Burden of hidradenitis suppurativa: a systematic literature review of patient reported outcomes

Introduction Hidradenitis suppurativa (HS) has a profound negative impact on patients’ health-related quality of life (HRQoL). Here we summarize the evidence on HRQoL and Patient Reported Outcomes (PROs) in patients with HS in real-world settings by conducting a systematic literature review (SLR) of observational studies. Methods Data sources included MEDLINE, Embase & PsycINFO between January 1, 2010 and August 29, 2021, and conference proceedings between 2019 and 2021. Identified abstracts were reviewed and screened independently by two reviewers. Eligibility criteria included patients with HS of any severity, sample size ≥ 100, reporting PROs including HRQoL measures. Included studies were critically appraised. Results Fifty-eight observational studies matched inclusion criteria. Dermatology Life Quality Index (DLQI) was the most commonly utilized instrument: 57% of included studies reported mean baseline DLQI scores, ranging between 8.4 and 16.9, indicating a very large impact on the patients’ HRQoL. Higher scores were reported with increasing disease severity and among female patients. Pain was assessed mostly by an 11-point (0–10) numeric rating scale (NRS) with a mean baseline score ranging from 3.6 to 7.7 indicating moderate to high pain levels. There was a negative impact of HS on patients’ psychological well-being, based on PRO scores related to depression and anxiety. A high proportion of sexual dysfunction was reported, with a larger impact on women than men. Work productivity and leisure activity were consistently found to be impaired in patients with HS. Conclusions All included studies reported a negative impact of HS on patients’ lives. A diverse set of disease- and non-disease-specific PRO instruments were utilized highlighting the need for more consistent use of HS-specific validated PRO instruments to assess the impact of HS on the different aspects of patients’ HRQoL to allow for data to be more meaningfully interpreted and compared in real-world settings. Patients with HS need better disease management approaches that address the observed low quality of life

Impact of vertical inter-QDs spacing correlation with the strain energy in a coupled bilayer quantum dot heterostructure

This study investigates the vertical inter-QDs spacing (VIDS) in a coupled bilayer quantum dots (CBQD) heterostructure using cross-sectional High Resolution Transmission Electron Microscopy (HRTEM). Simultaneously, we also examined the interrelationship of VIDS with the strain energy inside the CBQD stack. As a continuation, the CBQD heterostructure were further explored from different aspects of growth parameters, such as the deposition of ultrathin GaAs spacer layer of 4.0-4.5 nm between the seed and active layer of QDs, the effect of larger monolayer coverage (3.2 ML) of seed layer QDs, and the optimization of growth rates for the CBQDs. Moreover, we present a model technique to characterize the in-plane 2 theta chi/Phi of InAs QDs and GaAs at (002) and (004) planes in order to analyze the strain. This study was the first of its kind to look at the formation of self-assembled In-(x) Ga(1-x) As layer at the interface across the ultrathin GaAs spacer and InAs QDs, verified with HRTEM images. Smaller size of QDs formed in the seed layer led to the formation of a non-uniform self-assembled In-(x) Ga(1-x) As layer. The problem of non-uniformity of In-(x) Ga(1-x) As layer was resolved by increasing the seed layer monolayer coverage from 2.5 to 3.2 ML. The percentage of gallium adatoms inter-diffused into the outer surface of InAs QDs to form the self-assembled In-(x) Ga(1-x) As layer was similar to 31% for VIDS similar to 1.4 +/- 2 nm. (C) 2017 Elsevier B.V. All rights reserved

The impact of confinement enhancement AlGaAs barrier on the optical and structural properties of InAs/InGaAs/GaAs submonolayer quantum dot heterostructures

The effect of additional AlxGa1-xAs barrier layer on luminescence and structural behaviors of four cycle InAs/In0.15Ga0.85As/GaAs based quantum dots (i.e., standard submonolayer (SML) QDs) has been investigated here. Blue-shift in peak emission wavelength, along with narrow full width at half maxima (FWHM) is observed, as evidenced by the photoluminescence measurement results. InAs SML QDs in an In0.15Ga0.85As/GaAs well with a confinement enhancing Al0.2Ga0.8As barrier exhibits the lowest FWHM of 10.12 meV with an activation energy of 110 meV. Cross-sectional transmission electron microscopy confirms improvement in QD size distribution and the presence of small QDs of high crystalline quality. Symmetric rocking curves along the [004] Bragg angle affirm that incorporation of the additional barrier improvs the crystalline quality of corresponding heterostructures and yields sharp interfaces with adequate amount of QDs. In addition, the ex situ annealing study exhibits the enhancement in thermal stability of optical properties through integration of this symmetric AlGaAs barrier

Evidence of quantum dot size uniformity in strain-coupled multilayered In (Ga)As/GaAs QDs grown with constant overgrowth percentage

