The role of epicardial fat radiomic profiles for atrial fibrillation identification and recurrence risk with coronary CT angiography.

OBJECTIVES: Fat radiomic profile (FRP) was a promising imaging biomarker for identifying increased cardiac risk. We hypothesize FRP can be extended to fat regions around pulmonary veins (PV), left atrium (LA), and left atrial appendage (LAA) to investigate their usefulness in identifying atrial fibrillation (AF) and the risk of AF recurrence. METHODS: We analysed 300 individuals and grouped patients according to the occurrence and types of AF. We used receiver operating characteristic and survival curves analyses to evaluate the value of imaging biomarkers, including fat attenuation index (FAI) and FRP, in distinguishing AF from sinus rhythm and predicting post-ablation recurrence. RESULTS: FRPs from AF-relevant fat regions showed significant performance in distinguishing AF and non-AF with higher AUC values than FAI (peri-PV: FRP = 0.961 vs FAI = 0.579, peri-LA: FRP = 0.923 vs FAI = 0.575, peri-LAA: FRP = 0.900 vs FAI = 0.665). FRPs from peri-PV, peri-LA, and peri-LAA were able to differentiate persistent and paroxysmal AF with AUC values of 0.804, 0.819, and 0.694. FRP from these regions improved AF recurrence prediction with an AUC of 0.929, 0.732, and 0.794. Patients with FRP cut-off values of ≥0.16, 0.38, and 0.26 had a 7.22-, 5.15-, and 4.25-fold higher risk of post-procedure recurrence, respectively. CONCLUSIONS: FRP demonstrated potential in identifying AF, distinguishing AF types, and predicting AF recurrence risk after ablation. FRP from peri-PV fat depot exhibited a strong correlation with AF. Therefore, evaluating epicardial fat using FRP was a promising approach to enhance AF clinical management. ADVANCES IN KNOWLEDGE: The role of epicardial adipose tissue (EAT) in AF had been confirmed, we focussed on the relationship between EAT around pulmonary arteries and LAA in AF which was still unknown. Meanwhile, we used the FRP to excavate more information of EAT in AF.

Effect of Vigileo/FloTrac System-Guided Aggressive Hydration in Acute Myocardial Infarction Patients to Prevent Contrast-Induced Nephropathy After Urgent Percutaneous Coronary Intervention.

Tailored hydration strategies appear to provide an effective solution for preventing contrast-induced nephropathy (CIN) after percutaneous coronary intervention (PCI). The Vigileo/FloTrac system could predict the patients' fluid responsiveness and tolerance to hydration. This prospective multicenter, randomized controlled, open-label study evaluated the efficacy of aggressive hydration guided by the Vigileo/FloTrac system for CIN prevention in patients with acute myocardial infarction (AMI). This trial enrolled patients with AMI undergoing urgent PCI, and these patients were randomized (1:1) to receive either aggressive hydration guided by Vigileo/FloTrac system (intervention group) or general hydration (control group). Patients with AMI in the intervention group received a loading dose of saline, and the hydration speed was adjusted according to the change of Vigileo/FloTrac index. The primary end point is CIN, which was defined as a >25% or >0.5 mg/100 ml increase in serum creatinine compared with baseline during the first 72 hours after urgent PCI. This trial was registered in ClinicalTrials.gov (NCT04382313). A total of 344 patients with AMI were enrolled and randomized in our trial, and the baseline characteristics, including risk factors of CIN, of the Vigileo/FloTrac-guided hydration group (n = 173) and control group (n = 171) were well balanced (all p >0.05). The total hydration volume in Vigileo/FloTrac-guided hydration group was significantly much more than control group (1,910 ± 600 vs 440 ± 90 ml, p <0.001). The incidence of CIN in the Vigileo/FloTrac-guided hydration group was significantly decreased than that in the control group (12.1% [21/173] vs 22.2% [38/171], p = 0.013). There was not significantly different in the incidence of acute heart failure after PCI (9.2% [16/173] vs 7.6% [13/171], p = 0.583). The incidence of main adverse cardiovascular events in the Vigileo/FloTrac-guided hydration group was lower than that in the control group but without statistically difference (30 events [17.3%] vs 38 events [22.2%], p = 0.256). In conclusion, Vigileo/FloTrac system-guided aggressive hydration could effectively decrease the risk of CIN for patients with AMI undergoing urgent PCI and avoid attack of acute heart failure at the same time.

