801 research outputs found
Friction and wear properties of TiCN coatings sliding against SiC and steel balls in air and water
No full textThe TiCN coatings were deposited on WC cemented carbides using enhanced cathodic arc magnetron sputtering. The topography of TiCN coatings were observed using scanning electron microscopy (SEM), the composition and structure of TiCN coatings were analyzed by energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). The friction and wear properties of TiCN coatings sliding against SiC and steel balls in air and water were investigated using ball-on-disk tribometer. The results showed that the TiCN coatings had a strong (111) preferred orientation. The friction coefficient and the specific wear rates of the TiCN/SiC tribopairs in air were higher than those in water. When the TiCN coatings slid against SiC balls in water, the friction coefficient and the specific wear rates first decreased, and then increased with the normal load, but decreased linearly with the sliding velocity. The lowest friction coefficient of 0.171 was obtained at 3 N and 0.4 m/s, while the lowest specific wear rate of the TiCN coatings was 2.3 × 10? 6mm3/Nm at 6 N and 0.1 m/s. The TiCN coatings were worn out when the normal loads were higher than 6 N. When the TiCN coatings slid against the SUJ2 and SUS440C balls in water, the friction coefficient increased to 0.271 and 1.026 respectively. The EDS analysis showed that Fe and O elements existed on the wear track. This indicated that the tribochemical reaction occurred at the friction contact area
Comparison of tribological properties of CrN, TiCN and TiAlN coatings sliding against SiC balls in water
No full textCrN, TiCN and TiAlN coatings were deposited on WC cemented carbide disks using enhanced cathodic arc magnetron sputtering and their topographies and structures were observed and analyzed using scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. The friction and wear properties of CrN, TiCN and TiAlN coatings sliding against SiC balls in water were investigated and compared synthetically using ball-on-disk tribometer. The results showed that the CrN/SiC tribopairs showed the lowest friction coefficient of 0.076, while the TiCN/SiC tribopairs displayed the highest friction coefficient of 0.264. For the CrN/SiC tribopairs the specific wear rate of CrN coatings was lowest while that of SiC balls became highest. But for the TiAlN(TiCN)/SiC tribopairs, the specific wear rate of TiAlN coatings was highest while that of SiC balls for the TiCN/SiC tribopairs became lowest. This indicated that the friction and wear behaviors of nitride coatings/SiC balls tribo-systems in water were more strongly influenced by the anti-oxidative ability of tribomaterials in water than by their mechanical properties
Single-beam phase retrieval with partially coherent light illumination
No full textA single-beam phase retrieval method with partially coherent illumination is proposed. By using an obverse and reverse iterative (ORI) algorithm, objects can be reconstructed within less time by recording a sequence of diffraction patterns at different axial planes under partially coherent light illumination. Partially coherent light illumination reduces coherent noise and the number of diffraction patterns needed for reconstruction. Thus, the whole process is fast and has high immunity to external perturbation due to the reference-less configuration. Both simulation and experimental results are presented to demonstrate the feasibility of the proposed approach
Speckle-correlation microscopic imaging through scattering medium
No full text
In this paper we are presenting a non-invasive and lensless method to utilize a scattering media for microscopic imaging. Thanks to its lens-like property, we can adjust the magnification and resolution of the system and reconstruct the microscopic object using phase retrieval technique from the autocorrelation of a single-shot speckle intensity distribution. © OSA 2016.</p
Comparison of tribological and electrochemical properties of TiN, CrN, TiAlN and a-C:H coatings in simulated body fluid
