Impact of Image Denoising Techniques on CNN-based Liver Vessel Segmentation using Synthesis Low-dose Contrast Enhanced CT Images

Liver vessel segmentation in contrast enhanced CT (CECT) image is relevant for several clinical applications. However, the liver segmentation on noisy images obtain incorrect liver vessel segmentation which may lead to distortion in the simulation of cooling effect near the vessels during the planning. In this study, we present a framework that consists of three well-known and state-of-the-art denoising techniques, Vesssel enhancing diffusion (VED), RED-CNN, and MAP-NN and using a state-of-the-art Convolution Neural Networks (nn-Unet) to segment the liver vessels from the CECT images. The impact of denoising methods on the vessel segmentation are ablated using with multi-level simulated low-dose CECT of the liver. The experiment is carried on CECT images of the liver from two public and one private datasets. We evaluate the performance of the framework using Dice score and sensitivity criteria. Furthermore, we investigate the efficient of denoising on roughness of the surface of liver vessel segmentation. The results from our experiment suggest that denoising methods can improve the liver vessel segmentation quality in the CECT image with high low-dose noise while they degrade the liver vessel segmentation accuracy for low-noise-level CECT images

Balanced homodyne detection in second-harmonic generation microscopy

We demonstrate the association of two-photon nonlinear microscopy with balanced homodyne detection for investigating second harmonic radiation properties at nanoscale dimensions. Variation of the relative phase between second-harmonic and fundamental beams is retrieved, as a function of the absolute orientation of the nonlinear emitters. Sensitivity down to approximately 3.2 photon/s in the spatio-temporal mode of the local oscillator is obtained. This value is high enough to efficiently detect the coherent second-harmonic emission from a single KTiOPO4 crystal of sub-wavelength size.Comment: 9 pages to appear in Applied Physics Letter

Automatic 3-D Optical Detection on Orientation of Randomly Oriented Industrial Parts for Rapid Robotic Manipulation

This paper proposes a novel method employing a developed 3-D optical imaging and processing algorithm for accurate classification of an object’s surface characteristics in robot pick and place manipulation. In the method, 3-D geometry of industrial parts can be rapidly acquired by the developed one-shot imaging optical probe based on Fourier Transform Profilometry (FTP) by using digital-fringe projection at a camera’s maximum sensing speed. Following this, the acquired range image can be effectively segmented into three surface types by classifying point clouds based on the statistical distribution of the normal surface vector of each detected 3-D point, and then the scene ground is reconstructed by applying least squares fitting and classification algorithms. Also, a recursive search process incorporating the region-growing algorithm for registering homogeneous surface regions has been developed. When the detected parts are randomly overlapped on a workbench, a group of defined 3-D surface features, such as surface areas, statistical values of the surface normal distribution and geometric distances of defined features, can be uniquely recognized for detection of the part’s orientation. Experimental testing was performed to validate the feasibility of the developed method for real robotic manipulation.<br /

How does the knowledge accumulation process affect Vietnamese entrepreneurs’ success likelihood?

The nationwide economic reform in 1986 transformed Vietnam from a centrally planned economy to a socialist-oriented market economy. Entrepreneurs and entrepreneurial spirits within the populace are suggested to fuel the structural changes. Despite the importance of entrepreneurship in Vietnam’s economy, studies in Vietnam mainly pay attention to the practical aspects of entrepreneurial activities and neglect the cognitive and theoretical aspects of entrepreneurship. Thus, the current study employs the information-processing perspective of the Mindsponge Theory to explore how entrepreneurs’ knowledge accumulation can affect their perceived likelihood of business success. Bayesian analysis indicates that business-related experience positively affects entrepreneurs’ business success likelihood. Greater willingness/readiness to transform thinking, acting, and beliefs can improve the business success of entrepreneurs who study others’ failures carefully. However, for entrepreneurs who perceive learning from others’ failures as unnecessary, higher willingness/readiness to transform diminishes their chance of success. Based on these findings, we recommend Vietnamese entrepreneurs accumulate knowledge through experience, learning, and an open mind for better decision-making and innovation creation capabilities. However, the learning process should be selective

