Higher-order topological insulators are newly proposed topological phases of matter, whose bulk topology manifests as localized modes at two- or higher-dimensional lower boundaries. In this Letter, ...we propose the twisted bilayer graphenes with large angles as higher-order topological insulators, hosting topological corner charges. At large commensurate angles, the intervalley scattering opens up the bulk gap and the corner states occur at half filling. Based on both first-principles calculations and analytic analysis, we show the striking results that the emergence of the corner states do not depend on the choice of the specific angles as long as the underlying symmetries are intact. Our results show that the twisted bilayer graphene can serve as a robust candidate material of a two-dimensional higher-order topological insulator.
M-theoretic genesis of topological phases Cho, Gil Young; Gang, Dongmin; Kim, Hee-Cheol
The journal of high energy physics,
11/2020, Letnik:
2020, Številka:
11
Journal Article
Recenzirano
Odprti dostop
A
bstract
We present a novel M-theoretic approach of constructing and classifying anyonic topological phases of matter, by establishing a correspondence between (2+1)d topological field theories and ...non-hyperbolic 3-manifolds. In this construction, the topological phases emerge as macroscopic world-volume theories of M5-branes wrapped around certain types of non-hyperbolic 3-manifolds. We devise a systematic algorithm for identifying the emergent topological phases from topological data of the internal wrapped 3-manifolds. As a benchmark of our approach, we reproduce all the known unitary bosonic topological orders up to rank 4. Remarkably, our construction is not restricted to an unitary bosonic theory but it can also generate fermionic and/or non-unitary anyon models in an equivalent fashion. Hence, we pave a new route toward the classification of topological phases of matter.
Background
The comprehensive complication index (CCI) integrates all complications of the Clavien–Dindo classification (CDC) and offers a metric approach to measure morbidity. The aim of this study ...was to evaluate the CCI at a high-volume center for gastric cancer surgery and to compare the CCI to the conventional CDC.
Methods
Clinical factors were collected from the prospective complication data of gastric cancer patients who underwent radical gastrectomy at Seoul National University Hospital from 2013 to 2014. CDC and CCI were calculated, and risk factors were investigated. Correlations and generalized linear models of hospital stay were compared between the CCI and CDC. The complication monitoring model with cumulative sum control-CCI (CUSUM-CCI) was displayed for individual surgeons, for comparisons between surgeons, and for the institution.
Results
From 1660 patients, 583 complications in 424 patients (25.5%) were identified. The rate of CDC grade IIIa or greater was 9.7%, and the overall CCI was 5.8 ± 11.7. Age, gender, Charlson score, combined resection, open method, and total gastrectomy were associated with increased CCI (
p
< 0.05). The CCI demonstrated a stronger relationship with hospital stay (
ρ
= 0.721,
p
< 0.001) than did the CDC (
ρ
= 0.634,
p
< 0.001). For prolonged hospital stays (≥30 days), only the CCI showed a moderate correlation (
ρ
= 0.544,
p
= 0.024), although the CDC did not. The CUSUM-CCI model displayed dynamic time–event differences in individual and comparison monitoring models. In the institution monitoring model, a gradual decrease in the CCI was observed.
Conclusions
The CCI is more strongly correlated with postoperative hospital stay than is the conventional CDC. The CUSUM-CCI model can be used for the continuous monitoring of surgical quality.
Suicide is not only an individual phenomenon, but it is also influenced by social and environmental factors. With the high suicide rate and the abundance of social media data in South Korea, we have ...studied the potential of this new medium for predicting completed suicide at the population level. We tested two social media variables (suicide-related and dysphoria-related weblog entries) along with classical social, economic and meteorological variables as predictors of suicide over 3 years (2008 through 2010). Both social media variables were powerfully associated with suicide frequency. The suicide variable displayed high variability and was reactive to celebrity suicide events, while the dysphoria variable showed longer secular trends, with lower variability. We interpret these as reflections of social affect and social mood, respectively. In the final multivariate model, the two social media variables, especially the dysphoria variable, displaced two classical economic predictors - consumer price index and unemployment rate. The prediction model developed with the 2-year training data set (2008 through 2009) was validated in the data for 2010 and was robust in a sensitivity analysis controlling for celebrity suicide effects. These results indicate that social media data may be of value in national suicide forecasting and prevention.
This article introduces a 16-Gb T-coil-based graphics double-data-rate 6 (GDDR6) dynamic random access memory (DRAM) with merged-multiplexer (MUX) transmitter (TX), optimized data clock (WCK) ...operation to enhance I/O bandwidth. T-coil is implemented for the first time in a DRAM process. Moreover, an alternative-data-bus (ADB) is employed to solve the frequency limit of the data bus. The proposed T-coil-based GDDR6 DRAM achieves 27 Gb/s/pin with 1.35 V in a DRAM process.