IntraCoronary Artery Retrograde Thrombolysis vs. Thrombus Aspiration in ST-Segment Elevation Myocardial Infarction: Study Protocol for a Randomized Controlled Trial.

Background: Type 2 diabetes (T2DM) is a major risk factor for myocardial infarction. Thrombus aspiration was considered a good way to deal with coronary thrombus in the treatment of acute myocardial infarction. However, recent studies have found that routine thrombus aspiration is not beneficial. This study is designed to investigate whether intracoronary artery retrograde thrombolysis (ICART) is more effective than thrombus aspiration or percutaneous transluminal coronary angioplasty (PTCA) in improving myocardial perfusion in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PPCI). Methods/Design: IntraCoronary Artery Retrograde Thrombolysis (ICART) vs. thrombus aspiration or PTCA in STEMI trial is a single-center, prospective, randomized open-label trial with blinded evaluation of endpoints. A total of 286 patients with STEMI undergoing PPCI are randomly assigned to two groups: ICART and thrombus aspiration or PTCA. The primary endpoint is the incidence of >70% ST-segment elevation resolution. Secondary outcomes include distal embolization, myocardial blush grade, thrombolysis in myocardial infarction (TIMI) flow grade, and in-hospital bleeding. Discussion: The ICART trial is the first randomized clinical trial (RCT) to date to verify the effect of ICART vs. thrombus aspiration or PTCA on myocardial perfusion in patients with STEMI undergoing PPCI. Clinical Trial Registration: [https://www.chictr.org.cn/], identifier [ChiCTR1900023849].

Effects of Nicorandil Administration on Infarct Size in Patients With ST-Segment-Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention: The CHANGE Trial.

Background Nicorandil was reported to improve microvascular dysfunction and reduce reperfusion injury when administered before primary percutaneous coronary intervention. In this multicenter, prospective, randomized, double-blind clinical trial (CHANGE [Effects of Nicorandil Administration on Infarct Size in Patients With ST-Segment-Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention]), we investigated the effects of nicorandil administration on infarct size in patients with ST-segment-elevation myocardial infarction treated with primary percutaneous coronary intervention. Methods and Results A total of 238 patients with ST-segment-elevation myocardial infarction were randomized to receive intravenous nicorandil (n=120) or placebo (n=118) before reperfusion. Patients in the nicorandil group received a 6-mg intravenous bolus of nicorandil followed by continuous infusion at a rate of 6 mg/h. Patients in the placebo group received the same dose of placebo. The predefined primary end point was infarct size on cardiac magnetic resonance (CMR) imaging performed at 5 to 7 days and 6 months after reperfusion. CMR imaging was performed in 201 patients (84%). Infarct size on CMR imaging at 5 to 7 days after reperfusion was significantly smaller in the nicorandil group compared with the placebo (control) group (26.5±17.1 g versus 32.4±19.3 g; P=0.022), and the effect remained significant on long-term CMR imaging at 6 months after reperfusion (19.5±14.4 g versus 25.7±15.4 g; P=0.008). The incidence of no-reflow/slow-flow phenomenon during primary percutaneous coronary intervention was much lower in the nicorandil group (9.2% [11/120] versus 26.3% [31/118]; P=0.001), and thus, complete ST-segment resolution was more frequently observed in the nicorandil group (90.8% [109/120] versus 78.0% [92/118]; P=0.006). Left ventricular ejection fraction on CMR imaging was significantly higher in the nicorandil group than in the placebo group at both 5 to 7 days (47.0±10.2% versus 43.3±10.0%; P=0.011) and 6 months (50.1±9.7% versus 46.4±8.5%; P=0.009) after reperfusion. Conclusions In the present trial, administration of nicorandil before primary percutaneous coronary intervention led to improved myocardial perfusion grade, increased left ventricular ejection fraction, and reduced myocardial infarct size in patients with ST-segment-elevation myocardial infarction. Registration URL: http://www.clinicaltrials.gov. Unique identifier: NCT03445728.

Intracoronary artery retrograde thrombolysis combined with percutaneous coronary interventions for ST-segment elevation myocardial infarction complicated with diabetes mellitus: A case report and literature review.

