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Objective The study objective was to determine whether mini-invasive transthoracoscopic atrial fibrillation ablation can delay the progression of atrial fibrillation from paroxysmal to persistent. Methods Patients aged 18 to 80 years with paroxysmal nonvalvular atrial fibrillation and a history of stroke or systemic thromboembolism were consecutively enrolled from September 2014 to June 2019. In the treatment group, patients underwent transthoracoscopic atrial fibrillation ablation plus left atrial appendage excision (atrial fibrillation ablation plus left atrial appendage excision group). Patients unwilling to receive surgical intervention were treated with antiarrhythmic drugs and oral anticoagulants and recruited as a control group (atrial fibrillation plus antiarrhythmic drugs group). The primary end point was the progression of atrial fibrillation from paroxysmal to persistent. Results This study included 49 patients in the atrial fibrillation plus antiarrhythmic drugs group (29 men) and 77 patients in the atrial fibrillation ablation plus left atrial appendage excision group (48 men). In the atrial fibrillation ablation plus left atrial appendage excision group, after a median follow-up of 951 days (interquartile range, 529-1366 days), 8 patients (10.4%) progressed to persistent atrial fibrillation. In the atrial fibrillation plus antiarrhythmic drugs group, after a median follow-up of 835 days (interquartile range, 548-1214 days), 14 patients (28.6%) progressed to persistent atrial fibrillation. The atrial fibrillation ablation plus left atrial appendage excision group had a significantly lower incidence of atrial fibrillation progression than the atrial fibrillation plus antiarrhythmic drugs group during follow-up (3.9 vs 12.3 per 100 person-years, log-rank 8.6, P = .003). Conclusions Patients with paroxysmal nonvalvular atrial fibrillation who chose to undergo transthoracoscopic atrial fibrillation ablation had a lower incidence of progression to persistent atrial fibrillation than patients who chose conservative therapy. This strategy might be especially suitable for patients with paroxysmal nonvalvular atrial fibrillation at high risk of stroke and high risk of bleeding.

In this paper we propose new Z-type nonlinear weights of the fifth-order weighted essentially non-oscillatory (WENO) finite difference scheme for hyperbolic conservation laws. Instead of employing the classical smoothness indicators for the nonlinear weights, we take the $p$th root of the smoothness indicators and follow the form of Z-type nonlinear weights, leading to fifth order accuracy in smooth regions, even at the critical points, and sharper approximations around the discontinuities. We also prove that the proposed nonlinear weights converge to the linear weights as $p \to \infty$, implying the convergence of the resulting WENO numerical flux to the finite difference numerical flux. Finally, numerical examples are presented by comparing with other WENO schemes, such as WENO-JS, WENO-M and WENO-Z, to demonstrate that the proposed WENO scheme performs better in shock capturing.

One key risk factor of aortic valve stenosis in clinical practice is bicuspid aortic valve (BAV). Increasing evidence indicates that numerous microRNAs (miRs/miRNAs) are involved in BAV calcification via their target genes. miR‑330‑3p was found to be involved in the deterioration of BAV calcification by miR profiling in human calcified BAV and tricuspid aortic valve (TAV) tissues in the present study and the underlying mechanism was investigated. RNA sequencing was performed on four BAV and four TAV tissues from patients with aortic stenosis before these leaflets were examined for the expression levels of miR‑330‑3p and CREB‑binding protein (CREBBP) by reverse transcription‑PCR. The alteration of functional factors associated with calcification was also assessed by Western blotting and immunohistochemistry in human aortic tissue samples. The putative target of miR‑330‑3p was detected by dual‑luciferase assay in 293 cells. Furthermore, the influence of miR‑330‑3p expression on osteogenic progression was explored in cultured porcine valve interstitial cells (VICs). Rescue experiments of CRBBP were performed to confirm the influence of the miR‑330‑3p‑CREBBP pathway in the calcification progress in porcine VICs. RNA sequencing indicated distinct expression of miR‑330‑3p in human BAV tissues compared with TAV, which was then confirmed by PCR. CREBBP expression levels in human BAV and TAV leaflets also demonstrated the opposite alterations. This negative correlation was then confirmed in cultured porcine VICs. Under an osteogenic environment, cellular calcification was promoted in miR‑330‑3p‑overexpressed porcine VICs expressing higher bone morphogenetic protein 2, Runt‑related transcription factor 2, matrix metalloproteinase (MMP)‑2, MMP‑9 and collagen I compared with controls. Rescue experiments further confirmed that miR‑330‑3p played its role via targeting CREBBP in porcine VICs. Collectively, miR‑330‑3p was upregulated in calcified BAV compared with TAV. The upregulation of miR‑330‑3p promotes the calcification progress partially via targeting CREBBP.

