379 results on '"Xiaoyun Sun"'
Search Results
352. Current measurement for dynamic Idd test.
- Author
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Xiaoyun Sun and Vinnakota, B.
- Published
- 2001
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353. Neuroimaging. Dyna-CT-assisted percutaneous microballoon compression for trigeminal neuralgia.
- Author
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Xiaochuan Huo, Xiaoyun Sun, Zhenxing Zhang, Wenshi Guo, Ning Guan, and Junsheng Luo
- Subjects
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COMPRESSION therapy , *TRIGEMINAL neuralgia treatment , *TOMOGRAPHY , *NEUROSURGERY , *ACADEMIC medical centers , *NEURORADIOLOGY , *HEALTH outcome assessment , *SAFETY , *TREATMENT effectiveness , *EQUIPMENT & supplies - Abstract
Background Percutaneous microballoon compression (PMC) for trigeminal neuralgia (TN) is a well-established technique. However, complications from cannulating the foramen ovale (FO) have been reported because direct puncture of the FO is sometimes difficult. Here we report our experience with Dyna-CT-assisted PMC for TN in cannulating the FO and determining the position and volume of the balloon. Methods Dyna-CT-assisted PMC was performed for image reconstruction in 16 cases. The optimal working projection was generated and further fluoroscopic data were used to determine the relationship of the needle with the FO during puncture. The balloon position and three-dimensional shape were verified with Dyna-CT during balloon compression and the balloon volume and puncture angle were also calculated. Patients' prognosis is discussed. Results Dyna-CT allows quick, safe and easy cannulation of the FO. It provided three-dimensional images which were more elaborate than the classic ‘pear shape’ images for determining correct positioning in 16 cases. The volume of the inflated balloon ranged from 568.2 mm3 to 891.4 mm3 (average 769.5 mm3). The angle of introducing the cannula ranged from 15.32° to 35.48° rotation to the midline (average 25.18°) and 38.47° - 51.89° angulation to the Reid line (average 46.17°). All the patients were pain-free after PMC. Four patients had resolvable masseter weakness and fine touch loss. No recurrence of TN was reported on follow-up. Conclusions Dyna-CT performed by digital subtraction angiography assists PMC in three ways: (1) the FO can be better visualized independent of the patient' s position; (2) needle correction or insertion can be performed much more easily because of the direct fluoroscopic control; and (3) the needle position, balloon position, balloon con figuration and the volume of the in flated balloon is more reliably determined. The use of Dyna-CT-assisted PMC has a low incidence of complications and a good prognosis. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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- View/download PDF
354. Subsets of regulatory T cells and their roles in allergy.
- Author
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Huiyun Zhang, Hui Kong, Xiaoning Zeng, Lianyi Guo, Xiaoyun Sun, and Shaoheng He
- Subjects
T cells ,MAST cells ,ALLERGIES ,IMMUNE system ,SENSITIZATION (Neuropsychology) - Abstract
In recent years, it is recognized that acquired immunity is controlled by regulatory T cell (Treg). Since fundamental pathophysiological changes of allergy are mainly caused by hyperresponsiveness of immune system to allergens that acquires after birth, Tregs likely play key roles in the pathogenesis of allergy, particularly during the sensitization phase. However, accumulated information indicate that there are several distinctive subtypes of Tregs in man, and each of them seems to play different role in controlling immune system, which complicates the involvement of Tregs in allergy. The aim of the present study is to attempt to classify subtypes of Tregs and summarize their roles in allergy. Tregs should include natural Tregs (nTreg) including inducible costimulator (ICOS)(+) Tregs, inducible/adaptive Tregs (iTreg), interleukin (IL)-10-producing type 1 Tregs (Tr1 cells), CD8(+) Tregs and IL-17-producing Tregs. These cells share some common features including expression of Foxp3 (except for Tr1 cells), and secretion of inhibitory cytokine IL10 and/or TGF-β. Furthermore, it is noticeable that Tregs likely contribute to allergic disorders such as dermatitis and airway inflammation, and play a crucial role in the treatment of allergy through their actions on suppression of effector T cells and inhibition of activation of mast cells and basophils. Modulation of functions of Tregs may provide a novel strategy to prevent and treat allergic diseases. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
355. Large area high density quantized magnetic disks fabricated using nanoimprint lithography
- Author
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Wei Zhang, Xiaoyun Sun, Stephen Y. Chou, Wei Wu, Linshu Kong, Bo Cui, and Lei Zhuang
- Subjects
Materials science ,business.industry ,General Engineering ,Polishing ,Grating ,Nanoimprint lithography ,law.invention ,Optics ,law ,Chemical-mechanical planarization ,Perpendicular ,Magnetic force microscope ,Photolithography ,business ,Electroplating - Abstract
A new low-cost, high throughput method was developed for fabricating large area quantized magnetic disks (QMDs) using nanoimprint lithography (NIL), electroplating, and chemical mechanical polishing. Perpendicular QMDs with a density of 18 Gbit/in.2 and good uniformity over an area of 4 cm×4 cm (total 45 Gbit) have been achieved, as well as longitudinal QMDs of 30 Gbit/in.2 The NIL molds for the perpendicular QMDs were fabricated using double NIL with a grating mold. The magnetic properties of both types of QMDs were studied by magnetic force microscopy.