Background: The management of a large thrombus burden in patients with acute myocardial infarction and diabetes is still a worldwide problem. Case presentation: A 74-year-old Chinese woman presented with ST-segment elevation myocardial infarction (STEMI) complicated with diabetes mellitus and hypertension. Angiography revealed massive thrombus formation in the mid-segment of the right coronary artery leading to vascular occlusion. The sheared balloon was placed far from the occlusion segment and urokinase (100,000 u) was administered for intracoronary artery retrograde thrombolysis, and thrombolysis in myocardial infarction (TIMI) grade 3 blood flow was restored within 7 min. At last, one stent was accurately implanted into the culprit's vessel. No-reflow, coronary slow flow, and reperfusion arrhythmia were not observed during this process. Conclusion: Intracoronary artery retrograde thrombolysis (ICART) can be effectively and safely used in patients with STEMI along with diabetes mellitus and hypertension, even if the myocardial infarction exceeds 12 h (REST or named ICART ClinicalTrials.gov number, ChiCTR1900023849).

Intracoronary artery retrograde thrombolysis for ST-segment elevation myocardial infarction with a tortuous coronary artery: A case report and review of the literature.

Background: How to deal with large thrombus burdens of culprit's blood vessel remains a great challenge in the treatment of acute myocardial infarction. Case presentation: A 32-year-old Chinese man was diagnosed with ST-segment elevation myocardial infarction (STEMI). Coronary angiography revealed that the distal end of a tortuous left circumflex was completely occluded by a large amount of thrombus. Cutted balloon-directed intracoronary artery retrograde thrombolysis (ICART) with urokinase led to the restoration of coronary blood flow. Because there was no obvious plaque rupture or artery stenosis in the coronary artery, it was only dilated, and no stent was implanted. Conclusion: Cutted balloon-directed ICART can be performed effectively and safely in some STEMI patients with tortuous coronary vessels and large thrombus. (REST or named ICART ClinicalTrials.gov number, ChiCTR1900023849).

From Noise Addition to Denoising: A Self-Variation Capture Network for Point Cloud Optimization.

Point clouds obtained from 3D scanners are often noisy and cannot be directly used for subsequent high-level tasks. In this paper, we propose a novel point cloud optimization method capable of denoising and homogenizing point clouds. Our idea is based on the assumption that the noise is generally much smaller than the effective signal. We perform noise perturbation on the noisy point cloud to get a new noisy point cloud, called self-variation point cloud. The noisy point cloud and self-variation point cloud have different noise distribution, but the same point cloud distribution. We compute the potential commonality between two noisy point clouds to obtain a clean point cloud. To implement our idea, we propose a Self-Variation Capture Network (SVCNet). We perturb the point cloud features in the latent space to obtain self-variation feature vectors, and capture the commonality between two noisy feature vectors through the feature aggregation and averaging. In addition, an edge constraint module is introduced to suppress low-pass effects during denoising. Our denoising method does not take into account the noise characteristics, and can filter the drift noise located on the underlying surface, resulting in a uniform distribution of the generated point cloud. The experimental results show that our algorithm outperforms the current state-of-the-art algorithms, especially in generating more uniform point clouds. In addition, extended experiments demonstrate the potential of our algorithm for point clouds upsampling.

Effects of nicorandil on myocardial infarct size in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention: study design and protocol for the randomized controlled trial.

Previous studies have shown that nicorandil has a protective effect on cardiomyocytes. However, there is no study to investigate whether perioperative intravenous nicorandil can further reduce the myocardial infarct size in patients with ST-segment elevation myocardial infarction (STEMI) compared to the current standard of percutaneous coronary intervention (PCI) regimen. The CHANGE (China-Admini stration of Nicorandil Group) study is a multicenter, prospective, randomized, double-blind and parallel-controlled clinical study of STEMI patients undergoing primary PCI in China, aiming to evaluate the efficacy and safety of intravenous nicorandil in ameliorating the myocar dial infarct size in STEMI patients undergoing primary PCI and provide evidence-based support for myocardial protection strategies of STEMI patients.

Sitagliptin attenuates the progression of coronary atherosclerosis in patients with coronary disease and type 2 diabetes.

