Digital Particle Holographic System for Measurements of Particle Field Characteristics

( Yan Yang ),( Bo Seon Kang ) 한국액체미립화학회 2010 한국액체미립화학회 학술강연회 논문집 Vol.2010 No.-

This study focuses on the development of in-line digital particle holographic system and its application to particle fields. The double exposure hologram recording system was established and digital holograms can be recorded in a short time interval. The object distance, which is one of important parameters in hologram recording, was discussed and its optimal value was obtained based on theory and experiments. For hologram reconstruction, two typical methods were compared and better one, the convolution method, was chosen. The correlation coefficient method was presented for focal plane determination of particles and the feasibility of this method was verified. For image processing of holograms and reconstruction images, the Wiener filter was adopted to remove noise and improve quality. The two-threshold and image segmentation methods were used in binary image transformation. For velocity extraction, the conventional cross-correlation method was adopted for flow field measurements (as DHPIV) and the method of neighboring match probability was used in spray field measurements (as DHPTV). The developed system was applied to spray field, channel flow field, and rotating flow field. The results prove the feasibility of digital particle holography as a good measurement tool for particle fields.

Clinical Significance of MRI Contrast Enhancement of the Oculomotor Nerve in Ischemic Isolated Oculomotor Nerve Palsy

Yan Yang,Chuntao Lai,Fei Yan,Jiawei Wang 대한신경과학회 2020 Journal of Clinical Neurology Vol.16 No.4

Background and Purpose Contrast enhancement of the oculomotor nerve in MRI was recently noticed in patients with clinical ischemic isolated oculomotor nerve palsy (iIONP). The opinions about whether this is a sign of inflammation and whether or not to administer steroids vary between doctors. The study aimed to determine the associations between this enhancement and vascular-disease risk factors (VRFs) and inflammatory factors in iIONP patients. Methods The study recruited patients who had experienced iIONP during the previous 2 years. They were divided into groups A and B based on whether or not they exhibited an enhanced oculomotor nerve in MRI of the cavernous sinus using thin-section, fat-suppressed, and contrast-enhanced sequences. VRFs, inflammatory factors, and improvement scores were compared between the two groups. Results Most (71.1%) of the 45 included iIONP patients had enhanced oculomotor nerves in MRI. VRFs, periorbital pain, elevated C-reactive protein and erythrocyte sedimentation rate, the neutrophil-to-lymphocyte ratio, and the platelet-to-lymphocyte ratio were not significantly associated with the enhancement. Four of the five patients in group A exhibited an elevated cerebrospinal fluid (CSF) IgG synthesis rate. The improvement score of eight patients who received 80 mg of methylprednisolone in addition to the routine therapy was not significantly different from the scores of the other patients (p=0.485). Conclusions More than half of the iIONP patients had an enhanced oculomotor nerve in MRI. A few of them also had elevated CSF IgG synthesis rate, but no further evidence for inflammation was found. The administration of steroids seemed to have no benefit other than increasing the blood glucose level.

Depth of Focus Determination in Digital Particle Holography

( Yan Yang ),( Bo Seon Kang ) 한국액체미립화학회 2008 한국액체미립화학회 학술강연회 논문집 Vol.2008 No.-

Effects of compound traditional Astragalus and Salvia Miltiorrhiza extract on acute and chronic hepatic injury

Yan Yang,Xiaoxiang Zhang,Xin Liu,Chao Wu,Min-Zhu Chen 셀메드 세포교정의약학회 2013 셀메드 (CellMed) Vol.3 No.2

Previous reports showed that Compound Astragalus and Salvia miltiorrhiza extract (CASE), which was mainly composed of astragalosides, astragalus polysaccharide and salvianolic acids, inhibited hepatic fibrosis by mediating transforming growth factor-β (TGF-β)/Smad signaling. Our aim was to examine the effects of CASE on D-galactosamine (D-GalN) treated liver injury in mice and carbon tetrachloride (CCl4)-induced liver fibrosis in rats. CASE was administered to mice with D-GalN-induced liver injury and to rats with CCl4-induced liver fibrosis, respectively. Liver injury was routinely evaluated by relative liver weight, serum levels of ALT, AST, hyaluronic acid (HA), hepatic malondialdehyde (MDA) content, superoxide dismutase (SOD) activity, hydroxyproline (HYP) and histopathologic changes. Treatment of mice with CASE (60, 120, and 240 mg/kg, ig) significantly lowered ALT, relative liver weight, and MDA levels when compared with D-GalN treated mice. CASE (120, 240 mg/kg) significantly lowered ALT, AST, HA, HYP, and MDA levels against CCl4 treated rats. Decreased SOD level was reversed with CASE treatment. Upon histopathological examination, CASE treatment had significantly inhibitory effect on the progression of hepatic fibrosis in rats. These results indicate that CASE might be effective in treatment and prevention of acute and chronic hepatic injury due to its antioxidant activity.

Bioactive polysaccharides isolated from the fruiting bodies of Phellinus sp.