- Published
- 1998
356. Multilayer resist methods for nanoimprint lithography on nonflat surfaces
- Author
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Lei Zhuang, Xiaoyun Sun, Stephen Y. Chou, and Wei Zhang
- Subjects
Materials science ,Resist ,law ,Feature (computer vision) ,General Engineering ,Nanotechnology ,X-ray lithography ,Lithography ,Next-generation lithography ,Nanoimprint lithography ,law.invention - Abstract
Five multilayer resist methods (three positive tones and two negative tones) have been devised for nanoimprint lithography on nonflat surfaces. Three of the methods have been demonstrated experimentally on a SiO2 surface with 100 nm deep sharp steps. The advantages and disadvantages of each method are discussed. Our results should be applicable to nanoimprint lithography with 10 nm feature size on nonflat surfaces.
- Published
- 1998
357. Position effect on FGF13 associated with X-linked congenital generalized hypertrichosis.
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DeStefano, Gina M., Fantauzzo, Katherine A., Petukhova, Lynn, Kurban, Mazen, Tadin-Strapps, Marija, Levy, Brynn, Warburton, Dorothy, Cirulli, Elizabeth T., Yujun Han, Xiaoyun Sun, Yufeng Shen, Shirazi, Maryam, Jobanputra, Vaidehi, Cepeda-Valdes, Rodrigo, Salas-Alanis, Julio Cesar, and Christiano, Angela M.
- Subjects
FIBROBLAST growth factors ,HYPERTRICHOSIS ,BODY hair ,OLIGONUCLEOTIDE arrays ,IMMUNOFLUORESCENCE ,HAIR follicle physiology ,GENETICS - Abstract
X-linked congenital generalized hypertrichosis (Online Mendelian Inheritance in Man 307150) is an extremely rare condition of hair overgrowth on different body sites. We previously reported linkage in a large Mexican family with X- linked congenital generalized hypertrichosis cosegregating with deafness and with dental and palate anomalies to Xq24-27. Using SNP oligonucleotide microarray analysis and whole-genome sequencing, we identified a 389-kb interchromosomal insertion at an extragenic palindrome site at Xq27.1 that completely cosegregates with the disease. Among the genes surrounding the insertion, we found that Fibroblast Growth Factor 13 (FGF13) mRNA levels were significantly reduced in affected individuals, and immunofluorescence staining revealed a striking decrease in FGF13 localization throughout the outer root sheath of affected hair follicles. Taken together, our findings suggest a role for FGF13 in hair follicle growth and in the hair cycle. [ABSTRACT FROM AUTHOR]
- Published
- 2013
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358. Mitigation of Murine Focal Cerebral Ischemia by the Hypocretin/Orexin System is Associated With Reduced Inflammation.
- Author
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Xiaoxing Xiong, White, Robin E., Lijun Xu, Liya Yang, Xiaoyun Sun, Bende Zou, Pascual, Conrado, Sakurai, Takeshi, Giffard, Rona G., and Xinmin (Simon) Xie
- Published
- 2013
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359. Antibodies against outer-capsid proteins of grass carp reovirus expressed in E. coli are capable of neutralizing viral infectivity.