BACKGROUND AND AIMS: Type 2 diabetes mellitus (T2DM) is a well-recognized independent risk factor for ASCVD, the aim of this study was to investigate the effects of a dipeptidyl peptidase-4 inhibitor, sitagliptin, on prevention of progression of coronary atherosclerosis assessed by three-dimensional quantitative coronary angiography (3D-QCA) in T2DM patients with coronary artery disease (CAD). METHODS: This was a prospective, randomized, double-center, open-label, blinded end point, controlled 18-month study in patients with CAD and T2DM. A total of 149 patients, who had at least 1 atherosclerotic plaque with 20%-80% luminal narrowing in a coronary artery, and had not undergone intervention during a clinically indicated coronary angiography or percutaneous coronary intervention, were randomized to sitagliptin group (n = 74) or control group (n = 75). Atherosclerosis progression was measured by repeat 3D-QCA examination in 88 patients at study completion. The primary outcome was changes in percent atheroma volume (PAV) from baseline to study completion measured by 3D-QCA. Secondary outcomes included change in 3D-QCA-derived total atheroma volume (TAV) and late lumen loss (LLL). RESULTS: The primary outcome of PAV increased of 1.69% (95%CL, -0.8%-4.2%) with sitagliptin and 5.12% (95%CL, 3.49%-6.74%) with the conventional treatment (p = 0.023). The secondary outcome of change in TAV in patients treated with sitagliptin increased of 6.45 mm3 (95%CL,-2.46 to 6.36 mm3) and 9.45 mm3 (95%CL,-4.52 to 10.14 mm3) with conventional treatment (p = 0.023), however, no significant difference between groups was observed (p = 0.175). Patients treated with sitagliptin had similar LLL as compared with conventional antidiabetics (-0.06, 95%CL, -0.22 to 0.03 vs. -0.08, -0.23 to -0.03 mm, p = 0.689). CONCLUSIONS: In patients with type 2 diabetes and coronary artery disease, treatment with sitagliptin resulted in a significantly lower rate of progression of coronary atherosclerosis compared with conventional treatment.

Female Fertility Has a Negative Relationship With Longevity in Chinese Oldest-Old Population: A Cross-Sectional Study.

Background: Despite research efforts in this field for more than a century, the relationship between female fertility and longevity is unclear. This study was designed to investigate this relationship in Chinese oldest-old population. Methods: The China Hainan Centenarian Cohort Study was performed in 18 cities and counties of Hainan. A total of 1,226 females, including 758 centenarian women and 468 women aged 80-99 years, were enrolled in this study. Using a standardized protocol, in-person interviews and blood analyses were conducted by a well-trained research team through home visits. Results: Centenarian women had significantly lower number of children (NOC) and higher initial childbearing age (ICA) and last childbearing age (LCA) than women aged 80-99 years (p < 0.05 for all). Multivariate logistic regression analysis showed that NOC and testosterone (T) levels were positively associated with women aged 80-99 years, when centenarian women was considered as reference (p < 0.05 for all). ICA, LCA, and estradiol (E2) levels were negatively associated with women aged 80-99 years, when centenarian women was considered as reference (p < 0.05 for all). Conclusions: The centenarians had crucial characteristics of less and delayed childbearing, indicating a negative relationship between female fertility and longevity in Chinese oldest-old population. Serum E2 levels were positively associated and serum T levels were negatively associated with longevity. The less and late childbearing might be a significant factor of longevity, and successful aging might be promoted by reducing and delaying female childbearing.

Intracoronary arterial retrograde thrombolysis with percutaneous coronary intervention: a novel use of thrombolytic to treat acute ST-segment elevation myocardial infarction.

