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Sample records for microbubble destruction mediated

  1. Ultrasound Mediated Microbubbles Destruction Augmented Sonolysis: An In Vitro and In Vivo Study.

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    Cui, Hai; Zhu, Qiong; Gao, Yunhua; Xia, Hongmei; Tan, Kaibin; He, Ying; Liu, Zheng; Xu, Yali

    2017-01-01

    This study was aimed at exploring ultrasound mediated microbubbles destruction (UMMD) assisted sonolysis in both the in vitro and in vivo clots. Therapeutic ultrasound (TUS) and lipid microbubbles (MBs) were used in whole blood clots and divided into the control, TUS group, and TUS + MB group. Thrombolytic rates and microscopy were performed. Color Doppler flow imaging (CDFI) and angiography were performed to evaluate the recanalization rates and flow scores in femoral arterial thrombus (FAT) in rabbits. FAT were dyed with H&E. The average thrombolytic ratios of TUS + MB group were significantly higher than those of TUS group and the control group (both P cavitation via UMMD.

  2. Ultrasound Mediated Microbubbles Destruction Augmented Sonolysis: An In Vitro and In Vivo Study

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    Hai Cui

    2017-01-01

    Full Text Available Objective. This study was aimed at exploring ultrasound mediated microbubbles destruction (UMMD assisted sonolysis in both the in vitro and in vivo clots. Methods. Therapeutic ultrasound (TUS and lipid microbubbles (MBs were used in whole blood clots and divided into the control, TUS group, and TUS + MB group. Thrombolytic rates and microscopy were performed. Color Doppler flow imaging (CDFI and angiography were performed to evaluate the recanalization rates and flow scores in femoral arterial thrombus (FAT in rabbits. FAT were dyed with H&E. Results. The average thrombolytic ratios of TUS + MB group were significantly higher than those of TUS group and the control group (both P<0.05. Clots had different pathological changes. Recanalization rates and flow scores in TUS + MB group were significantly higher than the control and TUS group. Flow scores and recanalization ratios were grade 0 in 0% of the control group, grade I in 25% of TUS group, and grade II or higher in 87.5% of TUS + MB group after 30 min sonolysis. Conclusions. Both the in vitro and in vivo sonolysis can be significantly augmented by the introduction of MBs without thrombolytic agents, which might be induced by the enhanced cavitation via UMMD.

  3. Ultrasonic destruction of albumin microbubbles enhances gene transfection and expression in cardiac myocytes.

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    Wang, Guo-zhong; Liu, Jing-hua; Lü, Shu-zheng; Lü, Yun; Guo, Cheng-jun; Zhao, Dong-hui; Fang, Dong-ping; He, Dong-fang; Zhou, Yuan; Ge, Chang-jiang

    2011-05-01

    It has been proven that ultrasonic destruction of microbubbles can enhance gene transfection efficiency into the noncardiac cells, but there are few reports about cardiac myocytes. Moreover, the exact mechanisms are not yet clear; whether the characteristic of microbubbles can affect the gene transfection efficiency or not is still controversial. This study was designed to investigate whether the ultrasound destruction of gene-loaded microbubbles could enhance the plasmids carried reporter gene transfection in primary cultured myocardial cell, and evaluate the effects of microbubbles characteristics on the transgene expression in cardiac myocytes. The β-galactosidase plasmids attached to the two types of microbubbles, air-contained sonicated dextrose albumin (ASDA) and perfluoropropane-exposed sonicated dextrose albumin (PESDA) were prepared. The gene transfection into cardiac myocytes was performed in vitro by naked plasmids, ultrasound exposure, ultrasonic destruction of gene-loaded microbubbles and calcium phosphate precipitation, and then the gene expression and cell viability were analyzed. The ultrasonic destruction of gene-loaded microbubbles enhanced gene expression in cardiac myocytes compared with naked plasmid transfection ((51.95 ± 2.41) U/g or (29.28 ± 3.65) U/g vs. (0.84 ± 0.21) U/g, P ASDA ((51.95 ± 2.41) U/g vs. (29.28 ± 3.65) U/g, P < 0.05). Ultrasonic destruction of microbubbles during calcium phosphate precipitation gene transfection enhanced β-galactosidase activity nearly 8-fold compared with calcium phosphate precipitation gene transfection alone ((111.35 ± 11.21) U/g protein vs. (14.13 ± 2.58) U/g protein, P < 0.01). Even 6 hours after calcium phosphate precipitation gene transfection, ultrasound-mediated microbubbles destruction resulted in more intense gene expression ((35.63 ± 7.65) U/g vs. (14.13 ± 2.58) U/g, P < 0.05). Ultrasonic destruction of microbubbles might be a promising method for the delivery of non-viral DNA into

