Influence of mismatch on the defects in relaxed epitaxial InGaAs/GaAs(100) films grown by molecular beam epitaxy

Thick (∼3 μm) films of InxGa1−xAs grown on GaAs(100) substrates, across the whole composition range, have been examined by transmission electron microscopy and double‐crystal x‐ray diffraction. The results were compared with the observed growth mode of the material determined by in situ reflection high‐energy electron diffraction in the molecular beam epitaxy growth system. The quality of the material degraded noticeably for compositions up to x∼0.5 associated with an increased density of dislocations and stacking faults. In contrast, improvements in quality as x approached 1.0 were correlated with the introduction of an increasingly more regular array of edge dislocations

Coping with systemic lupus erythematosus in patients' words

Objective Previous research on coping strategies of patients with SLE showed that there are no absolute adaptive or maladaptive strategies and that the range of potential coping strategies is large and heterogeneous. In this paper, we aimed to identify, in a large sample of patients with SLE (N=3222), the most frequent words used by patients to describe their coping strategies, to group them into significant themes and to test their possible association with specific patient characteristics. Methods Our analyses were based on the data set of the European survey 'Living with Lupus in 2020' (N=3222). Through the T-LAB software, we analysed the answers that adult participants gave to an open-ended question about how they cope with the disease. We identified the most frequent words, and with hierarchical cluster analysis we grouped them into semantic clusters (ie, themes) that were characterised by specific patterns of words. Finally, we tested the possible association between clusters and illustrative variables (sociodemographics, disease characteristics, quality of life). Results Five coping strategies were identified, each of them constituting an important percentage of the total word occurrences: positive attitude (22.58%), social support (25.46%), medical treatments (10.77%), healthy habits (20.74%) and avoid stress (20.45%). Each strategy was statistically associated with specific patient characteristics, such as age and organ involvement. Conclusions Learning to adapt to a lifetime of having SLE may require replacing old coping strategies with more effective ones. Investigating patients' coping strategies in relation to different patient characteristics represents a useful starting point for developing more targeted and efficacious interventions

Advanced waveform analysis of diaphragm surface EMG allows for continuous non-invasive assessment of respiratory effort in critically ill patients at different PEEP levels

Background: Respiratory effort should be closely monitored in mechanically ventilated ICU patients to avoid both overassistance and underassistance. Surface electromyography of the diaphragm (sEMGdi) offers a continuous and non-invasive modality to assess respiratory effort based on neuromuscular coupling (NMCdi). The sEMGdi derived electrical activity of the diaphragm (sEAdi) is prone to distortion by crosstalk from other muscles including the heart, hindering its widespread use in clinical practice. We developed an advanced analysis as well as quality criteria for sEAdi waveforms and investigated the effects of clinically relevant levels of PEEP on non-invasive NMCdi. Methods: NMCdi was derived by dividing end-expiratory occlusion pressure (Pocc) by sEAdi, based on three consecutive Pocc manoeuvres at four incremental (+ 2 cmH2O/step) PEEP levels in stable ICU patients on pressure support ventilation. Pocc and sEAdi quality was assessed by applying a novel, automated advanced signal analysis, based on tolerant and strict cut-off criteria, and excluding inadequate waveforms. The coefficient of variations (CoV) of NMCdi after basic manual and automated advanced quality assessment were evaluated, as well as the effect of an incremental PEEP trial on NMCdi. Results: 593 manoeuvres were obtained from 42 PEEP trials in 17 ICU patients. Waveform exclusion was primarily based on low sEAdi signal-to-noise ratio (Ntolerant = 155, 37%, Nstrict = 241, 51% waveforms excluded), irregular or abrupt cessation of Pocc (Ntolerant = 145, 35%, Nstrict = 145, 31%), and high sEAdi area under the baseline (Ntolerant = 94, 23%, Nstrict = 79, 17%). Strict automated assessment allowed to reduce CoV of NMCdi to 15% from 37% for basic quality assessment. As PEEP was increased, NMCdi decreased significantly by 4.9 percentage point per cmH2O. Conclusion: Advanced signal analysis of both Pocc and sEAdi greatly facilitates automated and well-defined identification of high-quality waveforms. In the critically ill, this approach allowed to demonstrate a dynamic NMCdi (Pocc/sEAdi) decrease upon PEEP increments, emphasising that sEAdi-based assessment of respiratory effort should be related to PEEP dependent diaphragm function. This novel, non-invasive methodology forms an important methodological foundation for more robust, continuous, and comprehensive assessment of respiratory effort at the bedside.</p

