74 research outputs found

    Handheld tumor scanner for breast cancer detection

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    Poster presented at Biomedical Technology Showcase 2006, Philadelphia, PA. Retrieved 18 Aug 2006 from http://www.biomed.drexel.edu/new04/Content/Biomed_Tech_Showcase/Poster_Presentations/Chance.pdf.The amplitude cancellation of in-phase and out of phase of dual source single detector showed remarkable sensitivity to localize small object such as breast tumor with positional accuracy of millimeters. The system design of low frequency, battery operated, mini handheld scanner based the principle of amplitude cancellation is introduced, and performance is evaluated on the phantom simulated the optical properties of tissue and tumor. Some clinical test results are shown

    BIOLOGICAL RESTORATION OF URBAN RIVERS IN CHANGZHOUE -- NORTH RIVER AS CASE STUDY

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    Design and implementation of a multimedia interactive courseware rendering system.

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    It is anticipated that learning and training will become a dominant sector of the global economy within the next decade. The traditional education system is becoming more and more inefficient due to its limitations, such as passive educational environment, limitations of large classes and accessibility. TeleLearning system posses many of the attributes required to solve these problems. TeleLearning system shifts the learners from a passive learning environment to an active learning environment. The learners become the center of the education. Recent advancement in multimedia information processing and the Internet technology allow TeleLearning researchers to simulate real classroom on the Internet, and provide users with access to dynamic multimedia content in a virtual classroom at a time convenient to them. This thesis describes a platform-independent, client/server model for multimedia interactive courseware rendering system. This system helps learners to access course material stored in our multimedia OO database from any access point on the Internet at any time convenient to them

    Molecular Regulation of Bud Regeneration from Callus of Hybrid Sweetgum (<i>Liquidambar styraciflua × Liquidambar formosana</i>)

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    Adventitious bud regeneration is an effective means of rapid propagation of plants, which can be used in the study of plant development and genetic transformation. It can be divided into direct and indirect adventitious bud regeneration. Of the two kinds of adventitious bud regeneration mentioned, indirect adventitious bud regeneration includes callus formation in vitro and organ regeneration. In the process of callus formation, some cells acquire the pluripotency of tissue regeneration, which is the key to regeneration of adventient buds. It is not clear which molecular processes and genetic factors are involved in establishing cellular pluripotency. The object of the study is hybrid sweetgum (Liquidambar styraciflflua × L. formosana). At present, the reproductive efficiency of hybrid sweetgum is low and the reproductive cycle is long. Improving its reproductive efficiency by improving the differentiation speed of callus may be a decent approach. In order to explore the mechanism of pluripotency acquisition during forming hybrid sweetgum callus, we used RNA-seq to perform transcriptomic analysis of the regenerable calli (RC) and non-regenerable (NRC) calli of hybrid sweetgum. A dataset of differentially expressed genes (DEG) was obtained and several genes probably involved in bud formation were analyzed to explain the molecular processes of acquiring and maintaining pluripotency. In this study, a total of 665 significantly expressed DEGs were identified in the RC and NRC of hybrid sweetgum, among which, 585 differentially expressed genes were up-regulated and 80 differentially expressed genes were down-regulated. GO, KEGG analysis and qRT-PCR results showed phenylpropanoid is a key factor regulating the bud regeneration of hybrid sweetgum; WOX1, WOX11, BGLU12 and BGLU13 were also important regulatory factors. These results provide a pivotal reference point for future sweetgum propagation research

    Study of Noise and Vibration Impacts to Buildings Due to Urban Rail Transit and Mitigation Measures

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    The developments in urban rail transit (URT) construction are associated with the benefits of moving people efficiently and the negative impacts of noise and vibrations caused to surroundings. Despite a proliferation of studies conducted throughout the world, very few studies employed the field measurement approach due to various limitations. Using a metropolitan city, Tianjin (China), as an example, field measurement was set up to monitor the indoor vibration and noise spectrum in buildings near urban rapid transit lines to establish a baseline as well as the effectiveness of corresponding mitigation measures, namely wheel-rail polishing and train speed reduction. While our study suggests a maximum 6 dB reduction in indoor vibration, the effectiveness of noise and vibration reduction measures depends on the attenuation of the main frequency corresponding to the secondary radiation noise of the indoor vibration excitation in the building. In our field test, the peaks of the frequency spectrum were found to be 40, 50, 63 and 80 Hz. The secondary radiation noise attenuation and vibration were invariant to the change in frequency spectrum. Mitigation measures such as polishing may cause vibration frequency to peak in non-main frequency spectrums. URT speed reduction will lead to vibration and noise attenuation energy being concentrated at around 50 Hz. Given the presently inconsistent and widely varying industrial and international standards, this study can provide important field measurement data supporting future development in standards, regulation and legislation with respect to URT development, especially in mature townships

