Automatic breast tumor detection in ABVS images based on convolutional neural network and superpixel patterns

Breast cancer is one of the most common female malignancies, as well as the second leading cause of mortality for women. Early detection and treatment can dramatically decrease the mortality rate. Recently, automated breast volume scanner (ABVS) has become one of the most frequently used diagnose methods for breast tumor screening because of its operator-independent and reproducible advantages. However, it is a challenging job to obtain the tumors’ accurate locations and shapes by reviewing hundreds of ABVS slices. In this paper, a novel computer-aided detection (CADe) system is developed to reduce clinicians’ reading time and improve the efficiency. The CADe system mainly contains three parts: tumor candidate acquisition, false-positive reduction and tumor segmentation. Firstly, a local phase-based approach is built to obtain breast tumor candidates for further recognition. Subsequently, a convolutional neural network (CNN) is applied to reduce false positives (FPs). The introduction of CNN can help to avoid complicated feature extraction as well as elevate the accuracy and efficiency. Finally, superpixel-based segmentation is used to outline the breast tumor. Here, superpixel-based local binary pattern (SLBP) is proposed to assist the segmentation, which improves the performance. The methods were evaluated on a clinical ABVS dataset whose abnormal cases were manually labeled by an experienced radiologist. The experiment results were mainly composed of two parts. At the FP reduction stage, the proposed CNN achieved 100% and 78.12% sensitivity with FPs/case of 2.16 and 0. At the segmentation stage, our SLBP obtained 82.34% true positive, 15.79% false positive and 83.59% Dice similarity. In summary, the proposed CADe system demonstrated promising potential to detect and outline breast tumors in ABVS images.

     

Strength and chemical resistance of mortars containing brick manufacturing clays subjected to different treatments

This paper presents the results of an investigation of the properties of mortar in which a calcined clay was employed as a pozzolan. Mortars were prepared using either heat treated clay or ground waste clay bricks (from the same clay subjected to 1000 °C calcining) as a pozzolanic partial replacement for cement at replacement levels of 10%, 20% and 30%. The compressive strengths of the mortars were monitored up to 90 days and the resistance to sodium sulphate solution and synthetic seawater was monitored up to 300 days. The specimens were also monitored for weight changes. Partially replacing cement by ground brick or heat-treated brick clay gives early strengths that are lower than that of the control. At 90 days, however, the strengths are the same as or are greater than that of the control. Heat-treated clay is effective in reducing expansion during exposure of the mortar to sulphate solution and synthetic seawater. The rapidly cooled clay gives better performance, in terms of strength development and resistance to harmful solutions, than the slow cooled clay.     

2,3,4- or 2,3,5-trisubstituted furans: catalyst-controlled highly regioselective ring-opening cycloisomerization reaction of cyclopropenyl ketones

2,3,4- or 2,3,5-trisubstituted furans were highly regioselectively formed from the cycloisomerization reaction of the same starting cyclopropenes 1 via the subtle choice of the transition metal halides. Under the catalysis of 5 mol % PdCl2(CH3CN)2, 2,3,5-trisubstituted furans 2 were given in 50-88% yields with 95-99% regioselectivities, while 2,3,4-trisubstituted furans 3 were formed in 78-96% yields with 99% regioselectivities under the catalysis of 5 mol % CuI.     

1,4,5,8-四氮杂氢化萘（2,3,-6,7）并双呋咱衍生物的合成

由1，4，5，8—四氮杂氢化萘(2，3，-6，7)并双呋咱经羟甲基化、酰化、硝化和叠氮化等反应合成出一系列热稳定的呋咱含能衍生物，并以^1HNMR、IR、MS、元素分析鉴定了其结构。     

煤矸石作水泥混合材的活化方法研究

论述了煤矸石用作水泥混合材时如何激发其活性的若干方法 ,介绍了通常所用的热激活、物理激活和化学激活煤矸石的机理。实验显示了各种激活方法的效果 ,近而讨论了提高煤矸石活性时应注意的问题     

Theoretical and experimental investigation of flow and heat transfer in an internally-heated naturally-ventilated space

This paper presents the findings of a theoretical and experimental investigation of the thermodynamics of an internally heated control volume, ventilated by natural convection. A simple bench-type experiment has been used to determine the temperature history of the air, in support of a global calculation by numerical methods. Good agreement has been achieved between the experimental results and the mathematical prediction, which has wide ranging applications in practical situations.     

On the involvement of radical oxygen species O− in catalytic oxidation of benzene to phenol by nitrous oxide

Catalytic oxidation of benzene to phenol by nitrous oxide over Fe-MFI zeolites was studied in relation to the active oxygen species taking part in the oxidation. A linear dependence of the reaction rate on the concentration of independently identified active sites generating O⁻ radicals (α sites) was obtained within a broad range of values. The dependence is interpreted as convincing evidence of the O⁻ involvement in the catalytic (not only stoichiometric) oxidation of benzene to phenol. This conclusion is of particular importance in connection with a long discussion in the literature on a possible role of O⁻ radicals in selective oxidation catalysis over V and Mo oxides. Reliable evidence of the catalytic role of O⁻ obtained with zeolites may renew general interest in the once-suggested but not recognized role of radical oxygen in oxidation over widely used metal oxide catalysts.     

新化合物ZJ2242对几种鳞翅目害虫的杀虫活性

室内生测结果表明,ZJ2242对粘虫、小菜蛾和斜纹夜蛾等鳞翅目害虫表现出良好的杀虫活性,综合毒力LC50分别为2.08、59.89和16.84mg/L。毒作用方式测定表明,ZJ2242对粘虫胃毒作用明显(胃毒毒力LC50为5.03mg/L),而触杀作用很低。田间试验表明,ZJ2242对小菜蛾、斜纹夜蛾具有较好的防治作用,100～200mg/L处理7d的防效均在80%以上。     

Polyallene-based graft copolymer via 6-methyl-1,2-heptadien-4-ol and methyl methacrylate

A series of well-defined graft copolymers with a polyallene-based backbone and poly(methyl methacrylate) side chains were synthesized by the combination of living coordination polymerization of 6-methyl-1,2-heptadien-4-ol and atom transfer radical polymerization of methyl methacrylate. We first prepared poly(alcohol) with polyallene repeating units via 6-methyl-1,2-heptadien-4-ol by living coordination polymerization initiated by [(η³-allyl)NiOCOCF₃]₂, followed by transforming the pendant hydroxyl groups into halogen-containing ATRP initiation groups. Next, grafting-from route was used for the synthesis of the well-defined graft copolymer with excellent solubility: poly(methyl methacrylate) was grafted to the backbone via ATRP of methyl methacrylate. This kind of graft copolymer is the first example of graft copolymer via allene derivative and methacrylic monomer.