  4. Unilateral Opening of Rat Blood-Brain Barrier Assisted by Diagnostic Ultrasound Targeted Microbubbles Destruction.

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    Xu, Yali; Cui, Hai; Zhu, Qiong; Hua, Xing; Xia, Hongmei; Tan, Kaibin; Gao, Yunhua; Zhao, Jing; Liu, Zheng

    2016-01-01

    Objective. Blood-brain barrier (BBB) is a key obstacle that prevents the medication from blood to the brain. Microbubble-enhanced cavitation by focused ultrasound can open the BBB and proves to be valuable in the brain drug delivery. The study aimed to explore the feasibility, efficacy, and safety of unilateral opening of BBB using diagnostic ultrasound targeted microbubbles destruction in rats. Methods. A transtemporal bone irradiation of diagnostic ultrasound and intravenous injection of lipid-coated microbubbles were performed at unilateral hemisphere. Pathological changes were monitored. Evans Blue extravasation grades, extraction from brain tissue, and fluorescence optical density were quantified. Lanthanum nitrate was traced by transmission electron microscopy. Results. After diagnostic ultrasound mediated microbubbles destruction, Evans Blue extravasation and fluorescence integrated optical density were significantly higher in the irradiated hemisphere than the contralateral side (all p ultrasound-exposed hemisphere (4 ± 1, grade 2) while being invisible in the control side. Lanthanum nitrate tracers leaked through interendothelial cleft and spread to the nerve fiber existed in the irradiation side. Conclusions. Transtemporal bone irradiation under DUS mediated microbubble destruction provides us with a more accessible, safer, and higher selective BBB opening approach in rats, which is advantageous in brain targeted drugs delivery.

  5. Unilateral Opening of Rat Blood-Brain Barrier Assisted by Diagnostic Ultrasound Targeted Microbubbles Destruction

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    Yali Xu

    2016-01-01

    Full Text Available Objective. Blood-brain barrier (BBB is a key obstacle that prevents the medication from blood to the brain. Microbubble-enhanced cavitation by focused ultrasound can open the BBB and proves to be valuable in the brain drug delivery. The study aimed to explore the feasibility, efficacy, and safety of unilateral opening of BBB using diagnostic ultrasound targeted microbubbles destruction in rats. Methods. A transtemporal bone irradiation of diagnostic ultrasound and intravenous injection of lipid-coated microbubbles were performed at unilateral hemisphere. Pathological changes were monitored. Evans Blue extravasation grades, extraction from brain tissue, and fluorescence optical density were quantified. Lanthanum nitrate was traced by transmission electron microscopy. Results. After diagnostic ultrasound mediated microbubbles destruction, Evans Blue extravasation and fluorescence integrated optical density were significantly higher in the irradiated hemisphere than the contralateral side (all p<0.01. Erythrocytes extravasations were demonstrated in the ultrasound-exposed hemisphere (4±1, grade 2 while being invisible in the control side. Lanthanum nitrate tracers leaked through interendothelial cleft and spread to the nerve fiber existed in the irradiation side. Conclusions. Transtemporal bone irradiation under DUS mediated microbubble destruction provides us with a more accessible, safer, and higher selective BBB opening approach in rats, which is advantageous in brain targeted drugs delivery.

