90 research outputs found
DyTed: Disentangled Representation Learning for Discrete-time Dynamic Graph
Unsupervised representation learning for dynamic graphs has attracted a lot
of research attention in recent years. Compared with static graph, the dynamic
graph is a comprehensive embodiment of both the intrinsic stable
characteristics of nodes and the time-related dynamic preference. However,
existing methods generally mix these two types of information into a single
representation space, which may lead to poor explanation, less robustness, and
a limited ability when applied to different downstream tasks. To solve the
above problems, in this paper, we propose a novel disenTangled representation
learning framework for discrete-time Dynamic graphs, namely DyTed. We specially
design a temporal-clips contrastive learning task together with a structure
contrastive learning to effectively identify the time-invariant and
time-varying representations respectively. To further enhance the
disentanglement of these two types of representation, we propose a
disentanglement-aware discriminator under an adversarial learning framework
from the perspective of information theory. Extensive experiments on Tencent
and five commonly used public datasets demonstrate that DyTed, as a general
framework that can be applied to existing methods, achieves state-of-the-art
performance on various downstream tasks, as well as be more robust against
noise
YXQ-EQ Induces Apoptosis and Inhibits Signaling Pathways Important for Metastasis in Non-Small Cell Lung Carcinoma Cells
Background/Aims: Lung cancer is one of the most prevalent malignancies in the world. The 5-year survival rate for non-small cell lung cancer (NSCLC) patients is only approximately 15%, with metastasis as the primary cause of death. This study was aimed to investigate cytotoxic effect of external qi of Yan Xin Qigong (YXQ-EQ) toward human lung adenocarcinoma A549 cells as well as its effect on signaling pathways promoting migration, invasion and epithelial-to-mesenchymal transition (EMT) in A549 cells. Methods: Cytotoxic effect of YXQ-EQ was evaluated using MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt] and cologenic assays. Apoptosis of treated cells was determined by Annexin V/propidium iodide staining and flow cytometry analysis, while cell migration and invasion were determined using transwell assays and EMT was assessed by morphological changes in cells. Protein expression and phosphorylation were examined by immunoblot analyses. Results: YXQ-EQ induced apoptosis in A549 cells, resulting in a pronounced reduction in viability and clonogenic formation. This was associated with inhibition of phosphorylation of AKT and ERK1/2 and reduced expression of anti-apoptotic proteins BCL-xL, XIAP and survivin. Furthermore, YXQ-EQ inhibited EGF/EGFR signaling and EGF mediated migration and invasion of A549 cells. While TGF-β1 induced phosphorylation of SMAD2/3 and EMT in A549 cells, YXQ-EQ suppressed TGF-β/SMAD signaling and induced cell death in these cells in the presence of TGF-β1. Conclusion: Our findings suggest that YXQ-EQ could exert anti-lung cancer effects via inhibiting signaling pathways that are important for NSCLC cell survival and NSCLC metastasis
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EM-mosaic detects mosaic point mutations that contribute to congenital heart disease.