- Author
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Ling Shao, Xiaoyun Sun, and Qin Fang
- Subjects
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CTENOPHARYNGODON idella , *IMMUNOGLOBULINS , *ESCHERICHIA coli , *VACCINATION , *BIOMOLECULES - Abstract
Background: Grass carp reovirus (GCRV), which causes severe infectious outbreaks of hemorrhagic disease in aquatic animals, is a highly pathogenic agent in the Aquareovirus genus of family Reoviridae. The outer capsid shell of GCRV, composed of the VP5-VP7 protein complex, is believed to be involved in cell entry. The objective of this study was to produce a major neutralization antibody for mitigating GCRV infection. Results: Recombinant plasmids of GCRV outer capsid proteins VP5 and VP7 were constructed and expressed in prokaryotic cells in our previous work. In this study, we prepared GCRV Antibody (Ab), VP5Ab and VP7Ab generated from purified native GCRV, recombinant VP5 and VP7 respectively. Immunoblotting analysis showed that the prepared antibodies were specific to its antigens. In addition, combined plaque and cytopathic effect (CPE)- based TCID50 (50% tissue culture infective dose) assays showed that both VP5Ab and VP7Ab were capable of neutralizing viral infectivity. Particularly, the neutralizing activity of VP7Ab was 3 times higher than that of VP5Ab, suggesting that VP7 might be a dominating epitope. Moreover, the combination of VP5Ab and VP7Ab appeared to enhance GCRV neutralizing capacity. Conclusions: The results presented in this study indicated that VP7 protein was the major epitope of GCRV. Furthermore, VP5Ab and VP7Ab in combination presented an enhanced capacity to neutralize the GCRV particle, suggesting that the VP5 and VP7 proteins may cooperate with each other during virus cell entry. The data can be used not only to further define the surface epitope domain of GCRV but may also be applicable in the designing of vaccines. [ABSTRACT FROM AUTHOR]
- Published
- 2011
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360. Functional investigation of grass carp reovirus nonstructural protein NS80.
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Lin Cai, Xiaoyun Sun, Ling Shao, and Qin Fang
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CTENOPHARYNGODON idella , *REOVIRUSES , *MIRIDAE , *CYTOSKELETAL proteins , *ORTHOREOVIRUSES , *BIOINFORMATICS - Abstract
Background: Grass Carp Reovirus (GCRV), a highly virulent agent of aquatic animals, has an eleven segmented dsRNA genome encased in a multilayered capsid shell, which encodes twelve proteins including seven structural proteins (VP1-VP7), and five nonstructural proteins (NS80, NS38, NS31, NS26, and NS16). It has been suggested that the protein NS80 plays an important role in the viral replication cycle that is similar to that of its homologous protein μNS in the genus of Orthoreovirus. Results: As a step to understanding the basis of the part played by NS80 in GCRV replication and particle assembly, we used the yeast two-hybrid (Y2H) system to identify NS80 interactions with proteins NS38, VP4, and VP6 as well as NS80 and NS38 self-interactions, while no interactions appeared in the four protein pairs NS38-VP4, NS38-VP6, VP4-VP4, and VP4-VP6. Bioinformatic analyses of NS80 with its corresponding proteins were performed with all currently available homologous protein sequences in ARVs (avian reoviruses) and MRVs (mammalian reoviruses) to predict further potential functional domains of NS80 that are related to VFLS (viral factory-like structures) formation and other roles in viral replication. Two conserved regions spanning from aa (amino acid) residues of 388 to 433, and 562 to 580 were discovered in this study. The second conserved region with corresponding conserved residues Tyr565, His569, Cys571, Asn573, and Glu576 located between the two coiledcoils regions (aa ∼513-550 and aa ~615-690) in carboxyl-proximal terminus were supposed to be essential to form VFLS, so that aa residues ranging from 513 to 742 of NS80 was inferred to be the smallest region that is necessary for forming VFLS. The function of the first conserved region including Ala395, Gly419, Asp421, Pro422, Leu438, and Leu443 residues is unclear, but one-third of the amino-terminal region might be species specific, dominating interactions with other viral components. Conclusions: Our results in this study together with those from previous investigations indicate the protein NS80 might play a central role in VFLS formation and viral components recruitment in GCRV particle assembly, similar to the μNS protein in ARVs and MRVs. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
361. Neural network training techniques for a gold trading model.
- Author
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Brauner, E.O., Dayhoff, J.E., Xiaoyun Sun, and Hormby, S.