Yan Yang,Jingsong Zhang,Yanfang Liu,Qingbo Wang,Qingjiu Tang,Shuai Zhou 한국버섯학회 2010 한국버섯학회 국제학술대회 Vol.6 No.-

Synthesis of a Novel Side Chain Liquid Crystalline-Main Chain Liquid Crystalline Block Copolymer by Radical / Cation Transformation Polymerization

Yan Yang,Hai-Qing Guo 한국고분자학회 2012 한국고분자학회 학술대회 연구논문 초록집 Vol.2012 No.4

Inter-Vehicle Cooperation Channel Estimation for IEEE802.11p V2I Communications

Yan Yang,Fei Dan,Shuping Dang 한국통신학회 2017 Journal of communications and networks Vol.19 No.3

The impact of imperfect channel state information (CSI) is particularly serious in vehicle-to-infrastructure (V2I) and vehicle-to-vehicle (V2V) communications.~Considering the sparse characteristics of V2I channels, this paper proposes an inter-vehicle cooperation channel estimation (IVC-CE) method at the IEEE 802.11p physical layer, and the effects of outdated CSI can be mitigated by single or multiple vehicle measurements.~With these assisted measurements, we can develop an interpolation-assisted channel estimation technique to obtain accurate CSI.~To select optimum measurements from a group of channel estimates, we utilize the position and velocity of a vehicle as a priori information.~We investigate the validity of the IVC-CE technique with the traditional linear minimum mean-squared error algorithm and present a scalable data transmission scheme at the physical layer.~The performance of IVC-CE is analyzed by its mean squared error and bit error rate in a fast fading channel environment. Simulations and numerical results show the merits of the proposed techniques, which can significantly enhance estimation performance and support safety related data transmissions for vehicular ad hoc networks.

Experimental study on the compression of concrete filled steel tubular latticed columns with variable cross section

Yan Yang,Jun Zhou,Jiangang Wei,Lei Huang,Qingxiong Wu,Bao-chun Chen 국제구조공학회 2016 Steel and Composite Structures, An International J Vol.22 No.3

The effects of slenderness ratio, eccentricity and column slope on the load-carrying capacities and failure modes of variable and uniform concrete filled steel tubular (CFST) latticed columns under axial and eccentric compression were investigated and compared in this study. The results clearly show that all the CFST latticed columns with variable cross section exhibit an overall failure, which is similar to that of CFST latticed columns with a uniform cross section. The load-carrying capacity decreases with the increase of the slenderness ratio or the eccentricity. For 2-m specimens with a slenderness ratio of 9, the ultimate load-carrying capacity is increased by 3% and 5% for variable CFST latticed columns with a slope of 1:40 and 1:20 as compared with that of uniform CFST latticed columns, respectively. For the eccentrically compressed variable CFST latticed columns, the strain of the columns at the loading side, as well as the difference in the strain, increases from the bottom to the cap, and a more significant increase in strain is observed in the cross section closer to the column cap.

Parametric Analysis of Digital Particle Holography for Spray Droplets

( Yan Yang ),( Bo Seon Kang ) 한국액체미립화학회 2007 한국액체미립화학회 학술강연회 논문집 Vol.2007 No.-

Bioactive polysaccharides isolated from the fruiting bodies of Phellinus sp.

Yan Yang,Jingsong Zhang,Yanfang Liu,Qingbo Wang,Qingjiu Tang,Shuai Zhou 한국버섯학회 2010 한국버섯학회지 Vol.8 No.4

Phellinus sp. are assigned to the Basidiomycotina, Hymenomycetes, Aphyllophorales and Hymenochaetaceae, and have been shown containing various bioactive substances including triterpenoids, polysaccharides and flavones[1]. Traditional Chinese herbalists believe that Phellinus species are effective in treating many gynecopathic ailments[2] and are also reported to exhibit other pharmacological functions including tumor cell inhibition, antioxidant activity and anti-hepatic fibrosis effects[3]. Polysaccharides of Phellinus sp. has been reported to possess antitumor activities and inhibit tumor recrudescence and metastasis. There are little studies comparing the chemical composition and biological activities difference among polysaccharides from different Phellinus sp and little report about the pure polysaccharide structure analysis. In this study, eight kinds of crude polysaccharides were extracted from Phellinus fruit bodies and their chemical composition and bioactivities were researched. The polysaccharide and protein contents of eight crude polysaccharides had a certain extent differences. Monosaccharide composition and content of amino acids also existed some differences in eight crude polysaccharides. Eight different polysaccharides all showed enhancing splenocyte proliferation effect in vitro. PB-10P and JSHP had high cell proliferation rates with 50㎍/ml concentrations. The results indicated in some extent the immune activity of crude polysaccharides were correlation with the polysaccharide and protein content and composition of each sample. The crude polysaccharides of P. igniarius were further isolated and purified using DEAE Sepharose F. F. and gel-filtration chromatography (Sephacryl S-100-500 )repeatedly. Five water-soluble homogeneous polysaccharides (P60w1、P60s1、P1SP1、P10SP1and P100SP1) were obtained. Lack of absorption at 280 nm and 260 nm by UV scanning indicated that contained no protein and nucleic acid. HPLC produced a single symmetrical peak, indicated homogeneity and their molecular weigh were 1.71×104 Da、2.07×104 Da、1.48×104 Da、2.20×104 Da and 2.56×104 Da respectively. Structural of P60w-1 were determined using sugar and methylation analysis combined with 1H and 13C NMR spectroscopy, including COSY, TOCSY, NOESY, HSQC and HMBC experiments. The effect of P60w-1 on tumor growth was examined using subcutaneously transplanted H22 and Lewis Lung Carcinoma (LLC) tumor mouse models. Cyclophosphamide or Coriolus versicolor polysaccharopeptide served as positive controls in evaluating tumor response. Results showed that P60w-1 at the most effective dose of 100 mg/kg inhibited the growth of H22 and LLC by 48% and 37%, respectively.