BackgroundThe contribution of somatic mosaicism, or genetic mutations arising after oocyte fertilization, to congenital heart disease (CHD) is not well understood. Further, the relationship between mosaicism in blood and cardiovascular tissue has not been determined.MethodsWe developed a new computational method, EM-mosaic (Expectation-Maximization-based detection of mosaicism), to analyze mosaicism in exome sequences derived primarily from blood DNA of 2530 CHD proband-parent trios. To optimize this method, we measured mosaic detection power as a function of sequencing depth. In parallel, we analyzed our cohort using MosaicHunter, a Bayesian genotyping algorithm-based mosaic detection tool, and compared the two methods. The accuracy of these mosaic variant detection algorithms was assessed using an independent resequencing method. We then applied both methods to detect mosaicism in cardiac tissue-derived exome sequences of 66 participants for which matched blood and heart tissue was available.ResultsEM-mosaic detected 326 mosaic mutations in blood and/or cardiac tissue DNA. Of the 309 detected in blood DNA, 85/97 (88%) tested were independently confirmed, while 7/17 (41%) candidates of 17 detected in cardiac tissue were confirmed. MosaicHunter detected an additional 64 mosaics, of which 23/46 (50%) among 58 candidates from blood and 4/6 (67%) of 6 candidates from cardiac tissue confirmed. Twenty-five mosaic variants altered CHD-risk genes, affecting 1% of our cohort. Of these 25, 22/22 candidates tested were confirmed. Variants predicted as damaging had higher variant allele fraction than benign variants, suggesting a role in CHD. The estimated true frequency of mosaic variants above 10% mosaicism was 0.14/person in blood and 0.21/person in cardiac tissue. Analysis of 66 individuals with matched cardiac tissue available revealed both tissue-specific and shared mosaicism, with shared mosaics generally having higher allele fraction.ConclusionsWe estimate that ~ 1% of CHD probands have a mosaic variant detectable in blood that could contribute to cardiac malformations, particularly those damaging variants with relatively higher allele fraction. Although blood is a readily available DNA source, cardiac tissues analyzed contributed ~ 5% of somatic mosaic variants identified, indicating the value of tissue mosaicism analyses
Fine-tuning of microglia polarization prevents diabetes-associated cerebral atherosclerosis
Diabetes increases the occurrence and severity of atherosclerosis. When plaques form in brain vessels, cerebral atherosclerosis causes thickness, rigidity, and unstableness of cerebral artery walls, leading to severe complications like stroke and contributing to cognitive impairment. So far, the molecular mechanism underlying cerebral atherosclerosis is not determined. Moreover, effective intervention strategies are lacking. In this study, we showed that polarization of microglia, the resident macrophage in the central nervous system, appeared to play a critical role in the pathological progression of cerebral atherosclerosis. Microglia likely underwent an M2c-like polarization in an environment long exposed to high glucose. Experimental suppression of microglia M2c polarization was achieved through transduction of microglia with an adeno-associated virus (serotype AAV-PHP.B) carrying siRNA for interleukin-10 (IL-10) under the control of a microglia-specific TMEM119 promoter, which significantly attenuated diabetes-associated cerebral atherosclerosis in a mouse model. Thus, our study suggests a novel translational strategy to prevent diabetes-associated cerebral atherosclerosis through in vivo control of microglia polarization
Reperfusion status and postoperative blood pressure in acute stroke patients after endovascular treatment
Background and purposeAn aggressive lowering of blood pressure (BP) could lead to neurological worsening, particularly of the area that has not been reperfused in acute stroke patients with large vessel occlusion (LVO). We sought to investigate the association of reperfusion status and BP course following mechanical thrombectomy (MT) with outcomes in LVO.Materials and methodsConsecutive patients with LVO treated with MT between Jan 2020 to Jun 2021 were enrolled in a retrospective cohort study. Hourly systolic BP (SBP) and diastolic BP (DBP) were recorded for 72 h following MT and maximum SBP and DBP levels were identified. The Extended Thrombolysis in Cerebral Infarction (eTICI) scale was used to assess reperfusion extent. LVO patients were stratified in 2 groups based on reperfusion status: complete reperfusion (eTICI 3) and incomplete reperfusion (eTICI 2b/c). Three-month functional independence was defined as a modified Rankin Scale score of 0–2.ResultsA total of 263 acute ischemic stroke patients with LVO were retrospectively evaluated. Complete reperfusion was achieved in 210 patients (79.8%). Post-MT maximum SBP over 160 mmHg was significantly related to worse functional outcome (38.1% vs. 55.7%, p = 0.006), higher likelihood of in-hospital mortality and 3-month mortality (19.0% vs. 6.9%, p = 0.004, 27.4% vs. 14.3%, p = 0.012). No statistical correlation was found between reperfusion status and blood pressure level (p > 0.05). In patients with complete reperfusion, patients with an average BP 120-140 mmHg tends to have worse functional outcome compared with 100-120 mmHg (OR = 1.77, 95%CI: 0.97–3.23, p = 0.061).ConclusionHigh maximum SBP levels following MT are associated with an increased likelihood of 3-month functional dependence and mortality. An average BP of 100–120 mmHg tends to have better functional independence in completely reperfused patients. The effect of intensive BP control on incomplete reperfusion still warrants further investigations
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EM-mosaic detects mosaic point mutations that contribute to congenital heart disease
Background
The contribution of somatic mosaicism, or genetic mutations arising after oocyte fertilization, to congenital heart disease (CHD) is not well understood. Further, the relationship between mosaicism in blood and cardiovascular tissue has not been determined.