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- 1997
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362. CHINA'S ECONOMIC REFORM AND ITS OBSTACLES: CHALLENGES TO A LARGE-SCALE SOCIAL EXPERIMENT.
- Author
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Jixuan Hu and Xiaoyun Sun
- Subjects
ECONOMIC reform ,CYBERNETICS ,PEASANTS ,CHINESE economic policy ,SOCIAL change - Published
- 1990
363. Activation of Nrf2 by Microcystin-LR Provides Advantages for Liver Cancer Cell Growth.
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Nanqin Gan, Xiaoyun Sun, and Lirong Song
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MICROCYSTINS , *LIVER cancer , *CELL growth , *CELL proliferation , *ANTIOXIDANTS , *TRANSCRIPTION factors , *CANCER cells , *CARCINOGENESIS - Abstract
Microcystin-LR (MC-LR) is a potent heptapeptide hepatotoxin at high doses, but its underlying mechanism of promoting liver cell proliferation at low doses is unclear. The transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) is key in mediating the protective antioxidant response against various environmental toxicants, but emerging data suggest that constitutive activation of Nrf2 contributes to a malignant phenotype. The purpose of this study was to characterize the interactions and effects of Nrf2 activation on cell proliferation induced by MC-LR treatment. Treatment of HepG2 and Hep3B cells with MC-LR resulted in significant increases in Nrf2-ARE binding activities in the nuclear fractions and upregulation of its downstream genes HO-1and NQO1. A possible mechanism may be that MC-LR binds to the cytosolic regulator protein Keap1 to liberate Nrf2. Nrf2 knockdown inhibited MC-LR-induced cell proliferation and cell cycle progression. Together, these results indicate that MC-LR-induced upregulation of Nrf2 in cancer cells promotes liver cancer cell growth and suggest a positive role of Nrf2 in tumorigenesis. [ABSTRACT FROM AUTHOR]
- Published
- 2010
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364. Optimal and Spatial Analysis of Hormones, Degrading Enzymes and Isozyme Profiles in Tomato Pedicel Explants During Ethylene-Induced Abscission.
- Author
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Yanchang Wang, Tianlai Li, Hanyong Meng, and Xiaoyun Sun
- Published
- 2005
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365. Research Developments and Prospects on Microseismic Source Location in Mines.
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Jiulong Cheng, Guangdong Song, Xiaoyun Sun, Laifu Wen, and Fei Li
- Subjects
TIME reversal ,GEOPHONE ,DEEP learning - Abstract
Microseismic source location is the essential factor in microseismic monitoring technology, and its location precision has a large impact on the performance of the technique. Here, we discuss the problem of low-precision location identification for microseismic events in a mine, as may be obtained using conventional location methods that are based on arrival time. In this paper, microseismic location characteristics in mining are analyzed according to the characteristics of the mine's microseismic wavefield. We review research progress in mine-related microseismic source location methods in recent years, including the combination of the Geiger method with the linear method, combined microseismic event location method, optimization of relative location method, location method without pre-measured velocity, and location method without arrival time picking. The advantages and disadvantages of these methods are discussed, along with their feasible conditions. The influences of geophone distribution, first arrival time picking, and the velocity model on microseismic source location are analyzed, and measures are proposed to influence these factors. Approaches to solve the problem under study include adopting information fusion, combining and optimizing existing methods, and creating new methods to realize highprecision microseismic source location. Optimization of the velocity structure, along with applications of the time-reversal imaging technique, passive time-reversal mirror, and relative interferometric imaging, are expected to greatly improve microseismic location precision in mines. This paper also discusses the potential application of information fusion and deep learning methods in microseismic source location in mines. These new and innovative location methods for microseismic source location have extensive prospects for development. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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366. Application of RBF network with ant colony and fisher ratio to fault diagnosis of oil-immersed transformer.
