113 research outputs found

    An Image Filter Based on Shearlet Transformation and Particle Swarm Optimization Algorithm

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    Digital image is always polluted by noise and made data postprocessing difficult. To remove noise and preserve detail of image as much as possible, this paper proposed image filter algorithm which combined the merits of Shearlet transformation and particle swarm optimization (PSO) algorithm. Firstly, we use classical Shearlet transform to decompose noised image into many subwavelets under multiscale and multiorientation. Secondly, we gave weighted factor to those subwavelets obtained. Then, using classical Shearlet inverse transform, we obtained a composite image which is composed of those weighted subwavelets. After that, we designed fast and rough evaluation method to evaluate noise level of the new image; by using this method as fitness, we adopted PSO to find the optimal weighted factor we added; after lots of iterations, by the optimal factors and Shearlet inverse transform, we got the best denoised image. Experimental results have shown that proposed algorithm eliminates noise effectively and yields good peak signal noise ratio (PSNR)

    Synthesis and Mechanism of Tetracalcium Phosphate from Nanocrystalline Precursor

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    Tetracalcium phosphate (TTCP, Ca4(PO4)2O) was prepared by the calcination of coprecipitated mixture of nanoscale hydroxyapatite (HA, Ca10(PO4)6(OH)2) and calcium carbonate crystal (CaCO3), followed by cooling in the air or furnace. The effect of calcination temperature on crystal structure and phase composition of the coprecipitation mixture was characterized by transmission electron microscope (TEM), thermal analysis-thermogravimetry (DTA-TG), X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FT-IR), and Raman spectroscopy (RS). The obtained results indicated that the synthesized mixture consisted of nanoscale HA and CaCO3 with uniform distribution throughout the composite. TTCP was observed in the air quenching samples when the calcination temperature was above 1185°C. With the increase of the calcination temperature, the amount of the intermediate products in the air quenching samples decreased and cannot be detected when calcination temperature reached 1450°C. Unexpectedly, the mixture of HA and calcium oxide was observed in the furnace cooling samples. Clearly, the calcination temperature and cooling methods are critical for the synthesis of high-purity TTCP. The results indicate that the nanosize of precursors can decrease the calcination temperature, and TTCP can be calcinated by low temperature

    Relation of Leptin, Ghrelin and Inflammatory Cytokines with Body Mass Index in Pulmonary Tuberculosis Patients with and without Type 2 Diabetes Mellitus

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    Background: Pulmonary tuberculosis (TB) patients often suffer from anorexia and poor nutrition, causing weight loss. The peptide hormones leptin and its counterpart ghrelin, acting in the regulation of food intake and fat utilization, play an important role in nutritional balance. This study aimed to investigate the association of blood concentrations of leptin, ghrelin and inflammatory cytokines with body mass index (BMI) in TB patients with and without type 2 diabetes mellitus (T2DM). Methods: BMI, biochemical parameters and plasma levels of leptin, ghrelin and inflammatory cytokines were measured before the start of treatment in 27 incident TB patients with T2DM, 21 TB patients and 23 healthy subjects enrolled in this study. Results: The levels of leptin were significantly higher in TB patients (35.2 +/- 19.1 ng/ml) than TB+T2DM (12.6 +/- 6.1 ng/ml) and control (16.1 +/- 11.1 ng/ml) groups. The level of ghrelin was significantly lower in TB (119.9 +/- 46.1 pg/ml) and non-significantly lower in TB+T2DM (127.7 +/- 38.6 pg/ml) groups than control (191.6 +/- 86.5 pg/ml) group. The levels of TNF-alpha were higher, while IFN-gamma and IL-6 levels were lower in patients than in the control group. Leptin showed a negative correlation with BMI in TB (r=-0.622, p0.05) groups, but negative correlation with BMI in the control (r=-0.693,

    Enhancing Higher Order Question of Student Through Problem Based Learning at Grade X MIA 6 of SMA N 4 Surakarta

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    The research aims to enhance the Higher Order Question of student through problem based learning in Biology at Grade X MIA 6 of SMA N 4 Surakarta. The research was a four-cycle action research conducted in academic year 2014/2015. All questions were analyzed based on revised Bloom Taxonomy. Data were validated using triangulation method. The result of the research showed that problem based learning effectively enhance student\u27s High Order Question (C4-C6). The percentage of each High Order Question (C4-C6) in pre cycle were 0%. The percentage of C4 type question at first cycle (73,14%), second cycle (52,13%), third cycle (56,05%), and fourth cycle (58,42%). The percentage of each High Order Question (C4-C6) in pre cycle were 0%. The percentage of C5 type question at first cycle (18,37%), second cycle (9,57%), third cycle (10,30%), and fourth cycle (58,42%). The percentage of each High Order Question (C4-C6) in pre cycle were 0%. The percentage of C6 type question at first cycle (8,16%), second cycle (38,30%), third cycle (41,18%) and fourth cycle (25,74%)