BACKGROUND: Clearance of coronary arterial thrombosis is necessary in patients with acute ST-segment elevation myocardial infarction (STEMI) undergoing urgent percutaneous coronary intervention (PCI). There is currently no highly-recommended method of thrombus removal during interventional procedures. We describe a new method for opening culprit vessels to treat STEMI: intracoronary arterial retrograde thrombolysis (ICART) with PCI. METHODS & RESULTS: Eight patients underwent ICART. The guidewire was advanced to the distal coronary artery through the occlusion lesion. Then, we inserted a microcatheter into the distal end of the occluded coronary artery over the guidewire. Urokinase (5-10 wu) mixed with contrast agents was slowly injected into the occluded section of the coronary artery through the microcatheter. The intracoronary thrombus gradually dissolved in 3-17 min, and the effect of thrombolysis was visible in real time. Stents were then implanted according to the characteristics of the recanalized culprit lesion to achieve full revascularization. One patient experienced premature ventricular contraction during vascular revascularization, and no malignant arrhythmias were seen in any patient. No reflow or slow flow was not observed post PCI. Thrombolysis in myocardial infarction flow grade and myocardial blush grade post-primary PCI was 3 in all eight patients. No patients experienced bleeding or stroke. CONCLUSIONS: ICART was accurate and effective for treating intracoronary thrombi in patients with STEMI in this preliminary study. ICART was an effective, feasible, and simple approach to the management of STEMI, and no intraprocedural complications occurred in any of the patients. ICART may be a breakthrough in the treatment of acute STEMI.

Feed-forward frequency offset estimation for 32-QAM optical coherent detection.

Due to the non-rectangular distribution of the constellation points, traditional fast Fourier transform based frequency offset estimation (FFT-FOE) is no longer suitable for 32-QAM signal. Here, we report a modified FFT-FOE technique by selecting and digitally amplifying the inner QPSK ring of 32-QAM after the adaptive equalization, which is defined as QPSK-selection assisted FFT-FOE. Simulation results show that no FOE error occurs with a FFT size of only 512 symbols, when the signal-to-noise ratio (SNR) is above 17.5 dB using our proposed FOE technique. However, the error probability of traditional FFT-FOE scheme for 32-QAM is always intolerant. Finally, our proposed FOE scheme functions well for 10 Gbaud dual polarization (DP)-32-QAM signal to reach 20% forward error correction (FEC) threshold of BER=2×10-2, under the scenario of back-to-back (B2B) transmission.

Hypotensive effects of renal denervation in spontaneously hypertensive rat based on ultrasonic contrast imaging.

BACKGROUND: Sympathetic nerves-fire rate is generally enhanced in some types of hypertension models. Renal sympathetic denervation(RSD) by the radiofrequency ablation was used to treat the hypertension has achieved curative effect.HTN-1 and HTN-2 trial reported catheter-based renal denervation may cause substantial and sustained blood-pressure reduction in patients with resistant hypertension. However, recent controlled HTN-3 trial questioned the BP lowering effect of Renal denervation treatment. The controversial results maybe arised from the incompleted RSD which implemented inside the renal artery. Now renal denervation therapy for resistant hypertension is in attractive and controversial status. Our aim is to define the hyotensive value of complete renal denervation in adult spontaneous hypertensive rats. METHODS: Male spontaneous hypertensive rats(SHR) aged 12 weeks were randomly selected for either unilateral renal artery sympathetic nerves ablation (URSNA), or conventional technique of renal denervation (CRD), or bilateral renal artery sympathetic nerves ablation (BRSNA) and sham operation. Blood pressure, sodium and water balance,serum reninangiotensin II and Norepinephrine concentration were measured during 20 weeks after renal denervation operation. Internal diameters of renal arteries and renal blood flow rate was tested by ultrasonic contrast imaging. RESULTS: The continued increased blood pressure in SHR was delayed and significantly reduced by conventional renal denervation over a period of 8 weeks. Both the bilateral and unilateral renal sympathetic nerve ablation procedure did not prevent the development of hypertension in SHR. The attenuation of hypertension was accompanied with the increase of urinary sodium excretion and depression of rennin angiotensin system (RAS). CONCLUSIONS: We concluded that renal denervation may not be an effective therapeutic method in the long-term control of hypertension in adult SHR.

Efficacy and safety outcomes of fractional flow reserve in guiding clinical therapy of non-ST-segment elevation myocardial infarction compared with angiography alone in elderly Chinese patients.