No full textTiN, CrN, TiAlN and a-C:H coatings have been used for wear reduction, but a thorough comparison of their erosion and abrasion characteristics in simulated body fluid (SBF) has never been reported in existent literature. In this study, the tribological and electrochemical performance of these coatings in SBF was investigated and compared. As a result, the TiAlN coating presented the worst tribological and electrochemical properties because of abundant products from hydration. On the contrary, due to the generation of a favorable tribochemical product (Cr2O3), the CrN coating exhibited superior characteristics of tribology and electrochemistry. The a-C:H coating also showed outstanding corrosion resistance, but premature delamination occurred in aqueous environment which might limit its application. Thus, the CrN coating was found to be the most favorable protection coating in SBF from a comprehensive viewpoint
Descriptions of four new dextral land snails of the genus Camaena (Gastropoda, Eupulmonata, Camaenidae) from south China
No full textIn this study, four new dextral camaenid from China are reported, based on shell morphology, reproductive system anatomy, and molecular phylogenetic analyses: Camaena funingensis Zhou, Wang & Lin, sp. nov., Camaena gaolongensis Zhou, Wang & Lin, sp. nov., Camaena maguanensis Zhou, Wang & Hu, sp. nov., and Camaena yulinensis Zhou, Wang & Hu, sp. nov. Detailed descriptions of the morphological characteristics including shells and genitalia, DNA sequences, and living environments of the four new species are provided, with further comparisons with congeners
Threshold automatic selection hybrid phase unwrapping algorithm for digital holographic microscopy
No full textConventional quality-guided (QG) phase unwrapping algorithm is hard to be applied to digital holographic microscopy because of the long execution time. In this paper, we present a threshold automatic selection hybrid phase unwrapping algorithm that combines the existing QG algorithm and the flood-filled (FF) algorithm to solve this problem. The original wrapped phase map is divided into high- and low-quality sub-maps by selecting a threshold automatically, and then the FF and QG unwrapping algorithms are used in each level to unwrap the phase, respectively. The feasibility of the proposed method is proved by experimental results, and the execution speed is shown to be much faster than that of the original QG unwrapping algorithm.
SYK-targeted dendritic cell-mediated cytotoxic T lymphocytes enhance the effect of immunotherapy on retinoblastoma
No full textPurpose: Retinoblastoma (RB) is the most common primary intraocular tumor in children. Chemotherapy is currently the main method of RB treatment. Unfortunately, RB often becomes chemoresistant and turns lethal. Here, we used in vitro cell immunotherapy to explore whether adoptive immunotherapy could be used as a potential treatment for RB. We focused on spleen tyrosine kinase (SYK), which is significantly upregulated in RB cells and serves as a marker for RB cells. Methods: Using lentiviruses, we genetically modified dendritic cells (DCs) to express and present the SYK peptide antigen to cytotoxic T lymphocytes (CTLs) in vitro. We used SYK-negative cell lines (MDA-MB-231, MCF-10A, and hTERT-RPE1) and SYK-positive cell lines (MCF-7 and RB-Y79) to evaluate the specificity and cytotoxicity of DC presented CTLs using FACS, live-cell imaging, and RNA interference. Results: The cytotoxicity of CTLs induced by SYK-overexpressing DCs (SYK-DC–CTLs) was enhanced more than three times in SYK-positive cell lines compared with SYK-negative cell lines. DCs primed with SYK could drive CTL cytotoxicity against SYK-positive cell lines but not against SYK-negative cell lines. Moreover, SYK-silenced RB-Y79 cells successfully evaded the cytotoxic attack from SYK-DC–CTLs. However, SYK-DC–CTLs could target SYK overexpressed hTERT-RPE1 cells, suggesting that SYK is a specific antigen for RB. Furthermore, SYK-DC–CTL exhibited specific cytotoxicity against carboplatin-resistant RB-Y79 cells in vitro. Conclusions: Our data showed that SYK could be a potential immunotherapy target mediated by DCs. We propose SYK as a candidate target for treatment of chemoresistant RB.Fil: Chen, Xuemei. Xi'an Jiaotong University; ChinaFil: Kunda, Patricia Elena. Instituto Universitario de Ciencias Biomédicas de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba; ArgentinaFil: Lin, Jianwei. Shenzhen University; ChinaFil: Zhou, Meiling. Shenzhen Luohu Peoples Hospital; China. Shenzhen University; ChinaFil: Huang, Jinghan. Shenzhen Luohu Peoples Hospital; ChinaFil: Zhang, Huqin. Xi'an Jiaotong University; ChinaFil: Liu, Tao. Shenzhen University; China. Shenzhen Luohu Peoples Hospital; Chin
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