- Author
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Aihua Li, Xiaoyun Sun, and Donghui Liu
- Published
- 2011
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367. Reduction of Eddy Current Losses in Power Cable Systems Based on Phase Optimization.
- Author
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Yongchun Liang, Zhongjie Wang, Jianye Liu, and Xiaoyun Sun
- Published
- 2010
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368. Mining sequential relations from multidimensional data sequence for prediction
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Heng Tang, Shaoyi Stephen LIAO, and Sherry Xiaoyun Sun
369. Subsets of regulatory T cells and their roles in allergy
- Author
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Xiaoning Zeng, Hui Kong, Shaoheng He, Huiyun Zhang, Lianyi Guo, and Xiaoyun Sun
- Subjects
TGF-β ,Allergy ,Regulatory T cell ,medicine.medical_treatment ,chemical and pharmacologic phenomena ,Review ,T-Lymphocytes, Regulatory ,General Biochemistry, Genetics and Molecular Biology ,Mast cell ,Immune system ,T-Lymphocyte Subsets ,medicine ,Hypersensitivity ,Humans ,Medicine(all) ,business.industry ,Biochemistry, Genetics and Molecular Biology(all) ,FOXP3 ,hemic and immune systems ,General Medicine ,Acquired immune system ,medicine.disease ,Interleukin 10 ,medicine.anatomical_structure ,Cytokine ,Immunology ,IL-10 ,business ,CD8 - Abstract
In recent years, it is recognized that acquired immunity is controlled by regulatory T cell (Treg). Since fundamental pathophysiological changes of allergy are mainly caused by hyperresponsiveness of immune system to allergens that acquires after birth, Tregs likely play key roles in the pathogenesis of allergy, particularly during the sensitization phase. However, accumulated information indicate that there are several distinctive subtypes of Tregs in man, and each of them seems to play different role in controlling immune system, which complicates the involvement of Tregs in allergy. The aim of the present study is to attempt to classify subtypes of Tregs and summarize their roles in allergy. Tregs should include natural Tregs (nTreg) including inducible costimulator (ICOS)(+) Tregs, inducible/adaptive Tregs (iTreg), interleukin (IL)-10-producing type 1 Tregs (Tr1 cells), CD8(+) Tregs and IL-17-producing Tregs. These cells share some common features including expression of Foxp3 (except for Tr1 cells), and secretion of inhibitory cytokine IL-10 and/or TGF-β. Furthermore, it is noticeable that Tregs likely contribute to allergic disorders such as dermatitis and airway inflammation, and play a crucial role in the treatment of allergy through their actions on suppression of effector T cells and inhibition of activation of mast cells and basophils. Modulation of functions of Tregs may provide a novel strategy to prevent and treat allergic diseases.
- Full Text
- View/download PDF
370. Quantitative characterization and analysis of the dynamic NF-κB response in microglia
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Xiaoyun Sun, John F. Emery, Mustafa Khammash, Patrick W. Sheppard, and Rona G. Giffard
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IκB kinase ,Biology ,lcsh:Computer applications to medicine. Medical informatics ,Biochemistry ,Brain Ischemia ,Cell Line ,Mice ,chemistry.chemical_compound ,Structural Biology ,Negative feedback ,medicine ,Animals ,lcsh:QH301-705.5 ,Transcription factor ,Molecular Biology ,Inflammation ,Regulation of gene expression ,Microglia ,Tumor Necrosis Factor-alpha ,Applied Mathematics ,NF-kappa B ,Transcription Factor RelA ,NF-κB ,NFKB1 ,I-kappa B Kinase ,Computer Science Applications ,medicine.anatomical_structure ,lcsh:Biology (General) ,Gene Expression Regulation ,chemistry ,Immunology ,lcsh:R858-859.7 ,Cytokines ,Signal transduction ,Neuroscience ,Signal Transduction ,Research Article - Abstract
Background Activation of the NF-κB transcription factor and its associated gene expression in microglia is a key component in the response to brain injury. Its activation is dynamic and is part of a network of biochemical species with multiple feedback regulatory mechanisms. Mathematical modeling, which has been instrumental for understanding the NF-κB response in other cell types, offers a valuable tool to investigate the regulation of NF-κB activation in microglia at a systems level. Results We quantify the dynamic response of NF-κB activation and activation of the upstream kinase IKK using ELISA measurements of a microglial cell line following treatment with the pro-inflammatory cytokine TNFα. A new mathematical model is developed based on these data sets using a modular procedure that exploits the feedback structure of the network. We show that the new model requires previously unmodeled dynamics involved in the stimulus-induced degradation of the inhibitor IκBα in order to properly describe microglial NF-κB activation in a statistically consistent manner. This suggests a more prominent role for the ubiquitin-proteasome system in regulating the activation of NF-κB to inflammatory stimuli. We also find that the introduction of nonlinearities in the kinetics of IKK activation and inactivation is essential for proper characterization of transient IKK activity and corresponds to known biological mechanisms. Numerical analyses of the model highlight key regulators of the microglial NF-κB response, as well as those governing IKK activation. Results illustrate the dynamic regulatory mechanisms and the robust yet fragile nature of the negative feedback regulated network. Conclusions We have developed a new mathematical model that incorporates previously unmodeled dynamics to characterize the dynamic response of the NF-κB signaling network in microglia. This model is the first of its kind for microglia and provides a tool for the quantitative, systems level study the dynamic cellular response to inflammatory stimuli.