On QCD analysis of stucture function F2γF_2^{\gamma} in alternative approach

The alternative approach to QCD analysis of the photon structure function $F_2^{\gamma}$ is presented. It differs from the conventional one by the presence of the terms which in conventional approach appear in higher orders. We show that this difference concerns also the photonic parton distribution functions. In the alternative approach, the complete LO analysis of $F_2^{\gamma}$ can be performed as all required quantities are known. At the NLO, however, one of the coefficient function is so far not available and thus only the photonic parton distribution function can be computed and compared to those of standard approach. We discuss the numerical difference of these approaches at the LO and the NLO approximation and show that in case of $F_2^{\gamma}$ this difference is non-negligible and may play an important role in the analysis on photon data of the future experiments.Comment: 25 page

Skip Nav Destination RESEARCH ARTICLE| MARCH 16, 2022 Assessing the effect of melt extraction from mushy reservoirs on compositions of granitoids: From a global database to a single batholith

Mafic and ultramafic plutonic rocks are often considered to be crystal cumulates (i.e., they are melt-depleted), but such a classification is much more contentious for intermediate to silicic granitoids (e.g., tonalite, granodiorite, granite, and syenite). Whether or not a given plutonic rock has lost melt to feed shallower subvolcanic intrusive bodies or volcanic edifices has key implications for understanding igneous processes occurring within the crust throughout the evolution of the Earth. We use statistical analyses of a global volcanic and plutonic rock database to show that most mafic to felsic plutonic rock compositions can be interpreted as melt-depleted (i.e., most of the minerals analyzed are more evolved than their bulk-rock compositions would allow). To illustrate the application of the method to natural samples (from the Tertiary Adamello Batholith in the southern Alps), we estimate the degree of melt depletion using a combination of magmatic textures, bulk-rock chemistry, modal mineralogy, distributions of plagioclase composition (using scanning electron microscope phase mapping/electron microprobe analyses), and thermodynamic modeling. We find that melt depletion correlates with the magmatic foliation and is accompanied by bulk depletion in incompatible elements, low amounts of near-solidus minerals, and mineral compositions that are too evolved (i.e., depleted in Ca or Mg, depending on the mineral) to be in equilibrium with their bulk-rock chemistry. The analytical and modeling workflow proposed in this study provides a path to quantifying melt depletion in any plutonic samples

Resonant Production of Scalar Diquarks at the Next Generation Electron-Positron Colliders

We investigate the potential of TESLA and JLC/NLC electron-positron linear collider designs to observe diquarks produced resonantly in processes involving hard photons.Comment: 14 pages, 8 figures, coded in RevTEX, uses epsfi

A Transfer Hamiltonian Model for Devices Based on Quantum Dot Arrays

We present a model of electron transport through a random distribution of interacting quantum dots embedded in a dielectric matrix to simulate realistic devices. The method underlying the model depends only on fundamental parameters of the system and it is based on the Transfer Hamiltonian approach. A set of noncoherent rate equations can be written and the interaction between the quantum dots and between the quantum dots and the electrodes is introduced by transition rates and capacitive couplings. A realistic modelization of the capacitive couplings, the transmission coefficients, the electron/hole tunneling currents, and the density of states of each quantum dot have been taken into account. The effects of the local potential are computed within the selfconsistent field regime. While the description of the theoretical framework is kept as general as possible, two specific prototypical devices, an arbitrary array of quantum dots embedded in a matrix insulator and a transistor device based on quantum dots, are used to illustrate the kind of unique insight that numerical simulations based on the theory are able to provide