Band structure by design in 2D layered semiconductors is highly desirable, with the goal to acquire the electronic properties of interest through the engineering of chemical composition, structure, ...defect, stacking, or doping. For atomically thin transition metal dichalcogenides, substitutional doping with more than one single type of transition metals is the task for which no feasible approach is proposed. Here, the growth of WS2 monolayer is shown codoped with multiple kinds of transition metal impurities via chemical vapor deposition controlled in a diffusion‐limited mode. Multielement embedment of Cr, Fe, Nb, and Mo into the host lattice is exemplified. Abundant impurity states thus generate in the bandgap of the resultant WS2 and provide a robust switch of charging/discharging states upon sweep of an electric filed. A profound memory window exists in the transfer curves of doped WS2 field‐effect transistors, forming the basis of binary states for robust nonvolatile memory. The doping technique presented in this work brings one step closer to the rational design of 2D semiconductors with desired electronic properties.
Multielement codoped monolayer WS2 is synthesized using chemical vapor deposition. No dopant clustering and phase segregation occur and WS2 retains n‐type semiconducting properties. Substantial and stable impurities states are introduced near the conduction band minimum. Through the charging/discharging of the impurity states, the doped WS2 functions as a nonvolatile memory with long charge‐retention time.
Obstructive sleep apnea (OSA) can cause sleep fragmentation and intermittent hypoxemia, which are linked to oxidative stress. White matter changes (WMCs) representing cerebrovascular burden and are ...at risk factor for oxidative ischemic injury. The current study explores the mutual relationships between OSA and WMCs. We performed a systematic review of electronic databases for clinical studies investigating OSA and WMCs. Random-effects models were used for pooled estimates calculation. A total of 22 studies were included in the meta-analysis. The results revealed a significantly higher prevalence rate of WMCs odds ratio (OR) 2.06, 95% confidence interval (CI) 1.52–2.80,
p
< 0.001 and significantly higher severity of WMCs (Hedges’
g
= 0.23, 95% CI 0.06–0.40,
p
= 0.009) in the patients with OSA than in controls. Furthermore, the results revealed a significantly higher apnea–hypopnea index (Hedges’
g
= 0.54, 95% CI 0.31–0.78,
p
< 0.001) and significantly higher prevalence rate of moderate-to-severe OSA (OR 2.86, 95% CI 1.44–5.66,
p
= 0.003) in the patients with WMCs than in controls, however there was no significant difference in the prevalence rate of mild OSA between the patients with WMCs and controls (OR 0.71, 95% CI 0.20–2.54,
p
= 0.603). OSA was associated with a higher prevalence and more severe WMCs, and the patients with WMCs had an increased association with moderate-to-severe OSA. Future large-scale randomized controlled trials with a longitudinal design are essential to further evaluate treatment in patients with OSA.
In this letter, we report on the fabrication and photovoltaic characteristics of p-i-n GaN/InGaN thin-film solar cells. The thin-film solar cells were fabricated by removing sapphire using a laser ...lift-off technique and, then, transferring the remaining p-i-n structure onto a Ti/Ag mirror-coated Si substrate via wafer bonding. The mirror structure is helpful to enhance light absorption for a solar cell with a thin absorption layer. After the thin-film process for a conventional sapphire-based p-i-n solar cell, the device exhibits an enhancement factor of 57.6% in current density and an increment in conversion efficiency from 0.55% to 0.80%. The physical origin for the photocurrent enhancement in the thin-film solar cell is related to multireflection of light by the mirror structure.
A vision-based adaptive switching controller that uses optical flow information to avoid obstacles for micro unmanned aerial vehicles (MUAV) is proposed in this paper. To use the optical flow to ...indicate the distance between the MUAV and the environment, we propose an algorithm with multi-thread processing such that the optical flow information is obtained reliably and continuously in the entire camera field of view. The flying behavior of considered MUAV is regarded as a switching system when considering different flying modes during the mission of obstacle avoidance. By the required flight direction for obstacle avoidance specified by the detected optical flow, an adaptive control scheme is designed to track the required trajectory in switching modes. The simulation result shows the tracking performances of the adaptive control with the switching system. The experiment of the whole system is completed to verify the obstacle avoidance capability of our system.
In this letter, InGaN-based solar cells with a p-InGaN/i-InGaN/n-GaN double-heterojunction structure were fabricated and characterized. Two kinds of sapphire substrates i.e., a conventional sapphire ...substrate (CSS) and a patterned sapphire substrate (PSS) were used for epitaxial growth. Both the solar cells grown on the CSS and the PSS demonstrated a high open-circuit voltage of 2.05 and 2.08 V, respectively. However, the short-circuit current of the solar cells grown on the PSS showed an improvement of 27.6% compared with that of the cells grown on the CSS. Such observation could be attributed to low edge-dislocation density and the increase in the light-absorption path by the scattering of interface incident light between the substrate and the epitaxial layer for the solar cell grown on the PSS.