Background: A patent false lumen (FL) in patients with thoracic endovascular aortic repair (TEVAR)-treated type B aortic dissection (TBAD) can cause a significant risk for late aortic expansion (LAE). We hypothesize that preoperative features can predict the occurrence of LAE. Methods: Sufficient preoperative and postoperative follow-up clinical and imaging feature data for patients treated with TEVAR in the First Affiliated Hospital of Nanjing Medical University from January 2018 to December 2020 were collected. A univariate analysis and multivariable logistic regression analysis were used to find potential risk factors of LAE. Results: Ninety-six patients were finally included in this study. The mean age was 54.5 ± 11.7 years and 85 (88.5%) were male. LAE occurred in 15 (15.6%) of 96 patients after TEVAR. Two preoperative factors showed strong associations with LAE according to the multivariable logistic regression analysis: preoperative partial thrombosis of the FL (OR = 10.989 [2.295–48.403]; p = 0.002) and the maximum descending aortic diameter (OR = 1.385 [1.100–1.743] per mm increase; p = 0.006). Conclusions: Preoperative partial thrombosis of the FL and an increase in the maximum aortic diameter are strongly associated with late aortic expansion. Additional interventions of the FL may help to improve the prognosis of patients with the high risk of late aortic expansion.

Objectives: Calcific aortic valve disease (CAVD) is most common in the aging population and is without effective medical treatments. Brain and muscle ARNT-like 1 (BMAL1) is related to calcification. It has unique tissue-specific characteristics and plays different roles in different tissues’ calcification processes. The purpose of the present study is to explore the role of BMAL1 in CAVD. Methods: The protein levels of BMAL1 in normal and calcified human aortic valves and valvular interstitial cells (VICs) isolated from normal and calcified human aortic valves were checked. HVICs were cultured in osteogenic medium as an in vitro model, and BMAL1 expression and location were detected. TGF-β and RhoA/ROCK inhibitors and RhoA-siRNA were applied to detect the mechanism underlying the source of BMAL1 during HVICs’ osteogenic differentiation. ChIP was applied to check whether BMAL1 could directly interact with the runx2 primer CPG region, and the expression of key proteins involved in the TNF signaling pathway and NF-κ B pathway was tested after silencing BMAL1. Results: In this study, we found that BMAL1 expression was elevated in calcified human aortic valves and VICs isolated from calcified human aortic valves. Osteogenic medium could promote BMAL1 expression in HVICs and the knockdown of BMAL1 induced the inhibition of HVICs’ osteogenic differentiation. Furthermore, the osteogenic medium promoting BMAL1 expression could be blocked by TGF-β and RhoA/ROCK inhibitors and RhoA-siRNA. Meanwhile, BMAL1 could not bind with the runx2 primer CPG region directly, but knockdown of BMAL1 led to decreased levels of P-AKT, P-IκBα, P-p65 and P-JNK. Conclusions: Osteogenic medium could promote BMAL1 expression in HVICs through the TGF-β/RhoA/ROCK pathway. BMAL1 could not act as a transcription factor, but functioned through the NF-κ B/AKT/MAPK pathway to regulate the osteogenic differentiation of HVICs.

In this paper we develop a new sixth-order finite difference central weighted essentially non-oscillatory (WENO) scheme with Z-type nonlinear weights for nonlinear degenerate parabolic equations. The centered polynomial is introduced for the WENO reconstruction in order to avoid the negative linear weights. We choose the Z-type nonlinear weights based on the $L^2$-norm smoothness indicators, yielding the new WENO scheme with more accurate resolution. It is also confirmed that the proposed central WENO scheme with the devised nonlinear weights achieves sixth order accuracy in smooth regions. One- and two-dimensional numerical examples are presented to demonstrate the improved performance of the proposed central WENO scheme.