Strain coupled multi-layer quantum dot (QD) structures are limited due to their non-uniform dot size distribution, as-grown defects and dislocations. Even with these limitations, they are subject of interest because of high optical and device efficiency. In this work, we propose a modified growth strategy in which monolayer (ML) deposition of QDs is varied based on reflection high energy electron diffraction (RHEED) pattern to achieve defect free structure with uniform dot size distribution. The overgrowth percentage, i.e. monolayer deposition above critical thickness (minimum thickness required for transition from two-dimensional (2D) to three-dimensional (3D) confined structures) was kept constant in modified strategy. To verify this claim, we have compared it with conventional strain coupled multilayer structure and demonstrated improved optical performance and device characteristics. Photoluminescence spectroscopy exhibited monomodal QD distribution in strain-coupled multi-stacked heterostructure grown by the proposed strategy. Power dependent photoluminescence (PL) measurement confirms existence of single ground state peak. The proposed strategy yielded a defect free structure and better carrier capture rate compared to conventional multilayer QDs. The spectral response observed from proposed quantum dot infrared photodetector (QDIP) exhibited multiple peaks in mid-IR region (3.92 mu m and 4.54 mu m), which is one of the essential requirements for fabricating infrared detectors or focal plane arrays. Post-growth thermal annealing treatment at various temperatures (650-800 degrees C) were performed to verify the change in activation energy, ground-state emission peak, and thermal stability. Negligible change in the ground-state PL emission peak (< 2%) and thermal activation energy (< 2%) were observed up to 750 degrees C. The full width at half maximum (FWHM) values of the ground-state peak of the annealed samples exhibited a similar trend. High-temperature thermal stability was achieved probably due to high strain field hindering material interdiffusion and improved quantum confinement realized from uniform QD sizes. The modified growth strategy used in this paper is helpful not only for improved optical characteristics, but also for useful device performances, such as a night vision camera in defense areas, cancer detector in medical applications and fabrication of thermal imagers; focal plane arrays

Optimization of hybrid InAs stranski krastanov and submonolayer quantum dot heterostructures and its effect on photovoltaic energy conversion efficiency in near infrared region

We are introducing here hybrid Stranski Krastanov (SK) on submonolayer (SML) quantum dot (QD) heterostructure for improved photovoltaic energy conversion in the near infrared (NIR) region. Vertically coupled QDs with lower amount of cumulative strain make it a promising competitor of homogeneous QD families. Still now no research groups have reported such heterogeneously coupled QD based quantum dot solar cell (QDSC) for better NIR harvesting. In the present study, we are emphasizing on growth optimization of such heterogeneous QD family. Ex situ modulation of interdot electronic interaction has been explored by rapid thermal annealing (RTA). The sample with 0.1 ML/s growth rate and 7.5 nm GaAs barrier comes out as the best coupled configuration with improved thermal stability. This particular configuration is incorporated into a P-I-N QDSC, which shows broader and enhanced external quantum efficiency at NIR region. In addition, RTA at 650 and 700 degrees C shows a drastic enhancement of quantum efficiency due to the annihilation of as grown defects and trap centers

High nitrogen composition-induced low interfacial roughness of GaAs0.978N0.022/GaAs multiple quantum wells grown through solid-source molecular beam epitaxy

GaAs1-xNx/GaAs multiple quantum wells (MQWs) were grown on GaAs(001) substrates through solid source molecular beam epitaxy under various nitrogen background pressures (NBPs), and the crystal quality at the interface of GaAs1-xNx and GaAs was investigated. X-ray diffraction and electron microscopy confirmed the low interface roughness of MQWs grown at a NBP of 5 x 10(-6) Torr. Surface morphology measurements revealed a smooth surface without whisker-like defect structures. The fabricated MQWs exhibited high photoluminescence intensity because of the reduction in surface recombination with high nitrogen incorporation. Raman spectroscopy confirmed the presence of N-like local vibrational mode, and this was attributed to the presence of phase separation in GaAsN alloys. Rapid thermal annealing improved photoluminescence intensity by 100-fold and substantially reduced full width at half maximum because of MQW homogenization. These results evidence the favorable crystal interface of GaAs0.978Na0.022 alloys. Hence, GaAs0.978N0.022/GaAs MQWs grown under high pressure might be useful in fabricating optoelectronic devices. (C) 2016 Published by Elsevier Ltd

Ultranarrow spectral response of InGaAs QDIPs through the optimization of strain-coupled stacks and capping layer composition

The effect of the capping layer and the number of strain-coupled stacks on the optoelectrical properties of In0.5Ga0.5As quantum dot infrared photodetectors (QDIPs) are reported in this paper. GaAs-capped and InGaAs-capped bilayer, trilayer, pentalayer, and heptalayer QDIPs were grown for the first time and analyzed. The ground-state photoluminescence emission of all coupled QDIPs redshifted relative to that of the uncoupled QDIPs. All coupled InGaAs-capped QDIPs exhibited monomodal spectral response, whereas among GaAs capped QDIPs, only the bilayer QDIP exhibited monomodal response. The optimal activation energy (339.87 meV) and full width at half maximum (FWHM; 16 meV) as well as the lowest dark current density (6.5E-8 A/cm(2)) at 100 K, and -1 V bias were observed for the InGaAs-capped trilayer QDIP among all due to better dot confinement, homogeneity, and also better strain coupling between the vertically stacks QD layers. The peak spectral response at 7.08 mu m obtained from this QDIP had an ultranarrow FWHM of 8.67 meV, making it useful for hyperspectral applications in the infrared region