  6. Introduction to the ultrasound targeted microbubble destruction technique.

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    Walton, Chad B; Anderson, Cynthia D; Boulay, Rachel; Shohet, Ralph V

    2011-06-12

    In UTMD, bioactive molecules, such as negatively charged plasmid DNA vectors encoding a gene of interest, are added to the cationic shells of lipid microbubble contrast agents. In mice these vector-carrying microbubbles can be administered intravenously or directly to the left ventricle of the heart. In larger animals they can also be infused through an intracoronary catheter. The subsequent delivery from the circulation to a target organ occurs by acoustic cavitation at a resonant frequency of the microbubbles. It seems likely that the mechanical energy generated by the microbubble destruction results in transient pore formation in or between the endothelial cells of the microvasculature of the targeted region. As a result of this sonoporation effect, the transfection efficiency into and across the endothelial cells is enhanced, and transgene-encoding vectors are deposited into the surrounding tissue. Plasmid DNA remaining in the circulation is rapidly degraded by nucleases in the blood, which further reduces the likelihood of delivery to non-sonicated tissues and leads to highly specific target-organ transfection.

  7. Enhanced delivery of PEAL nanoparticles with ultrasound targeted microbubble destruction mediated siRNA transfection in human MCF-7/S and MCF-7/ADR cells in vitro

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    Teng Y

    2015-08-01

    Full Text Available Yanwei Teng,1,2,* Min Bai,3,* Ying Sun,2 Qi Wang,1,2 Fan Li,3 Jinfang Xing,3 Lianfang Du,3 Tao Gong,1 Yourong Duan2 1Key Laboratory of Drug Targeting and Novel Drug Delivery Systems, Ministry of Education, West China School of Pharmacy, Sichuan University, Chengdu, Sichuan, People’s Republic of China; 2State Key Laboratory of Oncogenes and Related Genes, Shanghai Cancer Institute, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, People’s Republic of China; 3Department of Ultrasound, Shanghai First People’s Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, People’s Republic of China *These authors contributed equally to this work Abstract: The gene knockdown activity of small interfering RNA (siRNA has led to their use as potential therapeutics for a variety of diseases. However, successful gene therapy requires safe and efficient delivery systems. In this study, we choose mPEG-PLGA-PLL nanoparticles (PEAL NPs with ultrasound targeted microbubble destruction (UTMD to efficiently deliver siRNA into cells. An emulsification-solvent evaporation method was used to prepare siRNA-loaded PEAL NPs. The NPs possessed an average size of 132.6±10.3 nm (n=5, with a uniform spherical shape, and had an encapsulation efficiency (EE of more than 98%. As demonstrated by MTT assay, neither PEAL NPs nor siRNA-loaded PEAL NPs showed cytotoxicity even at high concentrations. The results of cellular uptake showed, with the assistance of UTMD, the siRNA-loaded PEAL NPs can be effectively internalized and can subsequently release siRNA in cells. Taken together, PEAL NPs with UTMD may be highly promising for siRNA delivery, making it possible to fully exploit the potential of siRNA-based therapeutics. Keywords: gene delivery, mPEG-PLGA-PLL, UTMD, emulsification-solvent evaporation method, orthogonal design

  8. Ultrasound-targeted microbubble destruction improves the low density lipoprotein receptor gene expression in HepG2 cells

    International Nuclear Information System (INIS)

    Guo Dongping; Li Xiaoyu; Sun, Ping; Tang Yibo; Chen Xiuying; Chen Qi; Fan Leming; Zang Bin; Shao Lizheng; Li Xiaorong

