Quantum states of quasiparticles in solids are dictated by symmetry. We experimentally demonstrate Dirac electrons in a two-dimensional quasicrystal without translational symmetry. A dodecagonal ...quasicrystalline order was realized by epitaxial growth of twisted bilayer graphene rotated exactly 30°. The graphene quasicrystal was grown up to a millimeter scale on an SiC (0001) surface while maintaining the single rotation angle over an entire sample and was successfully isolated from a substrate, demonstrating its structural and chemical stability under ambient conditions. Multiple Dirac cones replicated with the 12-fold rotational symmetry were observed in angle-resolved photoemission spectra, which revealed anomalous strong interlayer coupling with quasi-periodicity. Our study provides a way to explore physical properties of relativistic fermions with controllable quasicrystalline orders.
Chiral photonics has emerged as a key technology for future optoelectronics, such as quantum information and encryption, by making use of photonic waves from enantiomeric structures. An inevitable ...challenge for realizing such chiral optoelectronics is the development of near‐infrared circularly polarized (NIR CP) light‐sensing photodetectors that convert optical power and circular polarization direction into distinguishable electrical signals. Herein, a simple and promising strategy for high‐performance NIR CP light‐sensing organic phototransistors (NIR CPL‐OPTRs) applicable to highly secure optoelectronic encryption is proposed. By directly assembling a standalone cholesteric liquid‐crystal network film in a thin‐film NIR CPL‐OPTR, remarkable responsivity and distinguishability are achieved. The synergetic effect of amplification of the photocurrent signal by the applied electric field and improved light absorption by the reduced reflection in the multilayered structure leads to high responsivity. As a proof‐of‐concept, the chiral phototransistor arrays are demonstrated as a physically unclonable function device and exhibit enhanced cryptographic characteristics.
High‐performance near‐infrared circularly polarized light‐sensing organic phototransistors are realized by directly assembling a standalone cholesteric liquid‐crystal network film in the near‐infrared‐sensing organic phototransistor based on a small‐bandgap polymer semiconductor. A physical unclonable function device based on the chiral phototransistor arrays can enhance cryptographic characteristics by encoding the polarization direction of the circularly polarized light.
Cholesteric liquid crystal elastomers (CLCEs) are unique anisotropic rubbers that can change their structural color in response to various stimuli such as heat, chemicals, electric fields, and ...mechanical stress. Methods such as anisotropic deswelling and surface alignment have been adopted to prepare CLCEs; however, they have limitations in creating spatially controlled CLCE geometries. In this work, a direct ink writing (DIW)‐based 3D‐printable CLCE that can be prepared by extruding viscous CLC ink is developed through a 3D printer nozzle, followed by photopolymerization. Interestingly, the helical axis is inclined to the printing direction by ≈32° due to a combination of the shear‐induced alignment causes during extrusion and the elongational force generated during deposition onto the substrate. This unusual helical axis distortion leads to both blue and red shifts of the reflection color depending on the direction of observation relative to the printing axis. Notably, the printed CLCE exhibits anisotropic mechanochromism upon stretching, because of the stretching‐direction‐dependent variations in the slant angle of the helical axis. This anisotropic mechanochromism can be harnessed to develop a unique CLCE‐based strain sensor displaying intricate color patterns upon stretching, with significant application potential in encryption, anticounterfeiting, and structural health monitoring.
Cholesteric liquid crystal elastomers (CLCEs) with slanted helices are prepared by direct ink writing‐based 3D printing. The anisotropic mechanochromic response of the printed CLCE to being stretched relative to the printing direction has been observed for the first time, thereby enabling the creation of a unique strain sensor displaying intricate color patterns.
Abstract Background We aimed to investigate the outcome-predicting value of a novel index of stress hyperglycemia in coronary artery disease (CAD) patients who underwent percutaneous coronary ...intervention (PCI). Methods This was a retrospective observational study. Four-thousand-three-hundred-sixty-two subjects from the COACT registry were used to estimate the risk of major adverse cardiovascular and cerebrovascular events (MACCE), which are defined as composites of all-cause death, non-fatal myocardial infarction (MI) and non-fatal stroke. The stress hyperglycemia ratio (SHR) was calculated by dividing the random serum glucose at admission with the estimated average glucose derived from HbA1c. Results Over a median follow-up of 2.5 years, 344 (7.9%), 43 (1.0%), and 89 (2.0%) cases of death, non-fatal MI, and non-fatal stroke occurred, respectively. Compared with the subjects in the lower three quartiles of SHR, the HR (95% CI) for the highest SHR quartile (Q4) group for MACCE was 1.31 (1.05, 1.64) in the total population and 1.45 (1.02, 2.06) in the non-diabetic population after adjusting for potential covariables. The risk of MACCE in the SHR Q4 group was significantly higher in patients presenting with ST-elevation MI (STEMI), which was not the case for patients presenting with other CAD types. The prognostic impact of SHR was more prominent for the 30-day MACCE. Similar results were observed in another cohort consisting of patients who only presented with acute MI. Conclusions SHR is a useful predictive marker of MACCE after PCI, especially in non-diabetic patients with STEMI, which could be utilized to identify high-risk patients for adverse outcomes.
