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Tumor Cell Identification in Ki-67 Images on Deep Learning
Get PDFThe proportion of cells staining for the nuclear antigen Ki-67 is an important predictive indicator for assessment of tumor cell proliferation and growth in routine pathological investigation. Instead of traditional scoring methods based on the experience of a trained laboratory scientist, deep learning approach can be automatically used to analyze the expression of Ki-67 as well. Deep learning based on convolutional neural networks (CNN) for image classification and single shot multibox detector (SSD) for object detection are used to investigate the expression of Ki-67 for assessment of biopsies from patients with breast cancer in this study. The results focus on estimating the probability heatmap of tumor cells using CNN with accuracy of 98% and detecting the tumor cells using SSD with accuracy of 90%. This deep learning framework will provide an objective basis for the malignant degree of breast tumors and be beneficial to the pathologists for fast and efficiently Ki-67 scoring
Comparative Study on Diagonal Strut Model of Infill Wall
Get PDFThe equivalent diagonal strut models of infill wall mainly include the single strut model and multi-strut model. Firstly, several equivalent strut models and their characteristics are introduced in this paper. Then, model analysis and pushover analysis are carried out on infilled frame models with the aid of the software SAP2000. Two typical single strut models and a typical three-strut model are used to simulate the panel of the frames respectively. It is indicated that the period reduction factor of the frame with a three-strut model is close to the value recommended by the current code. The infill wall has great influence on the overall stiffness, bearing capacity and weak position of the structure. The stiffness and the bearing capacity of the infilled frame increase with the increase of the number of the infill walls. The unfilled story is the weak position of the infilled frame, and when the unfilled story at the bottom of the infilled frame, the seismic response of the upper infill layer decreases with the increasing of the number of unfilled story
Biobased Vanillic Acid and Ricinoleic Acid: Building Blocks for Fully Renewable Copolyesters
No full textNew fully biobased polyether/esters have been synthesized by a one-pot polymerization reaction of ricinoleic acid (RA), vanillic acid (VA) and ethylene carbonate (EC). In particular, EC selectively reacts with the phenolic group of VA to obtain in-situ 4-(2-hydroxyethoxy)-3-methoxybenzoate (EV), suitable for subsequent copolymerization with RA. The procedure was carried out in a single step, without any solvent. Chemical structure and thermal properties of the new materials were studied in order to explore relationships between composition and final performances. The combination of EV, bearing a rigid aromatic structure, with RA, characterized by high flexibility and potential biocidal activity, allows the production of a novel class of fully biobased aliphatic-aromatic polymers presenting tuneable thermal properties and suitable for a range of applications, for example, in active packaging and biomedical fields
Valorization of Kraft Lignin as Thickener in Castor Oil for Lubricant Applications
Get PDFIt is known that large amounts of residual lignin are generated in the pulp and paper industry. A new alternative for Kraft lignin valorization, which consists of first a chemical modification using a diisocyanate and then the efficient dispersion in castor oil to achieve stable gel-like systems, is proposed in this work. Rheological properties and microstructure of these materials were determined by means of small amplitude oscillatory shear tests and viscous flow measurements and atomic force microscopy observations, respectively. Moreover, both standardized penetration tests and tribological assays, usually performed in the lubricant industry, were carried out to evaluate the performance characteristics as lubricating greases. Linear viscoelasticity functions are affected by the lignin/diisocyanate ratio and thickener concentration. The thermorheological response evidenced a softening temperature of around 105 °C. The microstructure of these gel-like dispersions is composed of interconnected thin fibers, homogeneously distributed in castor oil. Moreover, the NCO-functionalized lignin gel-like dispersions studied show lower friction coefficients than traditional lubricating greases
Antioxidant Migration Studies in Chitosan Films Incorporated with Plant Extracts
Get PDFThe aim of this work was to develop an active biopolymer based on chitosan by incorporating natural antioxidants. Five essential oils (ginger, rosemary, sage, tea tree and thyme) and six hydro-alcoholic extracts (from ginger, green and black tea, kenaf leaves, rosemary and sage plants) were tested. Migration assays were carried out to evaluate the films' activity, and total phenolic content and antioxidant activity were monitored in the simulant during storage. Interaction between natural compounds and polymeric matrix was evaluated by FTIR spectroscopy. The diffusion of the phenolic compounds was not detected in the films incorporated with hydro-alcoholic extracts (HAEs), indicating their entrapment in the chitosan. Migration was observed in the films with essential oils (EOs), and biobased films incorporated with ginger, sage or rosemary essential oils, presented the highest diffusion and antioxidant activity in the simulant, highlighting their functionality and potential to be used as food active packaging material
Enzymatic Degradation of Poly(butylenesuccinate)/ Thermoplastic Starch Blend
No full textThe degradation of thermoplastic starch blend in the presence of commercial α-amylase and unpurified amylase of microbial origin was investigated. The blends consisting of thermoplastic starch and poly(butylene succinate) have potential use in packaging applications thus, it is essential to establish susceptibility to degradation. Molar mass loss, gravimetric weight loss, and molecular structure were evaluated. The changes in the surface were observed with scanning electron microscopy. It was confirmed that there was a significant difference in gravimetric weight loss between the blends degraded in two different solutions. Unpurified enzymes of microbial origin, produced by Rhizopus oryzae cultures decomposed analyzed materials more efficiently than purified commercial ones. Moreover, it was proved that in applied conditions, the molar mass of PBS fraction did not change significantly