    Novel Targeted Anti-Tumor Nanoparticles Developed from Folic Acid-Modified 2-Deoxyglucose

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    The glucose analog, 2-deoxyglucose (2-DG), specifically inhibits glycolysis of cancer cells and interferes with the growth of cancer cells. However, the excellent water solubility of 2-DG makes it difficult to be concentrated in tumor cells. In this study, a targeted nano-pharmacosome was developed with folic acid-modified 2-DG (FA-2-DG) by using amino ethanol as a cleavable linker. FA-2-DG was able to self-assemble, forming nano-particles with diameters of 10&#8315;30 nm. The biological effects were evaluated with cell viability assays and flow cytometry analysis. Compared with a physical mixture of folic acid and 2-DG, FA-2-DG clearly reduced cell viability and resulted in cell cycle arrest. A computational study involving docking simulation suggested that FA-2-DG can dock into the same receptor as folic acid, thus confirming that the structural modification did not affect the targeting performance. The results indicated that the nano-pharmacosome consisting of FA-2-DG can be used for targeting in a nano-drug delivery system

    Exploring the type and strength of nonlinearity in water quality responses to nutrient loading reduction in shallow eutrophic water bodies: Insights from a large number of numerical simulations

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    Reducing the load of nutrients is essential to improve water quality while water quality may not respond to the load reduction in a linear way. Despite nonlinear water quality responses being widely mentioned by studies, there is a lack of comprehensive assessment on the extent and type of nonlinear responses considering the seasonal changes. This study aimed to measure the strength of nonlinearity of theoretically possible water quality responses and explore their potential types in shallow eutrophic water bodies. Hereto, we generated 14,710 numerical water body cases that describe the water quality processes using the Environmental Fluid Dynamics Code (EFDC) and applied eight load reduction scenarios on each water body case. Inflows are simplified from Lake Dianchi. The climate conditions consider three cases: Lake Dianchi, Wissahickon Creek, and Famosa Slough. We then developed a nonlinearity strength indicator to quantify the strength and frequency of nonlinear water quality responses. Based on the quantification of nonlinearity, we clustered all the samples of water quality responses using K-Means, an unsupervised Machine Learning algorithm, to find the potential types of nonlinear water quality responses for TN (total nitrogen), TP (total phosphorus), and Chla (chlorophyll a). Results show linear or near-linear response types account for 90%, 69%, and 20% of TN, TP, and Chla samples respectively. TP and Chla could perform more types of nonlinearity. Representative nonlinear water quality responses include disproportional improvement, peak change (disappear, move forwards or afterward), and seasonal deterioration of TN after load reduction. This study would contribute to the current understanding of nonlinear water quality responses to load reduction and provide a basis to study under which conditions the nonlinear responses may emerge

    Preparation and Characterization of Erythrocyte Membrane-Camouflaged Berberine Hydrochloride-Loaded Gelatin Nanoparticles

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    The discovery of a new pharmacological application of berberine hydrochloride (BH) made it more clinically valuable. However, the further development of BH was hampered by its short half-life and side effects after intravenous injection. To overcome these problems, a novel BH delivery system was developed using natural red blood cell membrane-camouflaged BH-loaded gelatin nanoparticles (RBGPs) to reduce the toxicity associated with injections and achieve sustained release. The size of the RBGPs was 260.3 &plusmn; 4.1 nm, with an obvious core&ndash;shell structure, and the membrane proteins of the RBGPs were mostly retained. The RBGP system showed significant immune-evading capabilities and little cytotoxicity to human embryonic kidney (HEK) 293T cells and LO2 cells. Finally, RBGPs improved the sustained releasing effect of BH significantly. When the cumulative release time reached 120 h, the cumulative release rate of RBGPs was 78.42%. In brief, RBGPs hold the potential to achieve long circulation and sustained-release of BH, avoid side effects caused by high plasma concentration in common injection formulations, and broaden the clinical applications of BH
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