Cardiac resynchronization therapy (CRT) strategy for heart failure with mildly reduced ejection fraction (HFmrEF) is controversial. Left bundle branch area pacing (LBBAP) is an emerging pacing ...modality and an alternative option to CRT. This analysis aimed to perform a systematic review of the literature and meta‐analysis on the impact of the LBBAP strategy in HFmrEF, with left ventricular ejection fraction (LVEF) between 35% and 50%. PubMed, Embase, and Cochrane Library were searched for full‐text articles on LBBAP from inception to July 17, 2022. The outcomes of interest were QRS duration and LVEF at baseline and follow‐up in mid‐range heart failure. Data were extracted and summarized. A random‐effect model incorporating the potential heterogeneity was used to synthesize the results. Out of 1065 articles, 8 met the inclusion criteria for 211 mid‐range heart failure patients with an implant LBBAP across the 16 centers. The average implant success rate with lumenless pacing lead use was 91.3%, and 19 complications were reported among all 211 enrolled patients. During the average follow‐up of 9.1 months, the average LVEF was 39.8% at baseline and 50.5% at follow‐up (MD: 10.90%, 95% CI: 6.56−15.23, p < .01). Average QRS duration was 152.6 ms at baseline and 119.3 ms at follow‐up (MD: −34.51 ms, 95% CI: −60.00 to −9.02, p < .01). LBBAP could significantly reduce QRS duration and improve systolic function in a patient with LVEF between 35% and 50%. Application of LBBAP as a CRT strategy for HFmrEF may be a viable option.
Average left ventricular ejection fraction (LVEF) from implant to follow‐up for baseline LVEF between 35% and 50% versus LVEF <35%.
▪ Left bundle branch area pacing (LBBAP) was found to significantly shorten QRS duration and improve systolic cardiac function in patients with a LVEF of 35%−50%.
▪ In patients with heart failure with mildly reduced ejection fraction, LBBAP resulted in a significant increase in ejection fraction.
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•High-temperature high cycle fatigue (HCF) behavior of HIPed LPBF 625 was investigated.•HIPed LPBF and wrought alloys show similar grain size and grain boundary characteristics.•Al2O3 ...particles were detected in HIPed LPBF 625, and carbides were observed in wrought 625.•HIPed LPBF 625 has a lower HCF limit (500 MPa) compared to wrought 625 (550 MPa).•Higher sulfur content (HIPed LPBF 625) might be a reason for lower HCF properties at 650 ℃.
High-temperature tensile and high cycle fatigue properties of hot isostatic pressed LPBF Inconel 625 (laser powder bed fusion, HIPed LPBF 625) were investigated and then compared to conventional wrought Inconel 625. HIPed LPBF and wrought alloys show similar microstructural characteristics in average grain size, defects, fraction of special grain boundaries, and grain morphologies. However, Al2O3 and TiN phase was found (without carbides) in HIPed LPBF 625, and various stoichiometry of carbides (without Al2O3) were identified in wrought 625. The yield and tensile strengths and elongation at fracture of both alloys have similar values at room temperature. At 650 °C, elongation at fracture of HIPed LPBF 625 significantly decreases compared to that of wrought 625. HIPed LPBF 625 also has a lower high-cycle fatigue limit of 500 MPa (at 107 cycles without fracture) and shorter life in low-stress conditions compared to wrought 625. The relatively higher sulfur content in HIPed LPBF 625 (33 ppm) is suggested as the reason for lower fatigue endurance at 650 °C. The LPBF (or additive manufacturing), which uses powder feedstock, is vulnerable to impurity concentration increases, elemental contamination control is critical in the initial powder and LPBF process.
Objective
To assess the diagnostic performance of dual-energy computed tomography (DECT) with the color-coded virtual non-calcium (VNC) technique for detecting acute fractures in patients after acute ...spine trauma, especially in an emergency clinical setting.
Materials and methods
Our retrospective study included 31 patients presented to emergency department with suspected spine trauma. All patients underwent both DECT (80 kVp and 140 kVp) and MRI. Post-processing was performed using color-coded VNC technique. Two independent radiologists visually assessed color-coded VNC images in a random order, and one of the two readers re-assessed the images in 4 weeks after the initial assessment. They were allowed to read only color-coded VNC images and asked to determine the presence of acute fracture. To determine the standard reference point, the other two experienced radiologists made consensus readings on both grayscale CT and MRI. Sensitivity, specificity, PPV, NPV, and accuracy analyses were determined. Both intra- and inter-observer agreements were also calculated.