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371. PPIRank - an advanced method for ranking protein-protein interations in TAP/MS data
- Author
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Pengyu Hong, Xiaoyun Sun, Meghana M. Kulkarni, Norbert Perrimon, and Young Guen Kwon
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Tandem affinity purification ,Computer science ,Protein protein ,Research ,Spectral Counts ,Computational biology ,computer.software_genre ,Proteomics ,Biochemistry ,Ranking (information retrieval) ,Protein-Protein Interaction ,Identification (information) ,Data analysis ,False positive paradox ,Data mining ,Computational analysis ,TAP/MS ,computer ,Molecular Biology - Abstract
Background: Tandem affinity purification coupled with mass-spectrometry (TAP/MS) analysis is a popular method for the identification of novel endogenous protein-protein interactions (PPIs) in large-scale. Computational analysis of TAP/MS data is a critical step, particularly for high-throughput datasets, yet it remains challenging due to the noisy nature of TAP/MS data. Results: We investigated several major TAP/MS data analysis methods for identifying PPIs, and developed an advanced method, which incorporates an improved statistical method to filter out false positives from the negative controls. Our method is named PPIRank that stands for PPI ranking in TAP/MS data. We compared PPIRank with several other existing methods in analyzing two pathway-specific TAP/MS PPI datasets from Drosophila. Conclusion: Experimental results show that PPIRank is more capable than other approaches in terms of identifying known interactions collected in the BioGRID PPI database. Specifically, PPIRank is able to capture more true interactions and simultaneously less false positives in both Insulin and Hippo pathways of Drosophila Melanogaster.
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372. An electrical machine testing system on embedded system.
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Yukun Liu, Yinghui Li, Liwei Guo, and Xiaoyun Sun
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- 2005
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373. Catalytic-assembly of programmable atom equivalents.
- Author
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Dongbao Yao, Yunhan Zhang, Xiang Zhou, Xiaoyun Sun, Xiaoyu Liu, Junxiang Zhou, Wei Jiang, Wenqiang Hua, and Haojun Liang
- Subjects
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COLLOIDAL crystals , *CHEMICAL reactions , *PHASE transitions , *ATOMS , *METASTABLE states , *CATALYTIC reforming - Abstract
Escape from metastable states in self-assembly of colloids is an intractable problem. Unlike the commonly adopted approach of thermal annealing, the recently developed enthalpy-mediated strategy provided a different option to address this dilemma in a dynamically controllable manner at room temperature. However, it required a complex catalytic-assembly DNA strand-displacement circuitry to mediate interaction between multiple components. In this work, we present a simple but effective way to achieve catalytic-assembly of DNA-functionalized colloidal nanoparticles, i.e., programmable atom equivalents, in a far-from-equilibrium system. A removable molecule named "catassembler" that acts as a catalyst was employed to rectify imperfect linkages and help the system escape from metastability without affecting the assembled framework. Notably, catalytic efficiency of the catassembler can be effectively improved by changing the seesaw catassembler in toehold length design or numbers of the repeat units. Leveraging this tractable catalytic-assembly approach, different ordered architectures were easily produced by directly mixing all reactants, as in chemical reactions. By switching bonding identities, solid-solid phase transformations between different colloidal crystals were achieved. This work opens up an avenue for programming colloid assembly in a far-from-equilibrium system. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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374. Computational modeling of Caenorhabditis elegans vulval induction.