    2006-01-01

    Ultrasound-targeted microbubble destruction had been employed in gene delivery and promised great potential. Liver has unique features that make it attractive for gene therapy. However, it poses formidable obstacles to hepatocyte-specific gene delivery. This study was designed to test the efficiency of therapeutic gene transfer and expression mediated by ultrasound/microbubble strategy in HepG 2 cell line. Air-filled albumin microbubbles were prepared and mixed with plasmid DNA encoding low density lipoprotein receptor (LDLR) and green fluorescent protein. The mixture of the DNA and microbubbles was administer to cultured HepG 2 cells under variable ultrasound conditions. Transfection rate of the transferred gene and cell viability were assessed by FACS analysis, confocal laser scanning microscopy, Western blot analysis and Trypan blue staining. The result demonstrated that microbubbles with ultrasound irradiation can significantly elevate exogenous LDLR gene expression and the expressed LDLRs were functional and active to uptake their ligands. We conclude that ultrasound-targeted microbubble destruction has the potential to promote safe and efficient LDLR gene transfer into hepatocytes. With further refinement, it may represent an effective nonviral avenue of gene therapy for liver-involved genetic diseases

  9. Effects of the microbubble shell physicochemical properties on ultrasound-mediated drug delivery to the brain.

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    Wu, Shih-Ying; Chen, Cherry C; Tung, Yao-Sheng; Olumolade, Oluyemi O; Konofagou, Elisa E

    2015-08-28

    Lipid-shelled microbubbles have been used in ultrasound-mediated drug delivery. The physicochemical properties of the microbubble shell could affect the delivery efficiency since they determine the microbubble mechanical properties, circulation persistence, and dissolution behavior during cavitation. Therefore, the aim of this study was to investigate the shell effects on drug delivery efficiency in the brain via blood-brain barrier (BBB) opening in vivo using monodisperse microbubbles with different phospholipid shell components. The physicochemical properties of the monolayer were varied by using phospholipids with different hydrophobic chain lengths (C16, C18, and C24). The dependence on the molecular size and acoustic energy (both pressure and pulse length) were investigated. Our results showed that a relatively small increase in the microbubble shell rigidity resulted in a significant increase in the delivery of 40-kDa dextran, especially at higher pressures. Smaller (3kDa) dextran did not show significant difference in the delivery amount, suggesting that the observed shell effect was molecular size-dependent. In studying the impact of acoustic energy on the shell effects, it was found that they occurred most significantly at pressures causing microbubble destruction (450kPa and 600kPa); by increasing the pulse length to deliver the 40-kDa dextran, the difference between C16 and C18 disappeared while C24 still achieved the highest delivery efficiency. These indicated that the acoustic energy could be used to modulate the shell effects. The acoustic cavitation emission revealed the physical mechanisms associated with different shells. Overall, lipid-shelled microbubbles with long hydrophobic chain length could achieve high delivery efficiency for larger molecules especially with high acoustic energy. Our study, for the first time, offered evidence directly linking the microbubble monolayer shell with their efficacy for drug delivery in vivo. Copyright © 2015

  10. Ultrasound Targeted Microbubble Destruction Stimulates Cellular Endocytosis in Facilitation of Adeno-Associated Virus Delivery

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    Lian-Fang Du

    2013-05-01

    Full Text Available The generally accepted mechanism for ultrasound targeted microbubble destruction (UTMD to enhance drug and gene delivery is through sonoporation. However, passive uptake of adeno-associated virus (AAV into cells following sonoporation does not adequately explain observations of enhanced transduction by UTMD. This study investigated alternative mechanisms of UTMD enhancement in AAV delivery. UTMD significantly enhanced transduction efficiency of AAV in a dose-dependent manner. UTMD stimulated a persistent uptake of AAV into the cytoplasm and nucleus. This phenomenon occurred over several hours, suggesting that some viral particles are endocytosed by cells rather than exclusively passing through pores created by sonoporation. Additionally, UTMD enhanced clathrin expression and accumulation at the plasma membrane suggesting greater clathrin-mediated endocytosis following UTMD. Transmission electron microscopy (TEM revealed that UTMD stimulated formation of clathrin-coated pits (CPs and uncoated pits (nCPs. Furthermore, inhibition of clathrin-mediated endocytosis partially blocked the enhancement of AAV uptake following UTMD. The results of this study implicate endocytosis as a mechanism that contributes to UTMD-enhanced AAV delivery.

