504 research outputs found

    A COMPARATIVE STUDY ON SOFTWARE PIRACY BETWEEN CHINA AND AMERICA

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    Software piracy in China has been a serious problem for decades. This paper builds on an existing software piracy model and adds a cultural dimension. We aim to study the differences between the U.S. and Chinese college students on their attitude toward software piracy, perceived punishment, subjective norms, perceived behavioral control and piracy intention. Through the data analysis, we aim to find the key factors that influence the piracy intent, to identify the differences between the Chinese and Americans, and to provide insights to fight piracy in China

    Adaptive Optics Confocal Scanning Laser Ophthalmoscope

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    HSF1 overexpression enhances oncolytic effect of replicative adenovirus

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    <p>Abstract</p> <p>Background</p> <p>E1B55kD deleted oncolytic adenovirus was designed to achieve cancer-specific cytotoxicity, but showed limitations in clinical study. To find a method to increase its efficacy, we investigated the correlation between oncolytic effect of such oncolytic adenovirus Adel55 and intracellular heat shock transcription factor 1 (HSF1) activity.</p> <p>Methods</p> <p>In the present study, human breast cancer cell line Bcap37 was stably transfected with constitutively active HSF1 (cHSF1) or HSF1 specific siRNA (HSF1i) to establish increased or decreased HSF1 expression levels. Cytotoxicity of Adel55 was analyzed in these cell lines <it>in vitro </it>and <it>in vivo</it>. Furthermore, Adel55 incorporated with cHSF1 (Adel55-cHSF1) was used to treat various tumor xenografts.</p> <p>Results</p> <p>Adel55 could achieve more efficient oncolysis in cHSF1 transfected Bcap37 cells, both <it>in vitro </it>and <it>in vivo</it>. However, inhibition of HSF1 expression by HSF1i could rescue Bcap37 cell line from oncolysis by Adel55. A time course study of viral replication established a correlation between higher replication of Adel55 and cytolysis or tumor growth inhibition. Then, we constructed Adel55-cHSF1 for tumor gene therapy and demonstrated that it is more potent than Adel55 itself in oncolysis and replication in both Bcap37 and SW620 xenografts.</p> <p>Conclusions</p> <p>cHSF1 enhances the Adel55 cell-killing potential through increasing the viral replication and is a potential therapeutic implication to augment the potential of E1B55kD deleted oncolytic adenovirus by increasing its burst.</p

    Effect of magnetic Fe3O4 nanoparticles with 2-methoxyestradiol on the cell-cycle progression and apoptosis of myelodysplastic syndrome cells

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    This study aims to evaluate the potential benefit of combination therapy of 2-methoxyestradiol (2ME) and magnetic nanoparticles of Fe3O4 (MNPs-Fe3O4) on myelodysplastic syndrome (MDS) SKM-1 cells and its underlying mechanisms. The effect of the unique properties of tetraheptylammonium-capped MNPs-Fe3O4 with 2ME on cytotoxicity was tested by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Cell-cycle distribution and apoptosis were assessed by flow cytometry. The expression of cell-cycle marker protein was measured by Western blotting. Growth inhibition rate of SKM-1 cells treated with the 2ME-loaded MNPs-Fe3O4 was enhanced when compared with 2ME alone. 2ME led to an increase of caspase-3 expression, followed by apoptosis, which was significantly increased when combined with an MNPs-Fe3O4 carrier. Moreover, the copolymer of 2ME with MNPs- Fe3O4 blocked a nearly two-fold increase in SKM-1 cells located in G2/M phase than in 2ME alone, which may be associated with an accompanying increase of p21 as well as a decrease in cyclin B1 and cdc2 expression, but there was no obvious difference between the MNPs-Fe3O4 and control group. These findings suggest that the unique properties of MNPs-Fe3O4 as a carrier for 2ME, a new anticancer agent currently in clinical trials, may be a logical strategy to enhance the therapeutic activity of MDS

    Metastasis-on-a-chip mimicking the progression of kidney cancer in the liver for predicting treatment efficacy.

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    Metastasis is one of the most important factors that lead to poor prognosis in cancer patients, and effective suppression of the growth of primary cancer cells in a metastatic site is paramount in averting cancer progression. However, there is a lack of biomimetic three-dimensional (3D) in vitro models that can closely mimic the continuous growth of metastatic cancer cells in an organ-specific extracellular microenvironment (ECM) for assessing effective therapeutic strategies. Methods: In this metastatic tumor progression model, kidney cancer cells (Caki-1) and hepatocytes (i.e., HepLL cells) were co-cultured at an increasing ratio from 1:9 to 9:1 in a decellularized liver matrix (DLM)/gelatin methacryloyl (GelMA)-based biomimetic liver microtissue in a microfluidic device. Results:Via this model, we successfully demonstrated a linear anti-cancer relationship between the concentration of anti-cancer drug 5-Fluorouracil (5-FU) and the percentage of Caki-1 cells in the co-culture system (R2 = 0.89). Furthermore, the Poly(lactide-co-glycolide) (PLGA)-poly(ethylene glycol) (PEG)-based delivery system showed superior efficacy to free 5-FU in killing Caki-1 cells. Conclusions: In this study, we present a novel 3D metastasis-on-a-chip model mimicking the progression of kidney cancer cells metastasized to the liver for predicting treatment efficacy. Taken together, our study proved that the tumor progression model based on metastasis-on-a-chip with organ-specific ECM would provide a valuable tool for rapidly assessing treatment regimens and developing new chemotherapeutic agents

    Multibeam field emission x-ray system with half-scan reconstruction algorithm: MBFEX system with half-scan reconstruction algorithm

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    Purpose: In this article, the authors propose a multibeam field emission x-ray (MBFEX) system along with a half-scan fan-beam reconstruction algorithm

    Carbon nanotube based X-ray sources: Applications in pre-clinical and medical imaging

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    Field emission offers an alternate method of electron production for Bremsstrahlung based X-ray tubes. Carbon nanotubes (CNTs) serve as very effective field emitters, allowing them to serve as electron sources for X-ray sources, with specific advantages over traditional thermionic tubes. CNT derived X-ray sources can create X-ray pulses of any duration and frequency, gate the X-ray pulse to any source and allow the placement of many sources in close proximity.We have constructed a number of micro-CT systems based on CNT X-ray sources for applications in small animal imaging, specifically focused on the imaging of the heart and lungs. This paper offers a review of the pre-clinical applications of the CNT based micro-CT that we have developed. We also discuss some of the current and potential clinical applications of the CNT X-ray sources

    Compressive Sampling Based Interior Reconstruction for Dynamic Carbon Nanotube Micro-CT

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    In the computed tomography (CT) field, one recent invention is the so-called carbon nanotube (CNT) based field emission x-ray technology. On the other hand, compressive sampling (CS) based interior tomography is a new innovation. Combining the strengths of these two novel subjects, we apply the interior tomography technique to local mouse cardiac imaging using respiration and cardiac gating with a CNT based micro-CT scanner. The major features of our method are: (1) it does not need exact prior knowledge inside an ROI; and (2) two orthogonal scout projections are employed to regularize the reconstruction. Both numerical simulations and in vivo mouse studies are performed to demonstrate the feasibility of our methodology
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