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Search Results: 1 - 10 of 12667 matches for " Aiwei Yao-Borengasser "
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Chondroitin sulfates play a major role in breast cancer metastasis: a role for CSPG4 and CHST11 gene expression in forming surface P-selectin ligands in aggressive breast cancer cells
Craig A Cooney, Fariba Jousheghany, Aiwei Yao-Borengasser, Bounleut Phanavanh, Tina Gomes, Ann Kieber-Emmons, Eric R Siegel, Larry J Suva, Soldano Ferrone, Thomas Kieber-Emmons, Behjatolah Monzavi-Karbassi
Breast Cancer Research , 2011, DOI: 10.1186/bcr2895
Abstract: Quantitative real-time PCR (qRT-PCR) and flow cytometry assays were used to detect the expression of genes involved in the sulfation and presentation of chondroitin in several human breast cancer cell lines. Transient transfection of the human breast cancer cell line MDA-MB-231 with the siRNAs for carbohydrate (chondroitin 4) sulfotransferase-11 (CHST11) and chondroitin sulfate proteoglycan 4 (CSPG4 ) was used to investigate the involvement of these genes in expression of surface P-selectin ligands. The expression of CSPG4 and CHST11 in 15 primary invasive breast cancer clinical specimens was assessed by qRT-PCR. The role of CS-GAGs in metastasis was tested using the 4T1 murine mammary cell line (10 mice per group).The CHST11 gene was highly expressed in aggressive breast cancer cells but significantly less so in less aggressive breast cancer cell lines. A positive correlation was observed between the expression levels of CHST11 and P-selectin binding to cells (P < 0.0001). Blocking the expression of CHST11 with siRNA inhibited CS-A expression and P-selectin binding to MDA-MB-231 cells. The carrier proteoglycan CSPG4 was highly expressed on the aggressive breast cancer cell lines and contributed to the P-selectin binding and CS-A expression. In addition, CSPG4 and CHST11 were over-expressed in tumor-containing clinical tissue specimens compared with normal tissues. Enzymatic removal of tumor-cell surface CS-GAGs significantly inhibited lung colonization of the 4T1 murine mammary cell line (P = 0.0002).Cell surface P-selectin binding depends on CHST11 gene expression. CSPG4 serves as a P-selectin ligand through its CS chain and participates in P-selectin binding to the highly metastatic breast cancer cells. Removal of CS-GAGs greatly reduces metastatic lung colonization by 4T1 cells. The data strongly indicate that CS-GAGs and their biosynthetic pathways are promising targets for the development of anti-metastatic therapies.Tumor-associated glycans play a significant
The Choice of Market Entry Mode: Cross-Border M&A or Greenfield Investment
Aiwei Wang
International Journal of Business and Management , 2009, DOI: 10.5539/ijbm.v4n5p241
Abstract: Multinationals may enter a host market by different modes of foreign direct investment (FDI). Two are widely used: Cross-Border M&A and Greenfield Investment. In practice, M&A transaction has increased dramatically in China over the last several years. This paper examines the choice of FDI modes, and makes a comparison between the two modes from the external and internal impacts. Then get the conclusion that we should choose the right mode according to the different situation about the firms in the international market. The purpose of this paper is going to analyze the two entry modes specifically and helps us better understand the two modes. This article consists of four parts. Part1 is a short introduction to China today. Part II briefly introduces the current status of M&A and Greenfield Investment. Part III compares the two entry modes from their implementations, cost, external and internal sides. At the last part, we get the conclusion and make the suggestions to our investors.
Effect of External Vibration on PZT Impedance Signature
Yaowen Yang,Aiwei Miao
Sensors , 2008, DOI: 10.3390/s8116846
Abstract: Piezoelectric ceramic Lead Zirconate Titanate (PZT) transducers, working on the principle of electromechanical impedance (EMI), are increasingly applied for structural health monitoring (SHM) in aerospace, civil and mechanical engineering. The PZT transducers are usually surface bonded to or embedded in a structure and subjected to actuation so as to interrogate the structure at the desired frequency range. The interrogation results in the electromechanical admittance (inverse of EMI) signatures which can be used to estimate the structural health or integrity according to the changes of the signatures. In the existing EMI method, the monitored structure is only excited by the PZT transducers for the interrogating of EMI signature, while the vibration of the structure caused by the external excitations other than the PZT actuation is not considered. However, many structures work under vibrations in practice. To monitor such structures, issues related to the effects of vibration on the EMI signature need to be addressed because these effects may lead to misinterpretation of the structural health. This paper develops an EMI model for beam structures, which takes into account the effect of beam vibration caused by the external excitations. An experimental study is carried out to verify the theoretical model. A lab size specimen with different external excitations is tested and the effect of vibration on EMI signature is discussed.