Results
A total of 217 vertebral bodies (65 thoracic and 152 lumbar vertebrae) were included in our study. Sensitivity was 83.3% and 76.7% for first and second readers, respectively. Specificity of 99.5% and 98.9%, PPV of 96.1% and 96.3%, NPV of 97.3% and 96.3%, and accuracy of 97.2% and 95.8%, respectively, were noted. Both intra-observer and inter-observer agreements indicated excellent agreement (
κ
= 0.86 and
κ
= 0.84, respectively).
Conclusion
In spite of the relatively low sensitivity, DECT-based detection of acute spinal fractures showed good specificity, positive predictive value, negative predictive value, accuracy, and inter-/intra-observer agreements.
Both anticoagulation and antiplatelet therapies are recommended after percutaneous coronary intervention (PCI) in patients with atrial fibrillation (AF). Although contemporary guidelines recommend ...discontinuation of antiplatelet therapy 1 year after drug-eluting stent (DES) implantation due to excessive bleeding risk, supporting randomized trials are still lacking.
The ADAPT AF-DES trial is a multicenter, prospective, open-label, randomized, non-inferiority trial, enrolling 960 patients with AF with a CHA2DS2-VASc score > 1, who underwent PCI with DES implantation at least 12 months before enrollment. Eligible patients are randomly assigned to receive either non-vitamin K antagonist oral anticoagulant (NOAC) monotherapy or NOAC plus clopidogrel combination therapy. The primary outcome is net adverse clinical event (NACE) at 1 year after randomization, defined as a composite of all-cause death, myocardial infarction, stent thrombosis, stroke, systemic embolism, and major or clinically relevant non-major bleeding, as defined by the International Society on Thrombosis and Hemostasis criteria. We hypothesize that NOAC monotherapy would be non-inferior to NOAC plus clopidogrel combination therapy for NACE in patients with AF beyond 12 months after DES implantation.
The ADAPT AF-DES trial will evaluate the efficacy and safety of NOAC monotherapy versus NOAC plus clopidogrel combination therapy in patients with AF beyond 12 months after PCI with DES implantation. The ADAPT AF-DES trial will provide robust evidence for an optimal antithrombotic strategy in patients with AF after DES implantation.
https://www.clinicaltrials.gov. Unique identifier: NCT04250116.
Vertical and lateral heterogeneous structures of two-dimensional (2D) materials have paved the way for pioneering studies on the physics and applications of 2D materials. A hybridized hexagonal boron ...nitride (h-BN) and graphene lateral structure, a heterogeneous 2D structure, has been fabricated on single-crystal metals or metal foils by chemical vapor deposition (CVD). However, once fabricated on metals, the h-BN/graphene lateral structures require an additional transfer process for device applications, as reported for CVD graphene grown on metal foils. Here, we demonstrate that a single-crystal h-BN/graphene lateral structure can be epitaxially grown on a wide-gap semiconductor, SiC(0001). First, a single-crystal h-BN layer with the same orientation as bulk SiC was grown on a Si-terminated SiC substrate at 850 °C using borazine molecules. Second, when heated above 1150 °C in vacuum, the h-BN layer was partially removed and, subsequently, replaced with graphene domains. Interestingly, these graphene domains possess the same orientation as the h-BN layer, resulting in a single-crystal h-BN/graphene lateral structure on a whole sample area. For temperatures above 1600 °C, the single-crystal h-BN layer was completely replaced by the single-crystal graphene layer. The crystalline structure, electronic band structure, and atomic structure of the h-BN/graphene lateral structure were studied by using low energy electron diffraction, angle-resolved photoemission spectroscopy, and scanning tunneling microscopy, respectively. The h-BN/graphene lateral structure fabricated on a wide-gap semiconductor substrate can be directly applied to devices without a further transfer process, as reported for epitaxial graphene on a SiC substrate.
Direct addition of sulfur-reducing agents during anaerobic digestion (AD) is very effective in controlling hydrogen sulfide (H2S) content in biogas, although one major problem is the high operational ...cost due to the large amount of chemicals used. The objective of this study was to remove H2S using a waste mill scale (MS) as a sulfur-reducing agent. To evaluate its feasibility, MS was added to AD fed with food waste (FW) at concentrations between 0 and 160 g MS/kg total chemical oxygen demand (TCOD) during the batch test, and the experimental results were compared to those of the batch test with the addition of iron chloride (FeCl3). Both FeCl3 and MS played an important role as electro-conductive materials in improving methane productivity by promoting direct interspecies electron transfer. An increase in H2S removal efficiency was observed with increases in both materials. In total, 30%, 60%, and 90% of H2S production based on the maximum sulfur in the form of H2S (control) was 3.7, 9.4, and 23.8 g FeCl3/kg TCOD and 13.3, 34.1, and 86.2 g MS/kg TCOD, respectively. This finding indicates that MS can be used as a sulfur-reducing agent substitute for H2S removal in AD fed with FW.
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