23 research outputs found
Multi-Scale and Multi-Branch Convolutional Neural Network for Retinal Image Segmentation
The accurate segmentation of retinal images is a basic step in screening for retinopathy and glaucoma. Most existing retinal image segmentation methods have insufficient feature information extraction. They are susceptible to the impact of the lesion area and poor image quality, resulting in the poor recovery of contextual information. This also causes the segmentation results of the model to be noisy and low in accuracy. Therefore, this paper proposes a multi-scale and multi-branch convolutional neural network model (multi-scale and multi-branch network (MSMB-Net)) for retinal image segmentation. The model uses atrous convolution with different expansion rates and skip connections to reduce the loss of feature information. Receiving domains of different sizes captures global context information. The model fully integrates shallow and deep semantic information and retains rich spatial information. The network embeds an improved attention mechanism to obtain more detailed information, which can improve the accuracy of segmentation. Finally, the method of this paper was validated on the fundus vascular datasets, DRIVE, STARE and CHASE datasets, with accuracies/F1 of 0.9708/0.8320, 0.9753/0.8469 and 0.9767/0.8190, respectively. The effectiveness of the method in this paper was further validated on the optic disc visual cup DRISHTI-GS1 dataset with an accuracy/F1 of 0.9985/0.9770. Experimental results show that, compared with existing retinal image segmentation methods, our proposed method has good segmentation performance in all four benchmark tests
Polysiloxane-Based Side Chain Liquid Crystal Polymers: From Synthesis to Structure–Phase Transition Behavior Relationships
Organosilicon polymer materials play an important role in certain applications due to characteristics of much lower glass transition temperatures (Tg), viscosities, surface energy, as well as good mechanical, thermal stabilities, and insulation performance stemming from the higher bond energy and the larger bond angles of the adjacent silicon-oxygen bond. This critical review highlights developments in the synthesis, structure, and phase transition behaviors of polysiloxane-based side chain liquid crystal polymers (PSCLCPs) of linear and cyclic polysiloxanes containing homopolymers and copolymers. Detailed synthetic strategies are elaborated, and the relationship between molecular structures and liquid crystalline phase transition behaviors is systematically discussed, providing theoretical guidance on the molecular design of the materials
Angular Photochromic LC Composite Film for an Anti-Counterfeiting Label
In the harsh application environment, improving the mechanical properties of liquid crystal materials is a fundamental and important problem in the design of anti-counterfeit materials. In this paper, by a stepwise polymerization of first, photo-polymerization and subsequently thermal-polymerization, a coexistent polymer dispersed network was first constructed in cholesteric liquid crystal materials containing a photo-polymerizable system of urethane acrylate and a thermo-polymerizable system of isocyanate. Results revealed that the coexistent polymer dispersed network exhibited largely enhanced mechanical performance, and the networks obtained by different methods had different contributions to the enhancement of the peel strength and toughness of the composite films. Then an angular photochromic anti-fake label based on a coexistent polymer dispersed network with enhanced mechanical and apparent angular discoloration characteristics, suitable for practical applications, was successfully achieved
Differentiability of a class of semi-linear hyperbolic systems with respect to a parameter
Distinct Bacterial Communities Associated with Massive and Branching Scleractinian Corals and Potential Linkages to Coral Susceptibility to Thermal or Cold Stress
Effects of huoxin formula on the arterial functions of patients with coronary heart disease
Context: Huoxin formula is a Traditional Chinese Medicine for coronary heart disease (CHD) treatment. Objective: To explore the therapeutic mechanism of the Huoxin formula on arterial functions in CHD patients. Materials and methods: Fifty-eight CHD patients receiving cardiovascular drugs including β-receptor blocker, statins, and antiplatelet medications or others were randomized into intervention [additionally 13.5 g Huoxin formula granules dissolved in 150 mL warm water per time, twice a day (n = 30)] and control [only cardiovascular drugs (n = 28)] groups. Serum biomarkers (hs-CRP, IL-18, IL-17, TNF-α, MMP-9), and cardiovascular indicators of the common and internal carotid arteries (ICAs) were monitored before and after the treatments. Results: After 3 months of treatment, the increases of intima-media thicknesses (IMT) of the left and right common carotid arteries (CCAs) as well as of the left and right ICAs and the increases of the left and right cardio-ankle vascular index were all significantly (all p < 0.001) less in the intervention than in control group (all p < 0.001). Serum concentrations reductions of hs-CRP, IL-18, IL-17 and MMP9 (all p < 0.001) levels were higher in the intervention compared to the control group, which correlated with the changes of left ICA (hs-CRP: r = 0.581, p = 0.009; IL-18: r = 0.594, p = 0.007; IL-17: r = 0.575, p = 0.006). Discussion and conclusion: Since the Huoxin formula improved arterial functions and reduced inflammatory factor activities in CHD patients, a large-scale clinical trial is warranted
Factors and aspects affecting quality of a pedagogical-psychological practice
The presented dissertation paper deals with the pre-graduate preparation of teachers, specially its integral part, pedagogical-psychological experience ("experience"). The aim of this paper is comparative study focused on analysing and comparing the conception and implementation of the current conditions of this experience. Comparison was performed between two faculties of education - Faculty of Education at Charles University in Prague and the Faculty of Education at Comenius University in Bratislava. The main research methods were comparative analysis of content, questionnaires and structured interviews. In the research part of the paper, we are trying to define issues that have positive or negative influence: motivation of students to choice of their major of study, their subjective perception of their preparedness for this kind of experience, their assessment of progress of pedagogical experience and its benefits for their future profession. We were provided with other indications by headmasters of schools where this subject was already implemented, by teachers who dedicated themselves to students and by university teachers who lead this subject. The main benefit of this paper is in comparison of both conceptions along with recommendation of the optimal form of practice that could be utilized..
Observations of short period seismic scattered waves by small seismic arrays
The most recent observations of well correlated seismic phases in the high frequency coda of local earthquakes recorded throughout the world are reported. In particular the main results, obtained on two active volcanoes, Teide and Deception, using small array are described. The ZLC (Zero Lag Cross-correlation) method and polarization analysis have been applied to the data in order to distinguish the main phases in the recorded seismograms and their azimuths and apparent velocities. The results obtained at the Teide volcano demonstrate that the uncorrelated part of the seismograms may be produced by multiple scattering from randomly distributed heterogeneity, while the well correlated part, showing SH type polarization or the possible presence of Rayleigh surface waves, may be generated by single scattering by strong scatterers. At the Deception Volcano strong scattering, strongly focused in a precise direction, is deduced from the data. In that case, all the coda radiation is composed of surface waves