Conditional DETR for Fast Training Convergence

The recently-developed DETR approach applies the transformer encoder and decoder architecture to object detection and achieves promising performance. In this paper, we handle the critical issue, slow training convergence, and present a conditional cross-attention mechanism for fast DETR training. Our approach is motivated by that the cross-attention in DETR relies highly on the content embeddings for localizing the four extremities and predicting the box, which increases the need for high-quality content embeddings and thus the training difficulty. Our approach, named conditional DETR, learns a conditional spatial query from the decoder embedding for decoder multi-head cross-attention. The benefit is that through the conditional spatial query, each cross-attention head is able to attend to a band containing a distinct region, e.g., one object extremity or a region inside the object box. This narrows down the spatial range for localizing the distinct regions for object classification and box regression, thus relaxing the dependence on the content embeddings and easing the training. Empirical results show that conditional DETR converges 6.7x faster for the backbones R50 and R101 and 10x faster for stronger backbones DC5-R50 and DC5-R101. Code is available at https://github.com/Atten4Vis/ConditionalDETR.Comment: Accepted by ICCV 2021. The first two authors share first authorship, and the order was determined by rolling dic

A new chemically amplified electrochemical system for DNA detection in solution

A newly developed chemically amplified electrochemical detection system was applied to the quantitation of DNA in solution. The system employed Ru(bpy)2dppz (bpy = 2,2′-bipyridine, dppz = dipyrido[3,2-a :2′,3′-c]phenazine), a high-affinity DNA intercalator, as the electrochemical indicator, oxalate as the sacrificial electron donor to chemically amplify the electrochemical signal, and tin-doped indium oxide as the working electrode to suppress background current. Intercalation of Ru(bpy)2dppz into calf thymus DNA in solution led to a reduction in the oxalate-amplified electrochemical current as compared to a DNA-free solution. The degree of reduction was a function of the concentration of DNA, thus forming the basis for DNA detection. To illustrate the advantages of the new system, a direct comparison was made between amplified (with oxalate) and non-amplified (without oxalate) DNA detection. In the presence of 100 mM oxalate, anodic current of Ru(bpy)2dppz was amplified by more than 60 folds, resulting in substantial improvement in signal-to-background ratio. Furthermore, as the DNA concentration was increased, the amplified current decayed much faster than the non-amplified signal, giving rise to higher detection sensitivity. The steeper decay was attributed to slower redox reaction between DNA-intercalated Ru(bpy)2dppz and oxalate, as the negatively charged phosphate groups on DNA repelled the anions. Effect of ionic strength was investigated to provide support for the interpretation. As expected, the decay of the amplified response with increasing concentration of DNA became less steep when more NaCl was added into the solution. The opposite effect was observed when tri-propylamine, a cationic electron donor, was used instead of oxalate. With an optimized concentration of 30 mM oxalate and 5 μM Ru(bpy)2dppz, calf thymus DNA of as low as 1 pM was detected in solution, which was close to the detection limit of some fluorescence measurements. Keywords: Electrochemical detection, Chemical amplification, DNA, Intercalation, Ru(bpy)2dpp

Forest plots of impact of MMP-2 expression on survival.

<p>HRs with corresponding 95% CIs of MMP-2 expression on (a) OS and (b) DFS/RFS/DDFS.</p

Funnel plots and sensitivity analyses of the meta-analysis.

<p>Funnel plots of the meta-analysis assessing (a) MMP-2 expression and OS (b) MMP-2 expression and RFS/DFS. Sensitivity analyses of the meta-analysis assessing (c) MMP-2 expression and OS (d) MMP-2 expression and DFS/RFS/DDFS.</p

The Impact of Matrix Metalloproteinase 2 on Prognosis and Clinicopathology of Breast Cancer Patients: A Systematic Meta-Analysis

<div><p>Backgrounds</p><p>Matrix metalloproteinase 2 (MMP-2) plays a crucial role in the progression of breast cancer (BC). The prognostic role of MMP-2 expression in BC patients has been widely reported, but the results were inconsistent. Thus, a meta-analysis was conducted to gain a better insight into the impact of MMP-2 expression on survival and clinicopathological features of BC patients.</p><p>Methods</p><p>Identical search strategies were used to search relevant literatures in electronic databases update to August 1, 2014. Individual hazard ratios (HRs) and odds ratios (ORs) with their 95% confidence intervals (CIs) were extracted and pooled to evaluate the strength of the association between positive MMP-2 expression and survival results and clinicopathological features of BC patients. Begg’s tests, Egger’s tests and funnel plots were used to evaluate publication bias. Heterogeneity and sensitivity analysis were also assessed. All the work was completed using STATA.</p><p>Results</p><p>Pooled HRs and 95% CIs suggested that MMP-2 expression had an unfavorable impact on both OS (HR: 1.53, 95% CI: 1.29–1.82) and DFS/RFS/DDFS (HR: 1.41, 95% CI: 1.07–1.86) in BC patients. Furthermore, MMP-2 expression was significantly associated with lymph node metastasis (positive vs negative: OR 1.91, 95% CI 1.17–3.12).</p><p>Conclusion</p><p>In conclusion, positive MMP-2 expression might be a significant predictive factor for poor prognosis in patients with BC.</p></div

Characteristics of eligible studies for survival outcomes in meta-analysis.

<p><i>NR</i> not reported, <i>POSI</i> positive, <i>T</i> tumor cells, <i>S</i> stromal cells, <i>CS</i> complex score combining intensity and percentage, <i>HR</i> HR reported in text, <i>A</i> HR available data or Kaplan—Meier curves, <i>U</i> univariate model, <i>M</i> multivariate model.</p><p>Characteristics of eligible studies for survival outcomes in meta-analysis.</p

Funnel plots of impact of MMP-2 expression on OS with Trim and Fill method.

<p>Funnel plots of impact of MMP-2 expression on OS with Trim and Fill method.</p

Characteristics of eligible studies for clinicopathological features in meta-analysis.

<p><i>NR</i> not reported, <i>T</i> Tumor cells, <i>S</i> stromal cells, <i>T/S</i> either tumor cells or stromal cells, <i>CS</i> complex score combining intensity and percentage, √ data available for calculating OR and 95%CI.</p><p>Characteristics of eligible studies for clinicopathological features in meta-analysis.</p