Methods
We developed a new computational method, EM-mosaic (Expectation-Maximization-based detection of mosaicism), to analyze mosaicism in exome sequences derived primarily from blood DNA of 2530 CHD proband-parent trios. To optimize this method, we measured mosaic detection power as a function of sequencing depth. In parallel, we analyzed our cohort using MosaicHunter, a Bayesian genotyping algorithm-based mosaic detection tool, and compared the two methods. The accuracy of these mosaic variant detection algorithms was assessed using an independent resequencing method. We then applied both methods to detect mosaicism in cardiac tissue-derived exome sequences of 66 participants for which matched blood and heart tissue was available.
Results
EM-mosaic detected 326 mosaic mutations in blood and/or cardiac tissue DNA. Of the 309 detected in blood DNA, 85/97 (88%) tested were independently confirmed, while 7/17 (41%) candidates of 17 detected in cardiac tissue were confirmed. MosaicHunter detected an additional 64 mosaics, of which 23/46 (50%) among 58 candidates from blood and 4/6 (67%) of 6 candidates from cardiac tissue confirmed. Twenty-five mosaic variants altered CHD-risk genes, affecting 1% of our cohort. Of these 25, 22/22 candidates tested were confirmed. Variants predicted as damaging had higher variant allele fraction than benign variants, suggesting a role in CHD. The estimated true frequency of mosaic variants above 10% mosaicism was 0.14/person in blood and 0.21/person in cardiac tissue. Analysis of 66 individuals with matched cardiac tissue available revealed both tissue-specific and shared mosaicism, with shared mosaics generally having higher allele fraction.
Conclusions
We estimate that ~ 1% of CHD probands have a mosaic variant detectable in blood that could contribute to cardiac malformations, particularly those damaging variants with relatively higher allele fraction. Although blood is a readily available DNA source, cardiac tissues analyzed contributed ~ 5% of somatic mosaic variants identified, indicating the value of tissue mosaicism analyses
Endovascular treatment of acute ischemic stroke with a fully radiopaque retriever: A randomized controlled trial
ObjectiveThe Neurohawk retriever is a new fully radiopaque retriever. A randomized controlled non-inferiority trial was conducted to compare the Neurohawk and the Solitaire FR in terms of safety and efficacy. In order to evaluate the efficacy and safety of endovascular treatment in acute ischemic stroke (AIS) caused by intracranial atherosclerotic disease (ICAD) larger vessel occlusion (LVO), a sub-analysis was performed.MethodsAcute ischemic stroke patients aged 18–80 years with LVO in the anterior circulation were randomly assigned to undergo thrombectomy with either the Neurohawk or the Solitaire FR. The primary efficacy endpoint was successful reperfusion (mTICI 2b-3) rate by the allocated retriever. A relevant non-inferiority margin was 12.5%. Safety outcomes were symptomatic intracranial hemorrhage (sICH) and all-cause mortality within 90 days. Secondary endpoints included first-pass effect (FPE), modified FPE, and favorable outcomes at 90 days. In subgroup analysis, the patients were divided into the ICAD group and non-ICAD group according to etiology, and baseline characteristics, angiographic, and clinical outcomes were compared.ResultsA total of 232 patients were involved in this analysis (115 patients in the Neurohawk group and 117 in the Solitaire group). The rates of successful reperfusion with the allocated retriever were 88.70% in the Neurohawk group and 90.60% in the Solitaire group (95%CI of the difference, −9.74% to 5.94%; p = 0.867). There were similar results in FPE and mFPE in both groups. The rate of sICH seemed higher in the Solitaire group (13.16% vs. 7.02%, p = 0.124). All-cause mortality and favorable outcome rates were comparable as well. In subgroup analysis, 58 patients were assigned to the ICAD group and the remaining 174 to the non-ICAD group. The final successful reperfusion and favorable outcome rates showed no statistically significant differences in two groups. Mortality within 90 days was relatively lower in the ICAD group (6.90% vs. 17.24%; p = 0.054).ConclusionThe Neurohawk retriever is non-inferior to the Solitaire FR in the mechanical thrombectomy of large vessel occlusion-acute ischemic stroke (LVO-AIS). The sub-analysis suggested that endovascular treatment including thrombectomy with the retriever and essential rescue angioplasty is effective and safe in AIS patients with intracranial atherosclerotic disease-larger vessel occlusion (ICAD-LVO).Clinical trial registrationhttps://clinicaltrials.gov/ct2/show/NCT04995757, number: NCT04995757