Mesenchymal stem cells (MSCs) are known to have a potential for articular cartilage regeneration. However, most studies focused on focal cartilage defect through surgical implantation. For the ...treatment of generalized cartilage loss in osteoarthritis, an alternative delivery strategy would be more appropriate. The purpose of this study was to assess the safety and efficacy of intra-articular injection of autologous adipose tissue derived MSCs (AD-MSCs) for knee osteoarthritis. We enrolled 18 patients with osteoarthritis of the knee and injected AD MSCs into the knee. The phase I study consists of three dose-escalation cohorts; the low-dose (1.0 × 10(7) cells), mid-dose (5.0 × 10(7)), and high-dose (1.0 × 10(8)) group with three patients each. The phase II included nine patients receiving the high-dose. The primary outcomes were the safety and the Western Ontario and McMaster Universities Osteoarthritis index (WOMAC) at 6 months. Secondary outcomes included clinical, radiological, arthroscopic, and histological evaluations. There was no treatment-related adverse event. The WOMAC score improved at 6 months after injection in the high-dose group. The size of cartilage defect decreased while the volume of cartilage increased in the medial femoral and tibial condyles of the high-dose group. Arthroscopy showed that the size of cartilage defect decreased in the medial femoral and medial tibial condyles of the high-dose group. Histology demonstrated thick, hyaline-like cartilage regeneration. These results showed that intra-articular injection of 1.0 × 10(8) AD MSCs into the osteoarthritic knee improved function and pain of the knee joint without causing adverse events, and reduced cartilage defects by regeneration of hyaline-like articular cartilage.
▶ Treadmill exercise ameliorates cognitive deficits in Tg mice. ▶ Treadmill exercise reduces Aβ-42 and tau deposition in Tg mice. ▶ Treadmill exercise reduces the number of TUNEL-positive cells in Tg ...mice. ▶ Treadmill exercise reduces TC, insulin, glucose, and corticosterone levels in Tg mice. ▶ Treadmill exercise may be beneficial in prevention or treatment in AD.
The present study was undertaken to further investigate the protective effect of treadmill exercise on the hippocampal proteins associated with neuronal cell death in an aged transgenic (Tg) mice with Alzheimer's disease (AD). To address this, Tg mouse model of AD, Tg-NSE/PS2m, which expresses human mutant PS2 in the brain, was chosen. Animals were subjected to treadmill exercise for 12 weeks from 24 months of age. The exercised mice were treadmill run at speed of 12
m/min, 60
min/day, 5 days/week on a 0% gradient for 3 months. Treadmill exercised mice improved cognitive function in water maze test. Treadmill exercised mice significantly reduced the expression of Aβ-42, Cox-2, and caspase-3 in the hippocampus. In parallel, treadmill exercised Tg mice decreased the phosphorylation levels of JNK, p38MAPK and tau (Ser404, Ser202, Thr231), and increased the phosphorylation levels of ERK, PI3K, Akt and GSK-3α/β. In addition, treadmill exercised Tg mice up-regulated the expressions of NGF, BDNF and phospho-CREB, and the expressions of SOD-1, SOD-2 and HSP-70. Treadmill exercised Tg mice up-regulated the expression of Bcl-2, and down-regulated the expressions of cytochrome c and Bax in the hippocampus. The number of TUNEL-positive cells in the hippocampus in mice was significantly decreased after treadmill exercise. Finally, serum TC, insulin, glucose, and corticosterone levels were significantly decreased in the Tg mice after treadmill exercise. As a consequence of such change, Aβ-dependent neuronal cell death in the hippocampus of Tg mice was markedly suppressed following treadmill exercise. These results strongly suggest that treadmill exercise provides a therapeutic potential to inhibit both Aβ-42 and neuronal death pathways. Therefore, treadmill exercise may be beneficial in prevention or treatment of AD.
Potholes, a kind of road defect, can damage vehicles and negatively affect drivers’ safe driving, and in severe cases can lead to traffic accidents. Efficient and preventive management of potholes in ...a complex road environment plays an important role in securing driver safety. It is also expected to contribute to the prevention of traffic accidents and the smooth flow of traffic. In the past, pothole detection was mainly performed via visual inspection by human experts. Recently, automated pothole-detection methods apply various technologies that converge basic technologies such as sensors and signal processing. The automated pothole-detection methods can be classified into three types according to the technology used in the pothole-recognition process: a vision-based method, a vibration-based method, and a 3D reconstruction-based method. In this paper, three methods are compared, and the strengths and weaknesses of each method are summarized. The detection process and technology proposed in the latest research related to automated pothole detection are described for each method. The development plans of future technology that is connected with those studies are also presented in this paper.
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