  11. Ultrasound-targeted microbubble destruction enhances naked plasmid DNA transfection in rabbit Achilles tendons in vivo.

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    Qiu, L; Zhang, L; Wang, L; Jiang, Y; Luo, Y; Peng, Y; Lin, L

    2012-07-01

    The study was to investigate the probability of increasing the transfection of the gene in tendons by ultrasound-targeted microbubble destruction (UTMD), and to search for the most suitable transfection conditions. A mixture of microbubbles and enhanced green fluorescent protein (EGFP) plasmids was injected into rabbit Achilles tendons by different administration routes and the tendons were ultrasound pulse by different ultrasonic conditions in order to determine the most appropriate conditions. Then, the rabbits were divided into four groups: (1) ultrasound + microbubbles + plasmid; (2) ultrasound+ plasmid; (3) microbubble + plasmid; (4) plasmid only. EGFP expression in the tendons and other tissues, and the damage to tendon and paratenon were all observed. The results showed that EGFP expression in the tendon was higher by ultrasound pulse with 2 W cm(-2) of output intensity and a 20% duty cycle for 10 min. Local injection was determined to be the better administration route. Among the four groups, EGFP expression in Group 1 was higher than that in other groups. EGFP expression was highest on seventh day, then it gradually decrease over time, and lasted more than 56 days. EGFP expression was not found in other tissues. There was no obvious injury caused by UTMD. Under suitable conditions, it is feasible to use UTMD as a safe and effective gene transfection therapy for tendon injuries.

  12. Microbubble-Mediated Ultrasound Enhances the Lethal Effect of Gentamicin on Planktonic Escherichia coli

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    Han-Xiao Zhu

    2014-01-01

    Full Text Available Previous research has found that low-intensity ultrasound enhanced the lethal effect of gentamicin on planktonic E. coli. We aimed to further investigate whether microbubble-mediated low-intensity ultrasound could further enhance the antimicrobial efficacy of gentamicin. The planktonic E. coli (ATCC 25922 was distributed to four different interventions: control (GCON, microbubble only (GMB, ultrasound only (GUS, and microbubble-mediated ultrasound (GMUS. Ultrasound was applied with 100 mW/cm2 (average intensity and 46.5 KHz, which presented no bactericidal activity. After 12 h, plate counting was used to estimate the number of bacteria, and bacterial micromorphology was observed with transmission electron microscope. The results showed that the viable counts of E. coli in GMUS were decreased by 1.01 to 1.42 log10 CFU/mL compared with GUS (P<0.01. The minimal inhibitory concentration (MIC of gentamicin against E. coli was 1 μg/mL in the GMUS and GUS groups, lower than that in the GCON and GMB groups (2 μg/mL. Transmission electron microscopy (TEM images exhibited more destruction and higher thickness of bacterial cell membranes in the GMUS than those in other groups. The reason might be the increased permeability of cell membranes for gentamicin caused by acoustic cavitation.