    The 2nd Workshop on Maritime Computer Vision (MaCVi) 2024

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    The 2nd Workshop on Maritime Computer Vision (MaCVi) 2024 addresses maritime computer vision for Unmanned Aerial Vehicles (UAV) and Unmanned Surface Vehicles (USV). Three challenges categories are considered: (i) UAV-based Maritime Object Tracking with Re-identification, (ii) USV-based Maritime Obstacle Segmentation and Detection, (iii) USV-based Maritime Boat Tracking. The USV-based Maritime Obstacle Segmentation and Detection features three sub-challenges, including a new embedded challenge addressing efficicent inference on real-world embedded devices. This report offers a comprehensive overview of the findings from the challenges. We provide both statistical and qualitative analyses, evaluating trends from over 195 submissions. All datasets, evaluation code, and the leaderboard are available to the public at https://macvi.org/workshop/macvi24.Comment: Part of 2nd Workshop on Maritime Computer Vision (MaCVi) 2024 IEEE Xplore submission as part of WACV 202

    Nanoparticles for Applications in Cellular Imaging

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    In the following review we discuss several types of nanoparticles (such as TiO2, quantum dots, and gold nanoparticles) and their impact on the ability to image biological components in fixed cells. The review also discusses factors influencing nanoparticle imaging and uptake in live cells in vitro. Due to their unique size-dependent properties nanoparticles offer numerous advantages over traditional dyes and proteins. For example, the photostability, narrow emission peak, and ability to rationally modify both the size and surface chemistry of Quantum Dots allow for simultaneous analyses of multiple targets within the same cell. On the other hand, the surface characteristics of nanometer sized TiO2allow efficient conjugation to nucleic acids which enables their retention in specific subcellular compartments. We discuss cellular uptake mechanisms for the internalization of nanoparticles and studies showing the influence of nanoparticle size and charge and the cell type targeted on nanoparticle uptake. The predominant nanoparticle uptake mechanisms include clathrin-dependent mechanisms, macropinocytosis, and phagocytosis

    An efficient strategy for circulating tumor cell detection: surface-enhanced Raman spectroscopy

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    Circulating tumor cells (CTCs) are circulating cancer cells that shed from tumor tissue into blood vessels and circulate in the blood to invade other organs, which results in fatal metastases. The CTCs in human peripheral blood are the main cause of death in most cancer patients. The detection of CTCs is of great scientific significance and clinical application value for early diagnosis, rapid evaluation of the treatment effect, in vivo drug resistance testing, individualized treatment, tumor recurrence detection and survival time judgment, etc. The surface-enhanced Raman scattering (SERS) method possesses the features of remarkable detection sensitivity, a non-destructive nature, label-free detection, a quick spectrum response and a molecular fingerprint spectrum, which give it great potential in the detection field. In the past decade, SERS technology serving as a bioprobe has been increasingly applied to detect and analyze biological components due to its unique detection advantages. Here, we present an overview of SERS biosensing substrates and recent achievements in detecting CTCs using high-sensitivity SERS platforms, and provide a unique perspective on the design and application of high-performance SERS platforms for CTC detection, especially using non-metal materials

    Research on the effect of drilling fluid’s pH value on the coal’s wettability

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    Abstract Drilling fluid contacts with the surface of coal and fractures fully during the drilling process for CBM, its pH value has direct impact on the wettability of coal, affecting the seepage of CBM further. Therefore, the research about the effect of drilling fluid’s pH value on the coal’s wettability has important practical significance. The influence law of drilling fluid’s pH value on the coal’s wettability was studied through lots of experiments, the results showed that the wettability was related to the pH value of drilling fluid, decreases firstly, increases secondly and decreases at last, the coal’s hydrophilicity was the weakest at the pH value of 9, and the hydrophilicity of coal was weaken further after the addition of surfactants. The conclusions provide strong technical guidance for selecting drilling fluid and optimizing fluid performance, and it helps to protect the reservoir and increase CBM production

    Applications of Iron Oxide-Based Magnetic Nanoparticles in the Diagnosis and Treatment of Bacterial Infections

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    Applications of Iron Oxide-Based Magnetic Nanoparticles in the Diagnosis and Treatment of Bacterial Infection
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