Manipulating a quantum state via electrostatic gating has been of great importance for many model systems in nanoelectronics. Until now, however, controlling the electron spins or, more specifically, ...the magnetism of a system by electric-field tuning has proven challenging
. Recently, atomically thin magnetic semiconductors have attracted significant attention due to their emerging new physical phenomena
. However, many issues are yet to be resolved to convincingly demonstrate gate-controllable magnetism in these two-dimensional materials. Here, we show that, via electrostatic gating, a strong field effect can be observed in devices based on few-layered ferromagnetic semiconducting Cr
Ge
Te
. At different gate doping, micro-area Kerr measurements in the studied devices demonstrate bipolar tunable magnetization loops below the Curie temperature, which is tentatively attributed to the moment rebalance in the spin-polarized band structure. Our findings of electric-field-controlled magnetism in van der Waals magnets show possibilities for potential applications in new-generation magnetic memory storage, sensors and spintronics.
Graphene-base transistors have been proposed for high-frequency applications because of the negligible base transit time induced by the atomic thickness of graphene. However, generally used tunnel ...emitters suffer from high emitter potential-barrier-height which limits the transistor performance towards terahertz operation. To overcome this issue, a graphene-base heterojunction transistor has been proposed theoretically where the graphene base is sandwiched by silicon layers. Here we demonstrate a vertical silicon-graphene-germanium transistor where a Schottky emitter constructed by single-crystal silicon and single-layer graphene is achieved. Such Schottky emitter shows a current of 692 A cm
and a capacitance of 41 nF cm
, and thus the alpha cut-off frequency of the transistor is expected to increase from about 1 MHz by using the previous tunnel emitters to above 1 GHz by using the current Schottky emitter. With further engineering, the semiconductor-graphene-semiconductor transistor is expected to be one of the most promising devices for ultra-high frequency operation.
•Indoor view-based visibility analysis method using point cloud is proposed.•Line-of-sight correction can address the influence of point cloud void on visibility.•Viewshed images reflect the real ...environment's impact on visibility.•Many other visual factors can be assessed by utilizing viewshed image.
Visibility analysis is a crucial geographic information processing method, used to assess the observable spatial range from a particular location under specific conditions. It has broad applications, such as urban planning, landscape design and environmental research. Laser scanning provides detailed and accurate 3D data for visibility analysis, called point cloud. However, certain deficiencies still exist in current point cloud-based visibility analysis methods. Few methods are developed from indoor perspective and the influence of point cloud void is rarely considered. Firstly, indoor viewpoints are generated based on the windows extracted from terrestrial laser scanning (TLS) point cloud and unmanned aerial vehicle (UAV) point cloud is used to provide 3D representation of the environment around the viewpoint. Then, a half-sphere viewshed is created for each indoor viewpoint to analyze the visible spatial range. In this step, a novel line-of-sight correction method is proposed based on the semantic information from UAV point cloud, to correct the biased observation distance resulted from point cloud voids. Lastly, the volume of visible space is calculated based on the corrected viewshed image, to evaluate the visibility of each indoor viewpoint. Our method is validated on two datasets. The results indicate that our method enables more accurate simulation of visible space compared with previous studies by considering the effect of point cloud void. The proposed method can support the urban design from the perspective of indoor visual perception and accurate calculation of other visual factors in visual quality evaluation.
Growth of large-area, uniform, and high-quality monolayer transition-metal dichalcogenides (TMDs) for practical and industrial applications remains a long-standing challenge. The present study ...demonstrates a modified predeposited chemical vapor deposition (CVD) process by employing an annealing procedure before sulfurization, which helps in achieving large-area, highly uniform, and high-quality TMDs on various substrates. The annealing procedure resulted in a molten liquid state of the precursors in the CVD process, which not only facilitated a uniform redistribution of the precursor on the substrate (avoid the aggregation) because of the uniform redistribution of the liquid precursor on the substrate but more importantly avoided the undesired multilayer growth via the self-limited lateral supply precursors mechanism. A 2 in. uniform and continuous monolayer WS2 film has been synthesized on the SiO2/Si substrate. Moreover, uniform monolayer WS2 single crystals can be prepared on more general and various substrates including sapphire, mica, quartz, and Si3N4 using the same growth procedure. Besides, this growth mechanism can be generalized to synthesize other monolayer TMDs such as MoS2 and MoS2/WS2 heterostructures. Hence, the present method provides a generalized attractive strategy to grow large-area, uniform, single-layer two-dimensional (2D) materials. This study has significant implications in the advancement of batch production of various 2D-material-based devices for industrial and commercial applications.
