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Carotid arteries vulnerable plaques are a crucial factor in the screening of atherosclerosis by ultrasound technique. However, the plaques are contaminated by various noises such as artifact, speckle noise, and manual segmentation may be time-consuming. This paper proposes an automatic convolutional neural network (CNN) method for plaque segmentation in carotid ultrasound images using a small dataset. First, a parallel network with three independent scale decoders is utilized as our base segmentation network, pyramid dilation convolutions are used to enlarge receptive fields in the three segmentation sub-networks. Subsequently, the three decoders are merged to be rectified in channels by SENet. Thirdly, in test stage, the initially segmented plaque is refined by the max contour morphology post-processing to obtain the final plaque. Moreover, three loss function Dice loss, SSIM loss and cross-entropy loss are compared to segment plaques. Test results show that the proposed method with dice loss function yields a Dice value of 0.820, an IoU of 0.701, Acc of 0.969, and modified Hausdorff distance (MHD) of 1.43 for 30 vulnerable cases of plaques, it outperforms some of the conventional CNN-based methods on these metrics. Additionally, we apply an ablation experiment to show the validity of each proposed module. Our study provides some reference for similar researches and may be useful in actual applications for plaque segmentation of ultrasound carotid arteries., Comment: 16 pages,6 figures

Additional file 1: Figure S1 Chromosome distribution of Oleosin genes in four cotton species. Figure S2 Collinearity analyses of Oleosin genes between G. hirsutum, G. barbadense, G. arboretum, and G. raimondii. Figure S3 The prediction of transmembrane helices in SH GhOLEO proteins. nC, N-terminus inside and C-terminus outside; Nc, N-terminus outside and C-terminus inside. Figure S4 The prediction of transmembrane helices in SL GhOLEO proteins. NC, both N-terminus and C-terminus outside. Figure S5 The prediction of transmembrane helices in U GhOLEO proteins. nC, N-terminus inside and C-terminus outside; Nc, N-terminus outside and C-terminus inside; NC, both N-terminus and C-terminus outside.

Functional graphene oxide (FGO) with photosensitivity was incorporated into the photosensitive polyimide (PSPI) matrix via solution blending, to prepare the photocrosslinkable nano-composite films. The crosslinked composite films were obtained through UV irradiation. FGO was well dispersed in PSPI matrix and effectively covalently bonded to PSPI main chains through photo-chemical reaction. Due to the confine of electronic polarization caused by the crosslinked structure, the dielectric constant (k) and dielectric loss tangent (tan δ) of the crosslinked PSPI/FGO films decreased effectively, which could be tuned by varying both the UV irradiation time and FGO loading. Among all the composite films, the film with 0.5 wt% FGO content exposed under UV light for 900 s had the lowest k (2.58) and tan δ (0.026) values at 10 MHz. These findings suggest that PSPI/FGO composite films are promising application in the field of photoresist with low dielectric constant.

In this study, a maleimido-substituted aromatic s-triazine (TMT) was synthesized successfully via the nucleophilic substitution reaction between cyanuric chloride and N-(4-hydroxyphenyl) maleimide (HPM) formed from paraaminophenol and maleic anhydride; and its structure was characterized by flourier transform infrared spectroscope (FT-IR), 1 H and 13 C nuclear magnetic resonance (NMR), and elemental analysis (EA). The studied flame-retarded epoxy resins were obtained via thermal curing reactions among 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) modified epoxy prepolymer (DOPOER), 4,4′-diaminodiphenyl ethane (DDM) and TMT. Cure kinetics, flame-retardant, thermal and mechanical properties of the cured epoxy resins were characterized by differential scanning calorimeter (DSC), thermogravimeric analysis (TGA), limited oxygen index (LOI) measurement, UL 94 vertical burning test and mechanical test. The results indicate that TMT can promote the curing reaction of epoxy resins and decrease its apparent activation energy ( E a ). Introduction of TMT can greatly improve flame-retardant, thermal and mechanical properties of the cured epoxy resins. Compared with the DOPOER/DDM system without TMT, LOI value of the cured epoxy resin can increase from 36.4% to 51.8%, and all samples can pass UL 94 V-0 rate when TMT content ranges from 1.98 wt% to 7.44 wt%. Its initial degradation temperature and glass transition temperature ( T g ) can increase maximally by 37.6 °C and 12.6 °C, respectively when TMT content is 3.88 wt%.

As a new graphene derivative, graphene fluoroxide (GFO) has not been fully studied because of its complex preparation process. In this paper, two simple methods, a modified Hummers' method and an improved method, were adopted to oxidize unsaturated commercial graphite fluoride (GIF) to prepare graphite fluoroxide (GIFO), the precursor of GFO. GFO was finally obtained via liquid-phase ultrasonic exfoliation of GIFO in organic solvents. Multiple spectroscopic techniques were used to characterize GIFO and GFO. The test results indicate that both of the two methods can covalently bond oxygen functional groups to graphene fluoride (GF) sheets successfully, but the modified Hummers' method gives higher yield and oxidizability. The structure of the GFO sheet is confirmed as few-layer by its atomic force microscopy results and transmission electron microscopy images. UV-vis and fluorescence emission measurements suggest that introducing oxygen groups into GF sheets can change their optoelectronic properties. Based on this, GFO with tunable optoelectronic properties might be facilely obtained in large batches through oxidization and liquid-phase exfoliation of unsaturated GIF with different fluorine coverage.