The atomic-scale homogenization of a face-centered-cubic-based high-entropy alloy (HEA), Al0.3Cu0.5CoCrFeNi, using severe plastic deformation (SPD) is reported. Atom probe tomography revealed that ...water quenching from high temperature cannot produce a homogeneous single phase, and clustering of Cu, Al and Ni still exists. Subsequent processing by high-pressure torsion produced nanostructured non-equilibrium single phase with homogeneous elemental distribution at atomic scale. Importantly, such a non-equilibrium single phase is stable at room temperature due to the sluggish diffusion kinetics. These observations suggest that SPD is an effective approach for producing single-phase HEAs for fundamental studies and applications.
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•Conventional heat treatment cannot eliminate clustering in Al0.3Cu0.5CoCrFeNi HEA.•HPT enhances intermixing of elements in this multicomponent alloy.•Principal elements show nearly ideal random distribution at atomic scale after HPT.•Slow diffusion kinetics keeps the non-equilibrium alloy stable at room temperature.
Whether preoperative proteinuria associates with adverse renal outcomes after cardiac surgery is unknown. Here, we performed a secondary analysis of a prospectively enrolled cohort of adult patients ...undergoing coronary artery bypass grafting (CABG) at a medical center and its two affiliate hospitals between 2003 and 2007. We excluded patients with stage 5 CKD or those who received dialysis previously. We defined proteinuria, measured with a dipstick, as mild (trace to 1+) or heavy (2+ to 4+). Among a total of 1052 patients, cardiac surgery-associated acute kidney injury (CSA-AKI) developed in 183 (17.4%) patients and required renal replacement therapy (RRT) in 50 (4.8%) patients. In a multiple logistic regression model, mild and heavy proteinuria each associated with an increased odds of CSA-AKI, independent of CKD stage and the presence of diabetes mellitus (mild: OR 1.66, 95% CI 1.09 to 2.52; heavy: OR 2.30, 95% CI 1.35 to 3.90). Heavy proteinuria also associated with increased odds of postoperative RRT (OR 7.29, 95% CI 3.00 to 17.73). In summary, these data suggest that preoperative proteinuria is a predictor of CSA-AKI among patients undergoing CABG.
Introduction
Pangenotypic direct-acting antivirals are expected to cure hepatitis C virus (HCV) in more than 95% of treated patients. However, data on the effectiveness and safety of ...sofosbuvir/velpatasvir (SOF/VEL) in Taiwan are limited. This study aims to characterize the patient population in the nationwide Taiwan Association for the Study of the Liver (TASL) HCV Registry and evaluate treatment outcome in Taiwanese patients receiving SOF/VEL.
Methods
This study was a retrospective-prospective, observational, multicenter, real-world analysis. Adults with chronic hepatitis C were treated with SOF/VEL 400/100 mg ± ribavirin for 12 weeks. The primary outcome was sustained virologic response 12 weeks after end of therapy (SVR12). Factors associated with not achieving SVR12 were evaluated using logistic regression and covariate analysis. Safety was also assessed.
Results
In total, 3480 patients were included: 86.8% genotype 1/2, 2.8% genotype 3, 0.1% genotype 4/5, 9.6% genotype 6; unclassified, 0.8%; 12.2% compensated cirrhosis; 3.3% decompensated cirrhosis; and 15.8% chronic kidney disease. Overall SVR12 rate was 99.4% (genotype 1, 99.5%; genotype 2, 99.4%; genotype 3, 96.9%; genotype 4, 100%; genotype 6, 99.7%). SVR12 rates among patients with compensated cirrhosis, decompensated cirrhosis, and chronic kidney disease stages 4–5 were 99.5%, 100%, and 100%, respectively. There were 21 patients (0.6%) who did not achieve SVR12. Factors associated with failure were treatment adherence below 60%, high viral load, and genotype 3 (
p
< 0.001,
p
= 0.028, and
p
= 0.001, respectively). Adverse events occurred in 10% of patients; 0.6% were serious and one was related to treatment. Treatment discontinuation occurred in 0.3% of patients; none were treatment related. The estimated glomerular filtration rate remained stable throughout treatment and follow-up, regardless of baseline values and cirrhosis status.
Conclusion
SOF/VEL was highly effective and well tolerated in Taiwanese patients, irrespective of viral genotype, liver disease severity, and comorbidities.
Monocots are a major taxon within flowering plants, have unique morphological traits, and show an extraordinary diversity in lifestyle. To improve our understanding of monocot origin and evolution, ...we generate chromosome-level reference genomes of the diploid Acorus gramineus and the tetraploid Ac. calamus, the only two accepted species from the family Acoraceae, which form a sister lineage to all other monocots. Comparing the genomes of Ac. gramineus and Ac. calamus, we suggest that Ac. gramineus is not a potential diploid progenitor of Ac. calamus, and Ac. calamus is an allotetraploid with two subgenomes A, and B, presenting asymmetric evolution and B subgenome dominance. Both the diploid genome of Ac. gramineus and the subgenomes A and B of Ac. calamus show clear evidence of whole-genome duplication (WGD), but Acoraceae does not seem to share an older WGD that is shared by most other monocots. We reconstruct an ancestral monocot karyotype and gene toolkit, and discuss scenarios that explain the complex history of the Acorus genome. Our analyses show that the ancestors of monocots exhibit mosaic genomic features, likely important for that appeared in early monocot evolution, providing fundamental insights into the origin, evolution, and diversification of monocots.
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