Camera-equipped mobile devices are encouraging people to take more photos and the development and growth of social networks is making it increasingly popular to share photos online. When objects appear in overlapping Fields Of View (FOV), this means that they are drawing much attention and thus indicates their popularity. Successfully discovering and locating these objects can be very useful for many applications, such as criminal investigations, event summaries, and crowdsourcing-based Geographical Information Systems (GIS). Existing methods require either prior knowledge of the environment or intentional photographing. In this paper, we propose a seamless approach called “Spotlight”, which performs passive localization using crowdsourced photos. Using a graph-based model, we combine object images across multiple camera views. Within each set of combined object images, a photographing map is built on which object localization is performed using plane geometry. We evaluate the system's localization accuracy using photos taken in various scenarios, with the results showing our approach to be effective for passive object localization and to achieve a high level of accuracy.

With the development of multimedia and computer graphics technologies, virtual reality (VR) is attracting more and more attention from both the academic communities and industrial companies. A head-mounted display (HMD) is the core equipment of VR. It envelops the entire sight of the wearer and reacts to some specific actions, mainly the head movement. Different from common video watching or game playing, VR poses the strict requirement of immersion so interaction methods need to be carefully designed. The hotword-based interaction as a typical hands-free method is very suitable for VR scenarios. However, the traditional hotword detection methods use a microphone to permit audio signal analysis. They not only incur significant recording overheads but are also susceptible to the surrounding noises. Instead of using the audio signals, we propose a motion-based hotword detection method called Alohomora. A multivariate time series (MTS) classification is formulated for processing the sensor data from multiple dimensions and types of motion sensors. We use a word extraction method for extracting and selecting patterns from MTS of motion data. Then, a classification model is trained using those discriminative patterns and finally the hotword can be detected in time. Alohomora is purely based on the motion sensors in HMDs without using any extra components such as microphone. As head tracking is always necessary in VR applications themselves, the overhead of Alohomora is nearly negligible. Finally, through extensive experiments, the final detection accuracy of Alohomora can exceed 90%.

Video streaming takes up an increasing proportion of network traffic nowadays. Dynamic adaptive streaming over HTTP (DASH) becomes the de facto standard of video streaming and it is adopted by Youtube, Netflix, and so on. Despite of the popularity, network traffic during video streaming shows an identifiable pattern which brings threat to user privacy. In this paper, we propose a video identification method using network traffic while streaming. Though there is bitrate adaptation in DASH streaming, we observe that the video bitrate trend remains relatively stable because of the widely used variable bit-rate (VBR) encoding. Accordingly, we design a robust video feature extraction method for eavesdropped video streaming traffic. Meanwhile, we design a VBR-based video fingerprinting method for candidate video set which can be built using downloaded video files. Finally, we propose an efficient partial matching method for computing similarities between video fingerprints and streaming traces to derive video identities. We evaluate our attack method in different scenarios for various video content, segment lengths, and quality levels. The experimental results show that the identification accuracy can reach up to 90% using only three-minute continuous network traffic eavesdropping.

Calcification of the bicuspid aortic valve (BAV) involves differential expression of various RNA genes, which is achieved through complex regulatory networks that are controlled in part by transcription factors and microRNAs. We previously found that miR-195-5p regulates the osteogenic differentiation of valvular interstitial cells (VICs) by targeting the TGF-β pathway. However, the transcriptional regulation of miR-195-5p in calcified BAV patients is not yet clear. In this study, stenotic aortic valve tissues from patients with BAVs and tricuspid aortic valves (TAVs) were collected. Candidate transcription factors of miR-195-5p were predicted by bioinformatics analysis and tested in diseased valves and in male porcine VICs. SP2 gene expression and the corresponding protein levels in BAV were significantly lower than those in TAV, and a low SP2 expression level environment in VICs resulted in remarkable increases in RNA expression levels of RUNX2, BMP2, collagen 1, MMP2, and MMP9 and the corresponding proteins. ChIP assays revealed that SP2 directly bound to the transcription promoter region of miR-195-5p. Cotransfection of SP2 shRNA and a miR-195-5p mimic in porcine VICs demonstrated that SP2 repressed SMAD7 expression via miR-195-5p, while knockdown of SP2 increased the mRNA expression of SMAD7 and the corresponding protein and attenuated Smad 2/3 expression. Immunofluorescence staining of diseased valves confirmed that the functional proteins of osteogenesis differentiation, including RUNX2, BMP2, collagen 1, and osteocalcin, were overexpressed in BAVs. In Conclusion, the transcription factor Sp2 is expressed at low levels in VICs from BAV patients, which has a negative impact on miR-195-5p expression by binding its promoter region and partially promotes calcification through a SMAD-dependent pathway.