OBJECTIVE: Fractional flow reserve (FFR) is an innovative method for evaluating the physiological significance of a coronary stenosis, but its validity is less certain in patients with non-ST-segment elevation myocardial infarction (NSTEMI). It is important to assess whether FFR is effective and safe in patients, especially elderly Chinese patients, with NSTEMI. As the first one in China, the purpose of this study was to establish the efficacy and safety outcomes of FFR in guiding clinical therapy of NSTEMI compared with angiography alone in elderly Chinese patients. PATIENTS AND METHODS: This prospective randomized controlled study included 220 patients with NSTEMI older than 65 years. Patients were assigned in a ratio of 1:1 to the FFR-guided group and the angiography-guided group, and their outcomes were evaluated after 1 year of follow-up. RESULTS: The mean age of the patients was 70±3.6 years, and 69.6% were men. Baseline characteristics of the patients had no differences between the two groups (P>0.05 for all). No differences in adverse events, including major adverse cardiovascular event, major adverse cardiovascular and cerebrovascular event, cardiovascular death, nonfatal myocardial infarction, heart failure, stroke, transient ischemic attack, all-cause mortality, contrast nephropathy, and major bleeding, was observed between the two groups during the follow-up (P>0.05 for all). The number of patients receiving medical therapy alone in the FFR-guided group was significantly more than that in the angiography-guided group (P<0.05). CONCLUSION: Compared with angiography-guided standard therapy, FFR reduced the application of percutaneous coronary intervention and obtained similar outcomes, demonstrating that FFR was effective and safe in guiding clinical therapy of NSTEMI in elderly Chinese patients.

The mitochondrial calcium uniporter is involved in mitochondrial calcium cycle dysfunction: Underlying mechanism of hypertension associated with mitochondrial tRNA(Ile) A4263G mutation.

Recent studies have shown that the mitochondrial DNA mutations are involved in the pathogenesis of hypertension. Our previous study identified mitochondrial tRNA(Ile) A4263G mutation in a large Chinese Han family with maternally-inherited hypertension. This mutation may contribute to mitochondrial Ca(2+) cycling dysfuntion, but the mechanism is unclear. Lymphoblastoid cell lines were derived from hypertensive and normotensive individuals, either with or without tRNA(Ile) A4263G mutation. The mitochondrial calcium ([Ca(2+)]m) in cells from hypertensive subjects with the tRNA(Ile) A4263G mutation, was lower than in cells from normotension or hypertension without mutation, or normotension with mutation (P<0.05). Meanwhile, cytosolic calcium ([Ca(2+)]c) in hypertensive with mutation cells was higher than another three groups. After exposure to caffeine, which could increase the [Ca(2+)]c by activating ryanodine receptor on endoplasmic reticulum, [Ca(2+)]c/[Ca(2+)]m increased higher than in hypertensive with mutation cells from another three groups. Moreover, MCU expression was decreased in hypertensive with mutation cells compared with in another three groups (P<0.05). [Ca(2+)]c increased and [Ca(2+)]m decreased after treatment with Ru360 (an inhibitor of MCU) or an siRNA against MCU. In this study we found decreased MCU expression in hypertensive with mutation cells contributed to dysregulated Ca(2+) uptake into the mitochondria, and cytoplasmic Ca(2+) overload. This abnormality might be involved in the underlying mechanisms of maternally inherited hypertension in subjects carrying the mitochondrial tRNA(Ile) A4263G mutation.

Cauchy graph embedding based diffusion model for salient object detection.

Salient object detection has been a rather hot research topic recently, due to its potential applications in image compression, scene classification, image registration, and so forth. The overwhelming majority of existing computational models are designed based on computer vision techniques by using lots of image cues and priors. Actually, salient object detection is derived from the biological perceptual mechanism, and biological evidence shows that the spread of the spatial attention generates the object attention. Inspired by this, we attempt to utilize the emerging spread mechanism of object attention to construct a new computational model. A novel Cauchy graph embedding based diffusion (CGED) model is proposed to fulfill the spread process. Combining the diffusion model and attention prediction model, a salient object detection approach is presented through perceptually grouping the multiscale diffused attention maps. The effectiveness of the proposed approach is validated on the salient object dataset. The experimental results show that the CGED process can obviously improve the performance of salient object detection compared with the input spatial attention map, and the proposed approach can achieve performance comparable to that of state-of-the-art approaches.

Collaborative multicue fusion using the cross-diffusion process for salient object detection.