  13. Myocardial regeneration in adriamycin cardiomyopathy by nuclear expression of GLP1 using ultrasound targeted microbubble destruction

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    Chen, Shuyuan [Baylor Research Institute, Baylor University Medical Center, 3812 Elm Street, Dallas, TX (United States); Chen, Jiaxi [The University of Texas Southwestern Medical Center at Dallas, Medical School, 5235 Harry Hine Blvd., Dallas, TX (United States); Huang, Pintong [Department of Ultrasonography, The 2nd Affiliated Hospital of Zhejiang University College of Medicine, Hangzhou, Zhejiang Province (China); Meng, Xing-Li; Clayton, Sandra; Shen, Jin-Song [Baylor Research Institute, Baylor University Medical Center, 3812 Elm Street, Dallas, TX (United States); Grayburn, Paul A., E-mail: paulgr@baylorhealth.edu [Baylor Research Institute, Baylor University Medical Center, 3812 Elm Street, Dallas, TX (United States); Department of Internal Medicine, Division of Cardiology, Baylor Heart and Vascular Institute, Baylor University Medical Center, 621 N. Hall St, Suite H030, Dallas, TX (United States)

    2015-03-20

    Recently GLP-1 was found to have cardioprotective effects independent of those attributable to tight glycemic control. Methods and results: We employed ultrasound targeted microbubble destruction (UTMD) to deliver piggybac transposon plasmids encoding the GLP-1 gene with a nuclear localizing signal to rat hearts with adriamycin cardiomyopathy. After a single UTMD treatment, overexpression of transgenic GLP-1 was found in nuclei of rat heart cells with evidence that transfected cardiac cells had undergone proliferation. UTMD-GLP-1 gene therapy restored LV mass, fractional shortening index, and LV posterior wall diameter to nearly normal. Nuclear overexpression of GLP-1 by inducing phosphorylation of FoxO1-S256 and translocation of FoxO1 from the nucleus to the cytoplasm significantly inactivated FoxO1 and activated the expression of cyclin D1 in nuclei of cardiac muscle cells. Reversal of adriamycin cardiomyopathy appeared to be mediated by dedifferentiation and proliferation of nuclear FoxO1-positive cardiac muscle cells with evidence of embryonic stem cell markers (OCT4, Nanog, SOX2 and c-kit), cardiac early differentiation markers (NKX2.5 and ISL-1) and cellular proliferation markers (BrdU and PHH3) after UTMD with GLP-1 gene therapy. Conclusions: Intranuclear myocardial delivery of the GLP-1gene can reverse established adriamycin cardiomyopathy by stimulating myocardial regeneration. - Highlights: • The activation of nuclear FoxO1 in cardiac muscle cells associated with adriamycin cardiomyopathy. • Myocardial nuclear GLP-1 stimulates myocardial regeneration and reverses adriamycin cardiomyopathy. • The process of myocardial regeneration associated with dedifferentiation and proliferation.

  14. Myocardial regeneration in adriamycin cardiomyopathy by nuclear expression of GLP1 using ultrasound targeted microbubble destruction

    International Nuclear Information System (INIS)

    Chen, Shuyuan; Chen, Jiaxi; Huang, Pintong; Meng, Xing-Li; Clayton, Sandra; Shen, Jin-Song; Grayburn, Paul A.

    2015-01-01

    Recently GLP-1 was found to have cardioprotective effects independent of those attributable to tight glycemic control. Methods and results: We employed ultrasound targeted microbubble destruction (UTMD) to deliver piggybac transposon plasmids encoding the GLP-1 gene with a nuclear localizing signal to rat hearts with adriamycin cardiomyopathy. After a single UTMD treatment, overexpression of transgenic GLP-1 was found in nuclei of rat heart cells with evidence that transfected cardiac cells had undergone proliferation. UTMD-GLP-1 gene therapy restored LV mass, fractional shortening index, and LV posterior wall diameter to nearly normal. Nuclear overexpression of GLP-1 by inducing phosphorylation of FoxO1-S256 and translocation of FoxO1 from the nucleus to the cytoplasm significantly inactivated FoxO1 and activated the expression of cyclin D1 in nuclei of cardiac muscle cells. Reversal of adriamycin cardiomyopathy appeared to be mediated by dedifferentiation and proliferation of nuclear FoxO1-positive cardiac muscle cells with evidence of embryonic stem cell markers (OCT4, Nanog, SOX2 and c-kit), cardiac early differentiation markers (NKX2.5 and ISL-1) and cellular proliferation markers (BrdU and PHH3) after UTMD with GLP-1 gene therapy. Conclusions: Intranuclear myocardial delivery of the GLP-1gene can reverse established adriamycin cardiomyopathy by stimulating myocardial regeneration. - Highlights: • The activation of nuclear FoxO1 in cardiac muscle cells associated with adriamycin cardiomyopathy. • Myocardial nuclear GLP-1 stimulates myocardial regeneration and reverses adriamycin cardiomyopathy. • The process of myocardial regeneration associated with dedifferentiation and proliferation