Calcified aortic valve disease (CAVD) is a cardiovascular disease closely related to cardiovascular morbidity and mortality. Osteogenesis differentiation of valvular interstitial cells (VICs) is the key process of CAVD. In this study, we investigated whether the circulating exosomes participated in the pathogenesis and progression of CAVD and explored the underlying mechanism. We constructed the CAVD model in rats to perform in-vivo experiments, and isolated the VICs to perfume in-vitro studies. A series of methods were used including exosomes extraction and identification, RNA sequencing, ALP activity assay, alizarin red staining, qRT-PCR, western blot, and luciferase reporter assay. RNA sequencing showed that the circulating exosomes from CAVD patients and the normal people exhibited aberrant long non-coding RNA level, among which RMST was significantly upregulated in the CAVD-derived circulating exosomes and in the calcified aortic valve tissues. ALP activity assay and alizarin red staining showed that RMST promoted the VICs calcification. Luciferase reporter assay indicated that RMST acted as the miR-195-5p sponge, and miR-195-5p could target the 3’UTR of Smad7. Further functional experiments revealed that RMST was enriched in the circulating exosomes, leading to the upregulation of Smad7 in through sponging miR-195-5p to promote osteogenic differentiation in VICs. Moreover, adipose-derived exosomes showed the same effect as the CAVD-derived circulating exosomes. In conclusion, we found that circulating exosomes from CAVD patients promoted the VICs calcification through delivering the lncRNA RMST which acted as the miR-195-5p sponge to regulate the Smad7 expression. These results provided a new understanding of the molecular mechanism of the progression of CAVD. Funding: This work was supported by National Natural Science Foundation of China (grant no. 81974033). Declaration of Interest: None to declare. Ethical Approval: The present research program had been reviewed and approved by the Ethics Committee of The First Affiliated Hospital of Nanjing Medical University.

Many cloud platforms emerge to meet urgent requirements for large-volume personal image store, sharing and search. Though most would agree that images contain rich sensitive information (e.g., people, location and event) and people’s privacy concerns hinder their participation into untrusted services, today’s cloud platforms provide little support for image privacy protection. Facing large-scale images from multiple users, it is extremely challenging for the cloud to maintain the index structure and schedule parallel computation without learning anything about the image content and indices. In this work, we introduce a novel system PIC: A Privacy-preserving Image search system on Cloud, which is a step towards feasible cloud services which provide secure content-based large-scale image search with fine-grained access control. Users can search on others’ images if they are authorized by the image owners. Majority of the computationally intensive jobs are handled by the cloud, and a querier can now simply send the query and receive the result. Specially, to deal with massive images, we design our system suitable for distributed and parallel computation and introduce several optimizations to further expedite the search process. Our security analysis and prototype system evaluation results show that PIC successfully protects the image privacy at a low cost of computation and communication.

The classical finite difference methods for solving initial value problems are based on the polynomial interpolation of the unknown solution. The expected order of convergence of every classical method is fixed regardless of the smoothness of the unknown solution. However, if the local derivatives of the solution are known or can be estimated to a certain order, such information could be used to improve the order of convergence of the local truncation error and further the order of accuracy of the global error. The aim of this paper is to utilize the radial basis function (RBF) interpolation to modify several finite difference methods and thus enhance the performance in terms of local convergence. In this work, we choose multiquadric RBFs as the interpolation basis and find the conditions of the shape parameter that could enhance accuracy. The rate of convergence of each modified method is at least the same as the original one and can be further improved by making the local truncation error vanish. In that sense, the proposed adaptive method is optimal. Compared to the linear multistep methods, the proposed adaptive RBF multistep methods exhibit higher order convergence. We provide the analysis of consistency and stability with numerical results that support our claims.