Salient object detection is very useful in a large variety of image and vision-related applications. A recent trend in salient object detection is to explore novel top-down visual cues and combine them with bottom-up saliency to improve the performance. However, a basic and important problem, i.e., how to effectively fuse multiple visual cues, has rarely been addressed in previous works. To this end, the paper presents a multicue fusion method using the cross-diffusion process (CDP) for salient object detection. The CDP algorithm is deployed to combine the affinity matrices constructed over individual visual cue channels, which is then embedded into a saliency propagation framework to accomplish salient object detection. Different from other multicue fusion strategies, our proposed approach allows for collaborative fusion, that is, the individual visual cues to be fused are able to interact and exchange information with each other during the fusion procedure, which can possibly correct the noise or corruption included in the individual visual cue channels, leading to more robust and effective fusion results. Intensive experiments on publicly available datasets demonstrate the effectiveness and superior performance of our proposed method.

Electrophysiological Characteristics of the LQT2 Syndrome Mutation KCNH2-G572S and Regulation by Accessory Protein KCNE2.

Mutations in hERG cause long QT syndrome type 2 which is characterized by a prolonged QT interval on electrocardiogram and predisposition to life-threatening ventricular tachyarrhythmia, syncope, and sudden death. hERG-G572S induces trafficking defects of hERG channel protein from Golgi to the plasma membrane and results in a dominant negative suppression of hERG current density. As an accessory ß subunit, KCNE2 promotes hERG migration from Golgi to cellular membrane. In this study, we investigated the rescue effect of KCNE2 in a G572S mutation of hERG. Transfection was performed into HEK293 cells. Patch clamp technique, western blotting analyses and confocal microscopic examination were used. Results showed that KCNE2 had a significantly enhanced effect on G572S mutation current. The increase of current was largest at KCNH2:KCNE2 of 1:3. Confocal images showed co-expressing G572S and KCNE2 could cause a substantial up-regulated membrane protein (155 kDa) expression. Expression of membrane protein accumulated markedly with increasing ratio of KCNH2:KCNE2. G572S defective mutant could be restored by both KCNE2 and lower temperature (27°C), which suggested that the lower temperature could be the favorable circumstances for the rescue function of KCNE2. In this study, we successfully set up "the action potential" on the HEK 293 cells by genetically engineered to express Kir2.1, Nav1.5, and Kv11.1, wherein on reaching over an excitation threshold by current injection. The results suggested that KCNE2 could shorten action potential duration which was prolonged by G572S. These findings described electrophysiological characteristics of the LQT2 syndrome mutation KCNH2-G572S and regulation by accessory protein KCNE2, and provided a clue about LQT2 and relative rescue mechanism.

A biologically-inspired framework for contour detection using superpixel-based candidates and hierarchical visual cues.

Contour detection has been extensively investigated as a fundamental problem in computer vision. In this study, a biologically-inspired candidate weighting framework is proposed for the challenging task of detecting meaningful contours. In contrast to previous models that detect contours from pixels, a modified superpixel generation processing is proposed to generate a contour candidate set and then weigh the candidates by extracting hierarchical visual cues. We extract the low-level visual local cues to weigh the contour intrinsic property and mid-level visual cues on the basis of Gestalt principles for weighting the contour grouping constraint. Experimental results tested on the BSDS benchmark show that the proposed framework exhibits promising performances to capture meaningful contours in complex scenes.

Method for pan-tilt camera calibration using single control point.

The pan-tilt (PT) camera is widely used in video surveillance systems due to its rotatable property and low cost. The rough output of a PT camera may not satisfy the demand of practical applications; hence an accurate calibration method of a PT camera is desired. However, high-precision camera calibration methods usually require sufficient control points not guaranteed in some practical cases of a PT camera. In this paper, we present a novel method to online calibrate the rotation angles of a PT camera by using only one control point. This is achieved by assuming that the intrinsic parameters and position of the camera are known in advance. More specifically, we first build a nonlinear PT camera model with respect to two parameters Pan and Tilt. We then convert the nonlinear model into a linear model according to sine and cosine of Tilt, where each element in the augmented coefficient matrix is a function of the single variable Pan. A closed-form solution of Pan and Tilt can then be derived by solving a quadratic equation of tangent of Pan. Our method is noniterative and does not need features matching; thus its time efficiency is better. We evaluate our calibration method on various synthetic and real data. The quantitative results demonstrate that the proposed method outperforms other state-of-the-art methods if the intrinsic parameters and position of the camera are known in advance.