Investigation on Photovoltaic Performance based on Matchstick-Like Cu2S–In2S3Heterostructure Nanocrystals and Polymer
Tang Aiwei,Teng Feng,Wang Yan,Hou Yanbing
Nanoscale Research Letters , 2008,
Abstract: In this paper, we synthesized a novel type II cuprous sulfide (Cu2S)–indium sulfide (In2S3) heterostructure nanocrystals with matchstick-like morphology in pure dodecanethiol. The photovoltaic properties of the heterostructure nanocrystals were investigated based on the blends of the nanocrystals and poly(2-methoxy-5-(2′-ethylhexoxy)-p-phenylenevinylene) (MEH-PPV). In comparison with the photovoltaic properties of the blends of Cu2S or In2S3nanocrystals alone and MEH-PPV, the power conversion efficiency of the hybrid device based on blend of Cu2S–In2S3and MEH-PPV is enhanced by ~3–5 times. This improvement is consistent with the improved exciton dissociation or separation and better charge transport abilities in type II heterostructure nanocrystals.
Effect of ZnCdTe-Alloyed Nanocrystals on Polymer–Fullerene Bulk Heterojunction Solar Cells
Wang Yan,Hou Yanbing,Tang Aiwei,Feng Zhihui
Nanoscale Research Letters , 2009,
Abstract: The photovoltaic properties of solar cell based on the blends of poly[2-methoxy-5-(2-ethylhexoxy-1,4-phenylenevinylene) (MEH-PPV), fullerene (C60), and ZnCdTe-alloyed nanocrystals were investigated. Comparing the spectral response of photocurrent of the MEH-PPV:C60(+ZnCdTe) nanocomposite device with that of the devices based on MEH-PPV:C60and pristine MEH-PPV, one can find that the nanocomposite device exhibits an enhanced photocurrent. In comparing the composite devices with different ZnCdTe:[MEH-PPV + C60] weight ratios of 10 wt% (D1–1), 20 wt% (D1–2), 40 wt% (D1–3), and 70 wt% (D1–4), it was found that the device D1–3exhibits the best performance. The power conversion efficiency (η) is improved doubly compared with that of the MEH-PPV:C60device.
Polymersomes and Wormlike Micelles Made Fluorescent by Direct Modifications of Block Copolymer Amphiphiles
Karthikan Rajagopal,David A. Christian,Takamasa Harada,Aiwei Tian,Dennis E. Discher
International Journal of Polymer Science , 2010, DOI: 10.1155/2010/379286
Abstract: Wormlike micelles and vesicles prepared from diblock copolymers are attracting great interest for a number of technological applications. Although transmission electron microscopy has remained as the method of choice for assessing the morphologies, fluorescence microscopy has a number of advantages. We show here that when commercially available fluorophores are covalently attached to diblock copolymers, a number of their physicochemical characteristics can be investigated. This method becomes particularly useful for visualizing phase separation within polymer assemblies and assessing the dynamics of wormlike micelles in real time. Near-IR fluorophores can be covalently conjugated to polymers and this opens the possibility for deep-tissue fluorescence imaging of polymer assemblies in drug delivery applications. 1. Introduction In aqueous solution, amphiphilic diblock copolymers can spontaneously self-assemble to form supramolecular morphologies such as spherical and worm-like micelles and vesicles (polymersomes) [1–3]. Due to their unique physico-chemical characteristics these polymeric assemblies have shown potential for various applications such as drug delivery. Wormlike micelles (“worms”) increase the delivered dose of water-insoluble drugs such as Taxol [4, 5], and vesicles (polymersomes) can be used for the encapsulation and delivery of both water-insoluble (Taxol) and water-soluble therapeutics that range from drugs to proteins [6] to siRNA [7]. An understanding of morphologies from amphiphilic diblock copolymers in dilute solution as well as their characteristics would facilitate the generation of even more robust and useful supra-molecular materials. Seminal experiments of Eisenberg and Bates helped to show that classic ideas of surfactant-based morphologies also apply to block copolymers upon varying the relative sizes of the two dissimilar blocks [8, 9]. While such studies used TEM to visualize frozen nano-morphologies, we have emphasized and exploited fluorescence imaging, including the use of dyes covalently conjugated to block copolymers as described here. Fluorescence microscopy helps to clarify many of the unique physical characteristics of polymer assemblies, including the diversity in sizes, shapes, flexibilities and lateral segregation. Fluoroscence microscopy is widely used in cell biology and biophysics for understanding the structure and function of molecules within cells and organelles [10–12]. Although one cannot infer structural information below the diffraction limit, this method nevertheless enables the visualization of spatial