An explicit error inhibiting block one-step method was developed by Ditkowski and Gottlieb in 2017. It is motivated by a class of one-step methods described in Shampine and Watts (Math Comp 23:731–740, 1969), which takes initial s step values to generate the next s step values at each step. The error inhibiting method shares the form of the diagonally implicit multistage integration method of type 3 introduced in Butcher (Appl Numer Math 11:347–363, 1993). With the explicit error inhibiting scheme, the convergence of the global error is one order higher than that of the local truncation error, while in general the global error decays with the same order as the local truncation error. In this work, we improve the explicit error inhibiting block one-step method in order to further enhance the convergence and accuracy of the method. The main idea is to adopt the radial basis functions as a reconstruction basis replacing the polynomial basis. The numerical results confirm that the proposed method is efficient in providing enhanced order of accuracy.

Singular perturbation problem cannot be solved without oscillations by the classical finite difference methods on the uniform grid unless sufficient resolution is employed. In this note we use the Gaussian radial basis function (RBF) finite difference method and show that it is possible for the finite difference method to yield non-oscillatory and accurate solutions to the problem for any degree of resolution on uniform grids with the adaptivity of the shape parameter of the RBFs. Even with a highly small number of grid points, non-oscillatory and accurate solutions to the singular perturbation problem can be obtained with the optimal value of the shape parameter. We show that even the error vanishes for some cases. We also provide a possible suggestion to choose the optimal shape parameter that minimizes the error using the total variation norm of the numerical solution.

Adaptive radial basis function (RBF) methods have been developed recently in Gu and Jung (2020) based on the multiquadric (MQ) RBFs for solving initial value problems (IVPs). The proposed adaptive RBF methods utilize the free parameter in order to adaptively enhance the local convergence of the numerical solution. Methods pertaining to the polynomial interpolation yield only fixed rate of convergence regardless of the solution smoothness while the proposed methods use the smoothness of the solution, given in derivatives of the solution, to control the rate of convergence. In this paper, for the completion of the development of the adaptive RBF methods, we develop various adaptive Gaussian RBF methods for solving IVPs by modifying the classical solvers such as the Euler’s method, midpoint method, Adams–Bashforth method and Adams–Moulton method by replacing the polynomial basis with the Gaussian RBFs. For each development, we compare the performance with the adaptive MQ-RBF methods and explain when and why the adaptive Gaussian methods are better or not than the MQ-RBF ones. We provide the collection of modifications with the MQ and Gaussian RBFs. We also provide the stability regions for the adaptive Gaussian methods. Numerical results confirm that the adaptivity enhances accuracy and convergence and also show the differences and similarities between MQ and Gaussian RBFs in their performance — we found that the adaptive MQ-RBF method has larger stability region than the Gaussian RBF method. Both MQ and Gaussian RBF methods yield the desired order of convergence while the superiority of one method to the other depends on the method and the problem considered.

Video streaming takes up an increasing proportion of network traffic nowadays. Dynamic Adaptive Streaming over HTTP (DASH) becomes the de facto standard of video streaming and it is adopted by Youtube, Netflix, etc. Despite of the popularity, network traffic during video streaming shows identifiable pattern which brings threat to user privacy. In this paper, we propose a video identification method using network traffic while streaming. Though there is bitrate adaptation in DASH streaming, we observe that the video bitrate trend remains relatively stable because of the widely used Variable Bit-Rate (VBR) encoding. Accordingly, we design a robust video feature extraction method for eavesdropped video streaming traffic. Meanwhile, we design a VBR based video fingerprinting method for candidate video set which can be built using downloaded video files. Finally, we propose an efficient partial matching method for computing similarities between video fingerprints and streaming traces to derive video identities. We evaluate our attack method in different scenarios for various video content, segment lengths and quality levels. The experimental results show that the identification accuracy can reach up to 90 % using only three-minute continuous network traffic eavesdropping.