- Author
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Xiaoyun Sun and Pengyu Hong
- Subjects
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CAENORHABDITIS elegans , *CAENORHABDITIS , *MORPHOGENESIS , *BIOINFORMATICS - Abstract
Motivation: Caenorhabditis elegans vulval development is a paradigmatic example of animal organogenesis with extensive experimental data. During vulval induction, each of the six multipotent vulval precursor cells (VPCs) commits to one of three fates (1°, 2°, 3°). The precise 1°-2°-3° formation of VPC fates is controlled by a network of intercellular signaling, intracellular signal transduction and transcriptional regulation. The construction of mathematical models for this network will enable hypothesis generation, biological mechanism discovery and system behavior analysis. Results: We have developed a mathematical model based on dynamic Bayesian networks to model the biological network that governs the VPC 1°-2°-3° pattern formation process. Our model has six interconnected subnetworks corresponding to six VPCs. Each VPC subnetwork contains 20 components. The causal relationships among network components are quantitatively encoded in the structure and parameters of the model. Statistical machine learning techniques were developed to automatically learn both the structure and parameters of the model from data collected from literatures. The learned model is capable of simulating vulval induction under 36 different genetic conditions. Our model also contains a few hypothetical causal relationships between network components, and hence can serve as guidance for designing future experiments. The statistical learning nature of our methodology makes it easy to not only handle noise in data but also automatically incorporate new experimental data to refine the model. Contact: hong@cs.brandeis.edu Supplementary information: Supplementary data are available at Bioinformatics online. [ABSTRACT FROM AUTHOR]
- Published
- 2007
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375. Molecular alignment in submicron patterned polymer matrix using nanoimprint lithography.
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Wang, Jian, Jian Wang, Sun, Xiaoyun, Xiaoyun Sun, Chen, Lei, Lei Chen, Zhuang, Lei, Lei Zhuang, and Chou, Stephen Y.
- Subjects
MOLECULAR electronics ,LITHOGRAPHY ,NANOTECHNOLOGY - Abstract
We report a promising approach to align molecules in a polymer film patterned by nanoimprint lithography. We found that molecules and chromophores are spontaneously aligned in the plane of the film during the nanopatterning process. Since the polymer-chromophore (called guest-host) system plays an important role in the field of nonlinear optics and organic optoelectronics, in this letter we present a technique to combine the high-resolution patterning capability of nanoimprint lithography with the ability to control molecule and chromophore orientation. It opens up a way to realize new molecular electronic and optoelectronic devices. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]
- Published
- 2000
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376. The Hippo Signaling Pathway Interactome.
- Author
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Young Kwon, Vinayagam, Arunachalam, Xiaoyun Sun, Dephoure, Noah, Gygi, Steven P., Pengyu Hong, and Perrimon, Norbert
- Subjects
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CELLULAR signal transduction , *APOPTOSIS , *CELL proliferation , *MASS spectrometry , *PROTEIN-protein interactions , *TRANSCRIPTION factors - Abstract
The Hippo pathway controls metazoan organ growth by regulating cell proliferation and apoptosis. Many components have been identified, but our knowledge of the composition and structure of this pathway is still incomplete. Using existing pathway components as baits, we generated by mass spectrometry a high-confidence Drosophila Hippo protein-protein interaction network (Hippo-PPIN) consisting of 153 proteins and 204 interactions. Depletion of 67% of the proteins by RNA interference regulated the transcriptional coactivator Yorkie (Yki) either positively or negatively. We selected for further characterization a new member of the alpha-arrestin family, Leash, and show that it promotes degradation of Yki through the lysosomal pathway. Given the importance of the Hippo pathway in tumor development, the Hippo-PPIN will contribute to our understanding of this network in both normal growth and cancer. [ABSTRACT FROM AUTHOR]
- Published
- 2013
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377. A rapid stability charts analysis method for rock slopes based on Generalized Hoek-Brown criterion.