The effect of different media and temperature conditions for Salmonella bacteriophage preservation

This research aimed to determine the optimal media and temperature conditions for the long-term storage of bacteriophages. In this study, the viability of Salmonella phages in 50% glycerol, 10% sodium chloride-magnesium sulfate (SM) buffer, and 5% dimethyl sulfoxide (DMSO) media at room temperature, 4oC, -20oC, and -80oC for 12 months was determined. In 50% glycerol, at the end of the experiment, no significant difference was found between four temperature conditions on phage density, ranging from 6.20-6.23 log10 PFU/mL (P>0.05). Under 10% SM medium, phage preservation at room temperature provided the optimum density at 6.31 log10 PFU/mL. In addition, phages preserved in a 5% DMSO medium were of similar density values across all temperature treatments. Still, their availability after 12 month-storage (88.0-88.5%) was significantly lower (P<0.05) than that of 50% glycerol and 10% SM. Moreover, for phage lysis capacity, low temperatures (4oC, -20oC, and -80oC) were superior to room temperature used for preservation. Considering the density, lysis capacity, and practical convenience, storing phages at 4°C in a 50% Glycerol medium is recommended

Diterpenoids from Fokienia hodginsii.

In continuous research on the chemical constituents of the twigs and leaves of Fokienia hodginsii (Dunn) A. Henry et Thomas growing in Highland, Lam Dong province 4 diterpenoids, including 3-oxo-totarol (totarolone, 1), 3β-hydroxytotarol (2), 15-nor-labda-8(17),12E-diene-14-carboxaldehyde-19-oic acid (3) and 13-oxo-15,16-dinorlabda-8(17),11E-diene-19-oic acid (4) were isolated. Their structures were elucidated by the spectroscopic methods and comparison with reported data. This is the first report on the isolation of compounds 1, 2 and 3 from this plant. Keywords. Fokienia hodginsii; totarane; nor-labdane diterpenoid

Terpenoids from Dacrycarpus imbricatus.

The phytochemical investigation of the hexane extract from the twigs and leaves of Dacrycarpus imbricatus (Blume) de Laub led to the isolation of a rare sesquiterpene, spathulenol (1) along with three diterpenes named pimaric acid (2), trans-communic acid (3) and cis-communic acid (4). Their structures were determined by combination of spectral analysis and comparison with reported data. This is the first report on isolation of compound 1 from the Podocarpaceae family. Keywords. Dacrycarpus imbricatus, spathulenol, pimaric acid, communic acid

Génération de seconde harmonique à l'échelle nanométrique : nanocristaux de KTP, exaltation par un réseau métallique

One promising development of second-harmonic generation (SHG) microscopy is to use nanolabels that can generate a strong and coherent emission. In this theses, we propose for the first time studies of KTiOPO4 (KTP), a nonlinear material widely used in laser technology, under SHG microscopy at the single nanoparticle level. Such light source can find numerous applications, for instance as an in situ active probe for novel optical near-field microscopy, or marker for biology. Our approach is generic and can be readily applied to other nanocrystal candidates for coherent nonlinear microscopy.L'utilisation des nanolabels avec une émission forte et cohérente constitue un développement prometteur de la microscopie de génération de second harmonique (GSH). Dans ce travail de thèse, nous proposons pour la première fois les études de KTiOPO4 (KTP), un matériau non-linéaire bien connu, sous microscopie de GSH à l'échelle de nanoparticule unique. Ce nanosource de lumière peut trouver de nombreuses applications, par exemple comme sonde active de microscopie en champ proche, ou comme marqueur pour la biologie. Nottre approche est générique et peut être appliquée pour d'autre type de nanocristaux pour la microscopie cohérente