  15. Augmentation of limb perfusion and reversal of tissue ischemia produced by ultrasound-mediated microbubble cavitation.

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    Belcik, J Todd; Mott, Brian H; Xie, Aris; Zhao, Yan; Kim, Sajeevani; Lindner, Nathan J; Ammi, Azzdine; Linden, Joel M; Lindner, Jonathan R

    2015-04-01

    Ultrasound can increase tissue blood flow, in part, through the intravascular shear produced by oscillatory pressure fluctuations. We hypothesized that ultrasound-mediated increases in perfusion can be augmented by microbubble contrast agents that undergo ultrasound-mediated cavitation and sought to characterize the biological mediators. Contrast ultrasound perfusion imaging of hindlimb skeletal muscle and femoral artery diameter measurement were performed in nonischemic mice after unilateral 10-minute exposure to intermittent ultrasound alone (mechanical index, 0.6 or 1.3) or ultrasound with lipid microbubbles (2×10(8) IV). Studies were also performed after inhibiting shear- or pressure-dependent vasodilator pathways, and in mice with hindlimb ischemia. Ultrasound alone produced a 2-fold increase (Pultrasound power. Ultrasound-mediated augmentation in flow was greater with microbubbles (3- and 10-fold higher than control for mechanical index 0.6 and 1.3, respectively; Pultrasound and microbubbles by 70% (Pultrasound and ultrasound with microbubbles. In mice with unilateral hindlimb ischemia (40%-50% reduction in flow), ultrasound (mechanical index, 1.3) with microbubbles increased perfusion by 2-fold to a degree that was greater than the control nonischemic limb. Increases in muscle blood flow during high-power ultrasound are markedly amplified by the intravascular presence of microbubbles and can reverse tissue ischemia. These effects are most likely mediated by cavitation-related increases in shear and activation of endothelial nitric oxide synthase. © 2015 American Heart Association, Inc.

  16. Mediated electrochemical hazardous waste destruction

    International Nuclear Information System (INIS)

    Hickman, R.G.; Farmer, J.C.; Wang, F.T.

    1992-03-01

    There are few permitted processes for mixed waste (radioactive plus chemically hazardous) treatment. We are developing an electrochemical process, based upon mediated electrochemical oxidation (MEO), that converts toxic organic components of mixed waste to water, carbon dioxide, and chloride or chloride precipitates. Aggressive oxidizer ions such as Ag 2+ , Co 3+ , or Fe 3+ are produced at an anode. These can attack organic molecules directly, and may also produce hydroxyl free radicals that promote destruction. Solid and liquid radioactive waste streams containing only inorganic radionuclide forms may be treated with existing technology and prepared for final disposal. The coulombic efficiency of the process has been determined, as well as the destruction efficiency for ethylene glycol, a surrogate waste. In addition, hazardous organic materials are becoming very expensive to dispose of and when they are combined with transuranic radioactive elements no processes are presently permitted. Mediated electrochemical oxidation is an ambient- temperature aqueous-phase process that can be used to oxidize organic components of mixed wastes. Problems associated with incineration, such as high-temperature volatilization of radionuclides, are avoided. Historically, Ag(II) has been used as a mediator in this process. Fe(III) and Co(III) are attractive alternatives to Ag(II) since they form soluble chlorides during the destruction of chlorinated solvents. Furthermore, silver itself is toxic heavy metal. Quantitative data have been obtained for the complete oxidation of ethylene glycol by Fe(III) and Co(III). Though ethylene glycol is a nonhalogenated organic, these data have enabled us to make direct comparisons of activities of Fe(III) and Co(III) with Ag(II). Very good quantitative data for the oxidation of ethylene glycol by Ag(II) had already been collected