- Author
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Wei, Yuan, Liyan, Wang, Xing, Zhai, hanhua, Tan, Shu, Peng, Yanyu, Xue, Wei, Wang, Xiaoyun, Sun, and Jiandong, Niu
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ROCK slopes , *ROCK analysis , *FAILED states , *SAFETY factor in engineering , *SLOPE stability - Abstract
Stability charts for slopes remain useful in engineering practice because of their convenience and practicality. This paper presents a new stability chart analysis method based on the Generalized Hoek-Brown (GHB) criterion to rapidly calculate the factor of safety (FOS) of rock slopes. First, critical failure state charts (CFSCs) are produced to represent the relationships among the slope height, unit weight of the rock mass and all the parameters involved in the GHB criterion when the slopes lead to a critical failure state (i.e. FOS = 1.0). Second, based on the CFSCs, the formulas of the FOS derived from mi and dimensionless parameter σcmass/γH are presented for slopes with different slope angles. Thus, the FOS for any slope with a GHB rock mass can be directly determined by taking the GHB parameters (i.e. σc, mi, GSI, and D), the unit weight (γ) and the slope's geometrical parameters (i.e. height H and slope angle β) as inputs. Finally, 25 cases selected from the published literature are used to illustrate the applicability and validity of the proposed method. The results for these cases show good agreement with those obtained with the limit equilibrium method (LEM). [ABSTRACT FROM AUTHOR]
- Published
- 2021
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378. A new criterion for defining the failure of a fractured rock mass slope based on the strength reduction method.
- Author
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Wei, Yuan, Hanhua, Tan, Jiandong, Niu, Shu, Peng, Yanyu, Xue, Wei, Wang, and Xiaoyun, Sun
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LANDSLIDES , *RISK assessment , *ROCKFALL , *PROPERTIES of matter , *MAGNETIC anisotropy - Abstract
In this study, a stability analysis approach for fractured rock mass slopes is proposed by combining the strength reduction method (SRM) with the undirected graph theory (UGT). First, the original shear strength parameters of all the fractures are divided by the same reduction coefficient to generate new shear strength parameters, which are used for numerical simulations of the fractured rock mass slope. Second, the connectivity of the failure fractures is analyzed with a self-developed code, which is developed based on UGT. If no fracture clusters are fully connected from the top of the slope to the toe or free face of the slope, the slope is considered to be stable, and the reduction coefficient is incremented. The above calculation procedures are repeated until there is exactly right a fracture cluster is fully connected (i.e. slope is leaded to critical state). The reduction coefficient that coincides with the critical state is considered as the safety factor of the slope, and the fractured rock mass encompassed by the connected failure fractures is regarded as the unstable part of the slope. Finally, the proposed method is applied to analyze the stability and the potential failure range of a steep slope to verify its validity. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
379. A strength reduction method based on the Generalized Hoek-Brown (GHB) criterion for rock slope stability analysis.
- Author
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Wei, Yuan, Jiaxin, Li, Zonghong, Li, Wei, Wang, and Xiaoyun, Sun
- Subjects
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ROCK slopes , *SLOPE stability , *SAFETY factor in engineering , *EARTH dams - Abstract
The strength reduction method (SRM) combining with the Generalized Hoek-Brown (GHB) criterion has become a widely used means to assess the stability of rock slopes. Therefore, various efforts have been made to establish a standard reduction strategy for strength parameters. This paper presents a new nonlinear SRM based on the GHB criterion, and the core novelty of the proposed method is to provide a reduction strategy with precise physical meaning to find an optimal set of parameters that trigger rock slope failure. To verify the validity of the proposed method, two illustrative examples are analyzed. The results show that the proposed method could lead to a reasonable safety factor, and the critical sliding surface obtained by the proposed method can reflect the tensile crack in the steep slope. Finally, to distinguish the computational results and efficiency among the proposed method and other preexisting reduction methods, other more 8 slopes selected from the literature are used for research objects. The results show that the safety factors resulted from the proposed method are very close to those acquired by the most accurate method available at present (Hammah's method), however, its computational efficiency is comparatively higher than that of Hammah's method. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
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