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De novo variants in congenital diaphragmatic hernia identify MYRF as a new syndrome and reveal genetic overlaps with other developmental disorders
Congenital diaphragmatic hernia (CDH) is a severe birth defect that is often accompanied by other congenital anomalies. Previous exome sequencing studies for CDH have supported a role of de novo damaging variants but did not identify any recurrently mutated genes. To investigate further the genetics of CDH, we analyzed de novo coding variants in 362 proband-parent trios including 271 new trios reported in this study. We identified four unrelated individuals with damaging de novo variants in MYRF (P = 5.3x10-8), including one likely gene-disrupting (LGD) and three deleterious missense (D-mis) variants. Eight additional individuals with de novo LGD or missense variants were identified from our other genetic studies or from the literature. Common phenotypes of MYRF de novo variant carriers include CDH, congenital heart disease and genitourinary abnormalities, suggesting that it represents a novel syndrome. MYRF is a membrane associated transcriptional factor highly expressed in developing diaphragm and is depleted of LGD variants in the general population. All de novo missense variants aggregated in two functional protein domains. Analyzing the transcriptome of patient-derived diaphragm fibroblast cells suggest that disease associated variants abolish the transcription factor activity. Furthermore, we showed that the remaining genes with damaging variants in CDH significantly overlap with genes implicated in other developmental disorders. Gene expression patterns and patient phenotypes support pleiotropic effects of damaging variants in these genes on CDH and other developmental disorders. Finally, functional enrichment analysis implicates the disruption of regulation of gene expression, kinase activities, intra-cellular signaling, and cytoskeleton organization as pathogenic mechanisms in CDH
Visual object tracking: in the simultaneous presence of scale variation and occlusion
Visual object tracking is a challenging task when the object appearance changes caused by the scale variation and the occlusion. In this paper, an object tracking algorithm is proposed which is capable of dealing with the case that the scale variation and the occlusion occur simultaneously. A kernelized correlation filter (KCF) is first learned to obtain the correlation response, whose maximum value denotes the optimal object location. In order to represent the sample better, the convolutional features are extracted from a pre-trained convolutional neural networks (CNNs). Then, the strategy of scale adaption is used to estimate the object scale during the tracking process. Subsequently, a novel re-detection model is proposed by using a support vector machine (SVM) classifier to re-find the object when the occlusion occurs. The comparison experiments are implemented on the object tracking benchmark (OTB) and the results demonstrate that the proposed tracking algorithm outperforms other state-of-the-art ones in terms of precision and success rate
Investigations of the OH
OH− absorption bands of both congruent and near-stoichiometric LiNbO3:Hf crystals were investigated. The abrupt blueshift of OH− absorption bands was found between the doping levels of 2 and 2.5 mol% in the congruent crystals, which confirms the exact optical-damage threshold for Hf doping. The absorption difference of OH− bands between the congruent and near-stoichiometric crystals shows that after Li incorporation H+ ions no longer prefer the sites of 3500 cm−1. Moreover, with the increase of Hf doping in the near-stoichiometric crystals, H+ ions were found to gradually transfer to the sites of 3489 cm−1. These results are explained by the breakdown of the association of HfNb− and H+ ions and the subsequent redistribution of H+ ions around HfLi3+ ions in VLi−-deficient lattice. Additionally, the link between the intrinsic defects and how they influence the optical-damage threshold upon adding Hf was discussed in detail
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