Capacity Worth of Energy Storage System in Renewable Power Generation Plant  [PDF]
Jinbin Li, Yao Yao
Engineering (ENG) , 2013, DOI: 10.4236/eng.2013.59B001
Abstract: With the advance in renewable generation technologies, the cost of renewable energy becomes increasingly competitive when compared to fossil fuel-based generation resources. It is economically beneficial to integrate large amounts of renewable capacity in power systems. Unlike traditional generation facilities, however, using renewable resources for generation presents technical challenges in producing continuous power. In this report, an Energy Storage System (ESS) is integrated to smooth the variations in renewable power production and ensure the output power more controllable. Since it requires capital investment for the storage devices, it is important to obtain reasonable estimate of the storage capacities. This project is therefore formulated as an optimization problem in determining the two dominating factors of the capital cost for the ESS: the power capacity and the energy capacity. The objective is to make the renewable power more reliable and simultaneously maximize the economic benefits that can be obtained from the scheme. To make the results more convincing, analyses in this report start with wind generation, for wind has greater variability and unpredictability than other renewable sources. Selection of ESS type is narrowed down to battery energy storage system (BESS) in the scheme. However, the methods presented here are suitable for any type of energy storage methods and are also useful for intermittent renewable energy resources other than wind.
The Senile Brucellosis Spondylitis Clinical Diagnosis and Treatment on as Evaluation Were Retrospectively Analyzed  [PDF]
Yao Yao, Xinming Yang
Surgical Science (SS) , 2018, DOI: 10.4236/ss.2018.98032
Abstract: Objective: To explore senile brucellosis spondylitis clinical features and diagnostic criteria, in order to improve the diagnosis rate and evaluate the clinical effects of treatment strategies. Methods: From January 2002 to August 2015, 62 patients with Brucella-associated spondylitis were treated with comprehensive diagnosis based on epidemiological history, clinical manifestations, imaging findings, laboratory tests, and local biopsy. The positive rate of red plate agglutination test (RBPT) was 45.1%, the positive rate of serum tube agglutination test (SAT) was 51.6%, and the positive rate of brucellosis anti-human immunoglobulin test (Coomb’s) was 100%. All patients underwent X-ray, CT and MRI examinations. The positive rate of blood culture in pathogenic examination was 16.1%, and the positive rate of bone marrow culture was 38.5%. The positive rate of inflammatory granuloma or abscess in the lesion sampling culture was 73.6%. All patients underwent standardized drug therapy and hyperbaric oxygen adjuvant therapy. Among them, 38 patients with neurological impairment were treated with one-stage debridement and posterior pedicle screw fixation on the basis of drug therapy. The paraspinal abscess and the diseased in-tervertebral space tissue were taken for pathological examination during the operation. One week, two weeks, one month, three months, six months and 12 months after treatment, the patients were evaluated and followed up at the monitoring sites. The evaluation indicators were pain scores, activity of daily living (ADL), imaging findings, and laboratory tests. The SPSS15.0 statistical package was used for analysis. Results: All patients were confirmed by the above-mentioned comprehensive examination after admission. 24 patients (38.71%) were treated with standard drug therapy (group A), no adverse drug reactions and abnormal liver and kidney function; the remaining 38 patients (61.29%) were combined with varying degrees of neurological impairment, and surgical treatment was performed after 2 to 4 weeks of drug therapy without improvement (group B). The pain scores showed that there was a statistically significant difference between the two groups at the same time point (P < 0.05). The B group was superior to the A group in both treatment time and pain relief. The blind test evaluation of imaging observation showed that in group B, except for the slow repair of the lesion area, the spine was stable without abscess, sequestrum and inflammatory granulomas, and the score area was stable at 4 -