Preparation and Characterization of Alkyd Resins Based on Citrullus colocynthis Seed Oil
No full textIn this study, different samples of alkyd resins based on Citrullus colocynthis seed oil (CCSO)—which has a high content of linoleic acid—were prepared as a renewable raw material. Short (I), medium (II), and long (III) alkyd resins were synthesized using oil, glycerol, and phthalic anhydride (PA) in different proportions. Prunus mahaleb seed oil (PMSO), which contains conjugated linolenic acid, was blended with CCSO in different proportions to examine the effect of PMSO on the film properties of alkyd resins (IV and V). All synthesized resins were characterized by FTIR and 1H NMR spectroscopic analysis. These resins were also cured by an epoxy resin and their film properties (pencil hardness, adhesion, gloss, and chemical resistance) were determined. Analysis of these alkyds reveals that CCSO can be used as a new potential raw material for coating applications
The Influence of the Imperfectness of Contact Conditions on the Critical Velocity of the Moving Load Acting in the Interior of the Cylinder Surrounded with Elastic Medium
Get PDFThe dynamics of the moving-with-constant-velocity internal pressure acting on the inner surface of the hollow circular cylinder surrounded by an infinite elastic medium is studied within the scope of the piecewise homogeneous body model by employing the exact field equations of the linear theory of elastodynamics. It is assumed that the internal pressure is point-located with respect to the cylinder axis and is axisymmetric in the circumferential direction. Moreover, it is assumed that shear-spring type imperfect contact conditions on the interface between the cylinder and surrounding elastic medium are satisfied. The focus is on the influence of the mentioned imperfectness on the critical velocity of the moving load and this is the main contribution and difference of the present paper the related other ones. The other difference of the present work from the related other ones is the study of the response of the interface stresses to the load moving velocity, distribution of these stresses with respect to the axial coordinates and to the time. At the same time, the present work contains detail analyses of the influence of problem parameters such as the ratio of modulus of elasticity, the ratio of the cylinder thickness to the cylinder radius, and the shear-spring type parameter which characterizes the degree of the contact imperfection on the values of the critical velocity and stress distribution. Corresponding numerical results are presented and discussed. In particular, it is established that the values of the critical velocity of the moving pressure decrease with the external radius of the cylinder under constant thickness of that
A Nonlinear Magneto-Mechanical Coupled Constitutive Model for the Magnetostrictive Material Galfenol
Get PDFIn order to predict the performance of magnetostrictive smart material and push its applications in engineering, it is necessary to build the constitutive relations for the magnetostrictive material Galfenol. For Galfenol rods under the action of the pre-stress and magnetic field along the axial direction, the one-dimensional nonlinear magneto-mechanical coupling constitutive model is proposed based on the elastic Gibbs free energy, where the Taylor expansion of the elastic Gibbs free energy is made to obtain the polynomial forms. And then the constitutive relations are derived by replacing the polynomial forms with the proper transcendental functions based on the microscopic magneto-mechanical coupling mechanism. From the perspective of microscopic mechanism, the nonlinear strain related to magnetic domain rotation results in magnetostrictive strain changing with the pre-stress among the elastic strains induced by the pre-stress. By comparison, the predicted stress-strain, magnetostrictive strain, magnetic induction and magnetization curves agreed well with experimental results under the different pre-stresses. The proposed model can describe not only the influences of pre-stress on magnetostrictive strain and magnetization curves, but also nonlinear magneto-mechanical coupling effect of magnetostrictive material systematically, such as the Young’s modulus varying with stress and magnetic field. In the proposed constitutive model, the key material constants are not chosen to obtain a good fit with the experimental data, but are measured directly by experiments, such as the saturation magnetization, saturation magnetostrictive coefficient, saturation Young’s modulus, linear magnetic susceptibility and so on. In addition, the forms of the new constitutive relations are simpler than the existing constitutive models. Therefore, this model could be applied conveniently in the engineering applications
Investigation of the Short-Time Photodissociation Dynamics of Furfural in S<sub>2</sub> State by Resonance Raman and Quantum Chemistry Calculations
Get PDFRaman (resonance Raman, FT-Raman), IR and UV-visible spectroscopy and quantum chemistry calculations were used to investigate the photodissociation dynamics of furfural in S2 state. The resonance Raman(RR) spectra indicate that the photorelaxation dynamics for the S0→S2 excited state is predominantly along nine motions: C=O stretch ν5 (1667 cm-1), ring C=C antisymmetric stretch ν6 (1570 cm-1), ring C=C symmetric stretch ν7 (1472 cm-1), C2-O6-C5 symmetric stretch/C1-H8 rock in plane ν8 (1389 cm-1), C3-C4 stretch/ C1-H8 rock in plane ν9 (1370 cm-1), C5-O6 stretch in plane ν12 (1154 cm-1), ring breath ν13 (1077 cm-1), C3-C4 stretch ν14 (1020 cm-1), C3-C2-O6 symmetric stretch ν16 (928 cm-1 ). Stable structures of S0, S1, S2, T1 and T2 states with Cs point group were optimized at CASSCF method in Franck-Condon region there are S2/S1 conical intersection was found by state average method and RR spectra