The triglyceride-glucose (TyG) index is an alternative marker of insulin resistance (IR) and is closely associated with the prevalence and prognosis of atherosclerotic cardiovascular disease (ASCVD). ...However, the association between the TyG index and in-stent restenosis (ISR) after drug-eluting stent (DES) implantation in patients with acute coronary syndrome (ACS) remains unknown.
The present study retrospectively recruited patients who were admitted for ACS and underwent coronary angiography at 6 to 24 months after successful DES-based percutaneous coronary intervention (PCI). In addition, we calculated the TyG index with the following formula: Ln(fasting triglyceride mg/dL × fasting blood glucose mg/dL/2) and divided patients into 3 groups according to the tertile of the TyG index. Most importantly, multivariate logistic regression analysis models were also constructed to assess the association between the TyG index and DES-ISR in patients with ACS.
A total of 1574 patients with ACS (58.4 ± 9.4 years, 77.4% male) were included in this study. At the median follow-up time of 12 (9-14) months, the prevalence of DES-ISR increased stepwise with the increasing tertile of the TyG index (11.6% vs 17.3% vs 19.4%, p = 0.002), and the TyG index was also higher in the ISR group than in the non-ISR group (9.00 ± 0.58 vs 8.84 ± 0.61, p < 0.001). In addition, the positive association between the TyG index and the prevalence of DES-ISR was also determined in the fully adjusted model (TyG, per 1-unit increase: OR 1.424, 95% CI 1.116 to 1.818, p = 0.005; tertile of TyG, the OR (95% CI) values for tertile 2 and tertile 3 were 1.454 (1.013 to 2.087) and 1.634 (1.125 to 2.374), respectively, with tertile 1 as a reference). The association was also reflected in most subgroups. Moreover, adding the TyG index to the predictive model for DES-ISR in patients with ACS could contribute to an increase in C-statistics (0.675 vs 0.659, p = 0.010), categorical net reclassification improvement (0.090, p < 0.001), and integrated discrimination improvement (0.004, p = 0.040).
An elevated TyG index was independently and positively associated with DES-ISR in patients with ACS who underwent PCI. However, the incremental predictive value of the TyG index for DES-ISR was slight. To further confirm our findings, future studies are needed.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Abstract
Two-dimensional (2D) materials are promising for next-generation photo detection because of their exceptional properties such as a strong interaction with light, electronic and optical ...properties that depend on the number of layers, and the ability to form hybrid structures. However, the intrinsic detection ability of 2D material-based photodetectors is low due to their atomic thickness. Photogating is widely used to improve the responsivity of devices, which usually generates large noise current, resulting in limited detectivity. Here, we report a molybdenum-based phototransistor with MoS
2
channel and α-MoO
3-x
contact electrodes. The device works in a photo-induced barrier-lowering (PIBL) mechanism and its double heterojunctions between the channel and the electrodes can provide positive feedback to each other. As a result, a detectivity of 9.8 × 10
16
cm Hz
1/2
W
−1
has been achieved. The proposed double heterojunction PIBL mechanism adds to the techniques available for the fabrication of 2D material-based phototransistors with an ultrahigh photosensitivity.
An innovative method for synthesizing optimum difference patterns of the spherical sensor array is introduced, along with a sidelobe tapering technique. Firstly, we suggest employing the spherical ...harmonics of degree ±1 to synthesize the spherical array difference pattern; secondly, we study the mapping relationship between the difference pattern of the spherical sensor array and the difference pattern of the uniformly spaced linear array (ULA) with odd-numbered elements; finally, we enhance the Zolotarev difference pattern, which is a counterpart to the Dolph-Chebyshev sum pattern that traditionally allows synthesis only for ULA with even-numbered elements. Our modification extends its applicability to synthesize difference patterns for ULA with odd-numbered elements. Leveraging the optimal difference pattern, a generalized Bayliss difference pattern synthesis method designed for the ULA with odd-numbered elements is further proposed. To illustrate the effectiveness of our approach, we present several design examples through experimental simulation.