Maternal Obesity during Gestation Impairs Fatty Acid Oxidation and Mitochondrial SIRT3 Expression in Rat Offspring at Weaning
Sarah J. Borengasser, Franchesca Lau, Ping Kang, Michael L. Blackburn, Martin J. J. Ronis, Thomas M. Badger, Kartik Shankar
PLOS ONE , 2011, DOI: 10.1371/journal.pone.0024068
Abstract: In utero exposure to maternal obesity increases the offspring's risk of obesity in later life. We have also previously reported that offspring of obese rat dams develop hepatic steatosis, mild hyperinsulinemia, and a lipogenic gene signature in the liver at postnatal day (PND)21. In the current study, we examined systemic and hepatic adaptations in male Sprague-Dawley offspring from lean and obese dams at PND21. Indirect calorimetry revealed decreases in energy expenditure (p<0.001) and increases in RER values (p<0.001), which were further exacerbated by high fat diet (45% kcals from fat) consumption indicating an impaired ability to utilize fatty acids in offspring of obese dams as analyzed by PRCF. Mitochondrial function is known to be associated with fatty acid oxidation (FAO) in the liver. Several markers of hepatic mitochondrial function were reduced in offspring of obese dams. These included SIRT3 mRNA (p = 0.012) and mitochondrial protein content (p = 0.002), electron transport chain complexes (II, III, and ATPase), and fasting PGC-1α mRNA expression (p<0.001). Moreover, hepatic LCAD, a SIRT3 target, was not only reduced 2-fold (p<0.001) but was also hyperacetylated in offspring of obese dams (p<0.005) suggesting decreased hepatic FAO. In conclusion, exposure to maternal obesity contributes to early perturbations in whole body and liver energy metabolism. Mitochondrial dysfunction may be an underlying event that reduces hepatic fatty acid oxidation and precedes the development of detrimental obesity associated co-morbidities such as insulin resistance and NAFLD.
High Fat Diet and In Utero Exposure to Maternal Obesity Disrupts Circadian Rhythm and Leads to Metabolic Programming of Liver in Rat Offspring
Sarah J. Borengasser, Ping Kang, Jennifer Faske, Horacio Gomez-Acevedo, Michael L. Blackburn, Thomas M. Badger, Kartik Shankar
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0084209
Abstract: The risk of obesity in adulthood is subject to programming beginning at conception. In animal models, exposure to maternal obesity and high fat diets influences the risk of obesity in the offspring. Among other long-term changes, offspring from obese rats develop hyperinsulinemia, hepatic steatosis, and lipogenic gene expression in the liver at weaning. However, the precise underlying mechanisms leading to metabolic dysregulation in the offspring remains unclear. Using a rat model of overfeeding-induced obesity, we previously demonstrated that exposure to maternal obesity from pre-conception to birth, is sufficient to program increased obesity risk in the offspring. Offspring of obese rat dams gain greater body weight and fat mass when fed high fat diet (HFD) as compared to lean dam. Since, disruptions of diurnal circadian rhythm are known to detrimentally impact metabolically active tissues such as liver, we examined the hypothesis that maternal obesity leads to perturbations of core clock components and thus energy metabolism in offspring liver. Offspring from lean and obese dams were examined at post-natal day 35, following a short (2 wk) HFD challenge. Hepatic mRNA expression of circadian (CLOCK, BMAL1, REV-ERBα, CRY, PER) and metabolic (PPARα, SIRT1) genes were strongly suppressed in offspring exposed to both maternal obesity and HFD. Using a mathematical model, we identified two distinct biological mechanisms that modulate PPARα mRNA expression: i) decreased mRNA synthesis rates; and ii) increased non-specific mRNA degradation rate. Moreover, our findings demonstrate that changes in PPARα transcription were associated with epigenomic alterations in H3K4me3 and H3K27me3 histone marks near the PPARα transcription start site. Our findings indicated that offspring from obese rat dams have detrimental alternations to circadian machinery that may contribute to impaired liver metabolism in response to HFD, specifically via reduced PPARα expression prior to obesity development.
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