream technology. These antennas display resonances between 500 and 700 GHz, probed by THz time domain spectroscopy.

Acute Kidney Injury and COVID-19: A Picture from an Intensive Care Unit.

Introduction: Acute kidney injury (AKI) is a frequent complication in coronavirus disease 2019 (COVID-19) patients admitted to intensive care unit (ICU) for severe respiratory failure. The aim is to evaluate the rate of AKI, defined according to Kidney Disease: Improving Global Outcome guidelines, in a series of critical COVID-19 patients admitted to the ICU of a single tertiary teaching hospital.

Methods: From April to May 2020, all consecutive critically ill COVID-19 patients admitted to the ICU who did not meet exclusion criteria (length of ICU stay <48 h, ESRD requiring dialysis, and patients still hospitalized in ICU at the time of data analysis) were enrolled in this study.

Ge(Sn) nano-island/Si heterostructure photodetectors with plasmonic antennas.

We report on photodetection in deep subwavelength Ge(Sn) nano-islands on Si nano-pillar substrates, in which self-aligned nano-antennas in the Al contact metal are used to enhance light absorption by means of local surface plasmon resonances. The impact of parameters such as substrate doping and device geometry on the measured responsivities are investigated and our experimental results are supported by simulations of the three-dimensional distribution of the electromagnetic fields. Comparatively high optical responsivities of about 0.

Correlation of Optical, Structural, and Compositional Properties with V-Pit Distribution in InGaN/GaN Multiquantum Wells.

InGaN/GaN double heterostructures and multiquantum wells (MQWs) have been successfully developed since more than 20 years for LED lightning applications. Recent developments show that state-of-the-art LEDs benefit from artificially generated V-pit defects. However, the control of structural and chemical properties plays a tremendous role.

Heterogeneous integration of lithium niobate and silicon nitride waveguides for wafer-scale photonic integrated circuits on silicon.

An ideal photonic integrated circuit for nonlinear photonic applications requires high optical nonlinearities and low loss. This work demonstrates a heterogeneous platform by bonding lithium niobate (LN) thin films onto a silicon nitride (SiN) waveguide layer on silicon. It not only provides large second- and third-order nonlinear coefficients, but also shows low propagation loss in both the SiN and the LN-SiN waveguides.

Influence of aqueous humor convection current on IOL opacification.

Background And Purpose: The opacification of Akreos Adapt (Bausch & Lomb, Rochester; NY) intraocular lens (IOL) has been previously reported in Literature. A metabolic change in aqueous humour was considered as the main trigger factor to IOL opacification. We report our case and discuss the association with Ex-PRESS, highlighting the particular pattern of IOL opacification and its possible relation with the intraocular convective motions of the aqueous.

Silicon photonic waveguide metrology using Mach-Zehnder interferometers.

We propose a procedure for characterizing fabrication deviations within a chip and among different chips in a wafer in silicon photonics technology. In particular, independent measurements of SOI thickness and waveguide width deviations can be mapped through the wafer, allowing a precise and non-destructive characterization of how these variations are distributed along the surface of the wafer. These deviations are critical for most wavelength-dependent integrated devices, like microring resonators, filters, etc.

Modeling of strain-induced Pockels effect in Silicon.

We propose a theoretical model to describe the strain-induced linear electro-optic (Pockels) effect in centro-symmetric crystals. The general formulation is presented and the specific case of the strained silicon is investigated in detail because of its attractive properties for integrated optics. The outcome of this analysis is a linear relation between the second order susceptibility tensor and the strain gradient tensor, depending generically on fifteen coefficients.

Systemic complications of esophageal lichen planus.

Lichen planus is an uncommon inflammatory mucocutaneous disorder affecting the skin and its appendages, as well as oral and genital mucosa. Involvement of the esophageal mucosa is rare and causes significant morbidity, with dysphagia and risk of long-term complications, such as esophageal strictures and stenosis. Esophageal lichen planus is an underreported condition in the spectrum of lichenoid tissue reactions, presenting the risk of systemic manifestations.

Ophthalmological aspects of IBD.

Ocular manifestations occur in 4-12% of patients with IBD. Uveitis and iritis are more frequently associated with ulcerative colitis while episcleritis is more common in Crohn's disease. Some ocular manifestations in IBD can be secondary to treatment and/or effects of the intestinal disease itself.

Efficacy of etanercept in the treatment of a patient with Behçet's disease.

Behçet's disease is a systemic inflammatory disorder without a specific treatment that is chosen on the basis of the type and severity of manifestation in the organ involved. More recently, biological agents like etanercept have emerged as possible therapeutic alternatives in patients resistant to conventional therapy. We describe the successful treatment for 1 year of resistant Behçet's disease with etanercept.

Retinal function following transpupillary thermotherapy for occult choroidal neovascularization in age-related macular degeneration: a short-term study by focal electroretinography.

Purpose: To assess short-term changes in macular function after transpupillary thermotherapy (TTT) in patients with occult subfoveal choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD), using focal electroretinography (FERG).

Methods: Twenty-five patients with occult subfoveal CNV due to AMD were treated with TTT delivered using an infrared (810 nm) diode laser (spot size 3.0 mm, laser power 400-600 mW, duration 60 seconds).

Vestibular evaluation in Behçet's disease. Personal experience.

Few reports have appeared in the literature concerning vestibular findings in Behçet's disease. In the present study, extensive vestibular testing, performed in 14 patients (8 male, 6 female; mean age: 32 years; range: 12-51) presenting definite Behçet's disease, revealed a high prevalence of central vestibular dysfunctions (78%). Data reported here suggest that an otoneurological evaluation of Behçet's disease patients may be helpful in identifying unexpected vestibular dysfunctions and central nervous system involvement different from the classical manifestations of the neuro-Behçet's syndrome.

Monitoring retinal function during transpupillary thermotherapy for occult choroidal neovascularization in age-related macular degeneration.

Purpose: To use focal electroretinography to evaluate changes in retinal function during transpupillary thermotherapy (TTT) for neovascular age-related macular degeneration (ARMD).

Methods: Sixteen eyes of 16 patients with ARMD with occult choroidal neovascularization (CNV) were studied. A 630-nm photocoagulator aiming beam was modified for use as a 41-Hz square-wave focal electroretinogram (fERG) stimulus.