Spoofing interference is one of the most emerging threats to the Global Navigation Satellite System (GNSS); therefore, the research on anti-spoofing technology is of great significance to improving ...the security of GNSS. For single spoofing source interference, all the spoofing signals are broadcast from the same antenna. When the receiver is in motion, the pseudo-range of spoofing signals changes nonlinearly, while the difference between any two pseudo-ranges changes linearly. Authentic signals do not have this characteristic. On this basis, an anti-spoofing method is proposed by jointly monitoring the linearity of the pseudo-range difference (PRD) sequence and pseudo-range sum (PRS) sequence, which transforms the spoofing detection problem into the sequence linearity detection problem. In this paper, the model of PRD and PRS is derived, the hypothesis based on the linearity of PRD sequence and PRS sequence is given, and the detection performance of the method is evaluated. This method uses the sum of squares of errors (SSE) of linear fitting of the PRD sequence and PRS sequence to construct detection statistics, and has low computational complexity. Simulation results show that this method can effectively detect spoofing interference and distinguish spoofing signals from authentic signals.
Aim: Recently, the atherogenic index of plasma (AIP) has been proposed as a novel, reliable plasma atherogenicity marker. This study aimed to investigate the association of AIP with the risk of ...in-stent restenosis (ISR) in patients with acute coronary syndrome (ACS). Methods: This study retrospectively enrolled patients with ACS followed by angiography within 6 to 18 months after successful percutaneous coronary intervention (PCI) with a drug-eluting stent (DES). And the participants were divided into ISR or non-ISR groups based on the angiographic follow-up results. AIP was defined as the base 10 logarithm of the ratio of serum triglyceride (mmol/L) to high-density lipoprotein cholesterol (mmol/L).Results: This study recruited 1319 patients with ACS, 199 of which had ISR. Compared with the non-ISR group, patients in the ISR group had higher level of AIP (0.199±0.290 vs 0.131±0.282, p=0.002). In the multiple logistic regression analysis, AIP was an independent risk factor for DES-ISR (OR=2.100, 95% CI 1.134 to 3.891, p=0.018). When we modulated AIP as a categorical variable, the risk of DES-ISR increased in quartile 4 compared to quartile 1 (OR=1.713, 95% CI 1.040 to 2.822, p=0.034). Furthermore, this association remains stable in various subgroups. Unexpectedly, the subgroup analysis suggested AIP and DES-ISR had a stronger positive association in individuals with low-density lipoprotein cholesterol (LDL-C) ＜1.8 mmol/L.Conclusions: AIP and the risk of DES-ISR were positively and independently correlated in patients with ACS, especially in those with an LDL-C ＜1.8 mmol/L.
The aim of our study was to analyze the risk factors of nosocomial infection after cardiac surgery in children with congenital heart disease (CHD).
We performed a retrospective cohort study, and ...children with CHD who underwent open-heart surgeries at Shanghai Children's Medical Center from January 1, 2012 to December 31, 2018 were included. The baseline characteristics of these patients of different ages, including neonates (0-1 months old), infants (1-12 months old) and children (1-10 years old), were analyzed, and the association of risk factors with postoperative nosocomial infection were assessed.
A total of 11,651 subjects were included in the study. The overall nosocomial infection rate was 10.8%. Nosocomial infection rates in neonates, infants, and children with congenital heart disease were 32.9, 15.4, and 5.2%, respectively. Multivariate logistic regression analysis found age (OR 0798, 95%CI: 0.769-0.829; P < 0.001), STS risk grade (OR 1.267, 95%CI: 1.159-1.385; P < 0.001), body mass index (BMI) <5th percentile (OR 1.295, 95%CI: 1.023-1.639; P = 0.032), BMI >95th percentile (OR 0.792, 95%CI: 0.647-0.969; P = 0.023), cardiopulmonary bypass (CPB) time (OR 1.008, 95%CI: 1.003-1.012; P < 0.001) and aortic clamping time (OR 1.009, 1.002-1.015; P = 0.008) were significantly associated with nosocomial infection in CHD infants. After adjusted for confounding factors, we found STS risk grade (OR 1.38, 95%CI: 1.167-1.633; P < 0.001), BMI < 5th percentile (OR 1.934, 95%CI: 1.377-2.715; P < 0.001), CPB time (OR 1.018, 95%CI: 1.015-1.022; P < 0.001), lymphocyte/WBC ratio<cut off value (OR 3.818, 95%CI: 1.529-9.533; P = 0.004) and AST>cut off value (OR 1.546, 95%CI: 1.119-2.136; P = 0.008) were significantly associated with nosocomial infection in CHD children.
Our study suggested STS risk grade, BMI, CPB duration, low lymphocyte/WBC or high neutrophil/WBC ratio were independently associated with nosocomial infection in CHD infant and children after cardiac surgery.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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