Autophagy regulates the metabolism, survival and function of numerous types of cell, including cells that comprise the cardiovascular system. The dysfunction of autophagy has been demonstrated in atherosclerosis, restenotic lesions and hypertensive vessels. As a member of the Ras GTPase superfamily, Rab7 serves a significant role in the regulation of autophagy. The present study evaluated how Rab7 affects the proliferation and invasion, and phenotypic transformations of aortic dissection (AD) smooth muscle cells (SMCs) via autophagy. Rab7 was overexpressed in AD tissues and the percentage of synthetic human aortic SMCs (HASMCs) was higher in AD tissues compared with NAD tissues. Downregulation of Rab7 decreased cell growth, reduced the number of invasive cells and decreased the percentage cells in the G1 phase. Autophagy of HASMCs was inhibited following Rab7 knockdown. Inhibition of autophagy with 3‑methyladenine or Rab7 knockdown suppressed the phenotypic conversion of contractile to synthetic HASMCs. The action of Rab7 may be mediated by inhibiting the Ras/Raf/mitogen‑activated protein kinase (MAPK) kinase (MEK)/extracellular signal related kinase (ERK) signaling pathway. In conclusion, the results revealed that Rab7‑mediated autophagy regulated the behavior of SMCs and the phenotypic transformations in AD via activation of the Ras/Raf/MEK/ERK signaling pathway. The findings of the present study may improve understanding of the role Rab7 in the molecular etiology of AD and suggests the application of Rab7 as a novel therapeutic target in the treatment of human AD.

With the growing popularity of Virtual Reality (VR), people spend more and more time wearing Head-Mounted Display (HMD) for an immersive experience. HMD is physically attached on wearer’s head so that head motion can be tracked. We find it can also detect subtle movement of facial muscles which is strongly related to speech according to the mechanism of phonation. Inspired by this observation, we propose NonAuditory Speech Recognition (NASR). It uses motion sensor for recognizing spoken words. Different from most prior work of speech recognition using microphone to capture audio signal for analysis, NASR is resistant to acoustic noise of surroundings because of its nonauditory mechanism. Without using microphone, it consumes less power and requires no special permissions in most operating systems. Besides, NASR can be seamlessly integrated into existing speech recognition systems. Through extensive experiments, NASR can get up to 90.97% precision with 82.98% recall rate for speech recognition.

Background Despite the successful creation of complex lesion sets during hybrid ablation (HA), reoccurrence of atrial fibrillation (AF), and/or atrial arrhythmia and procedural complications still occur. The main objective of this study was to compare the efficacy and safety between HA and transcatheter ablation (TA). Methods We searched Pubmed, Embase, and the Cochrane Central Register of Controlled Trials (CENTRAL) database up to October 2017. Studies that satisfied our predefined inclusion criteria were included. Of the 894 records, 4 studies encompassing 331 patients were included in our study. We assessed pooled data using random-effect or fixed-effect model. The main endpoint was freedom of atrial arrhythmia after follow-up duration, secondary results were procedure time and intraoperative and postoperative adverse events. Similarly, tertiary outcomes were endocardial time, fluoroscopy time, and postoperative hospitalization. Results Compared with TA, HA treatment through mini-thoracotomy access improved superiority in freedom of atrial arrhythmia after follow-up duration (odds ratio [OR] = 6.67, 95% confidence interval [CI]: 2.63-16.90), but HA increased the incidence of intraoperative and postoperative adverse events for AF patients (OR = 2.98, 95% CI: 1.30-6.83). HA through either mini-thoracotomy or transdiaphragmatic/subxiphoid access had longer procedure time and postoperative hospitalization than TA. However, endocardial time was shorter than TA. Conclusions For AF patients, HA possessed of an overall superior outcome using mini-thoracotomy way to TA. Although HA had longer procedure time, it yielded a reduction in endocardial time. Meanwhile, we should pay attention to the significantly high risk of intraoperative and postoperative adverse events that the HA generated.