  17. Ultrasound-mediated vascular gene transfection by cavitation of endothelial-targeted cationic microbubbles.

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    Xie, Aris; Belcik, Todd; Qi, Yue; Morgan, Terry K; Champaneri, Shivam A; Taylor, Sarah; Davidson, Brian P; Zhao, Yan; Klibanov, Alexander L; Kuliszewski, Michael A; Leong-Poi, Howard; Ammi, Azzdine; Lindner, Jonathan R

    2012-12-01

    Ultrasound-mediated gene delivery can be amplified by acoustic disruption of microbubble carriers that undergo cavitation. We hypothesized that endothelial targeting of microbubbles bearing cDNA is feasible and, through optimizing proximity to the vessel wall, increases the efficacy of gene transfection. Contrast ultrasound-mediated gene delivery is a promising approach for site-specific gene therapy, although there are concerns with the reproducibility of this technique and the safety when using high-power ultrasound. Cationic lipid-shelled decafluorobutane microbubbles bearing a targeting moiety were prepared and compared with nontargeted microbubbles. Microbubble targeting efficiency to endothelial adhesion molecules (P-selectin or intercellular adhesion molecule [ICAM]-1) was tested using in vitro flow chamber studies, intravital microscopy of tumor necrosis factor-alpha (TNF-α)-stimulated murine cremaster muscle, and targeted contrast ultrasound imaging of P-selectin in a model of murine limb ischemia. Ultrasound-mediated transfection of luciferase reporter plasmid charge coupled to microbubbles in the post-ischemic hindlimb muscle was assessed by in vivo optical imaging. Charge coupling of cDNA to the microbubble surface was not influenced by the presence of targeting ligand, and did not alter the cavitation properties of cationic microbubbles. In flow chamber studies, surface conjugation of cDNA did not affect attachment of targeted microbubbles at microvascular shear stresses (0.6 and 1.5 dyne/cm(2)). Attachment in vivo was also not affected by cDNA according to intravital microscopy observations of venular adhesion of ICAM-1-targeted microbubbles and by ultrasound molecular imaging of P-selectin-targeted microbubbles in the post-ischemic hindlimb in mice. Transfection at the site of high acoustic pressures (1.0 and 1.8 MPa) was similar for control and P-selectin-targeted microbubbles but was associated with vascular rupture and hemorrhage. At 0.6 MPa

  18. Mediated electrochemical hazardous waste destruction

    International Nuclear Information System (INIS)

    Hickman, R.G.; Farmer, J.C.; Wang, F.T.

    1991-08-01

    There are few permitted processes for mixed waste (radioactive plus chemically hazardous) treatment. We are developing electrochemical processes that convert the toxic organic components of mixed waste to water, carbon dioxide, an innocuous anions such as chloride. Aggressive oxidizer ions such as Ag 2+ or Ce +4 are produced at an anode. These can attack the organic molecules directly. They can also attack water which yields hydroxyl free radicals that in turn attack the organic molecules. The condensed (i.e., solid and/or liquid) effluent streams contain the inorganic radionuclide forms. These may be treated with existing technology and prepared for final disposal. Kinetics and the extent of destruction of some toxic organics have been measured. Depending on how the process is operated, coulombic efficiency can be nearly 100%. In addition, hazardous organic materials are becoming very expensive to dispose of and when they are combined with transuranic radioactive elements no processes are presently permitted. Mediated electrochemical oxidation is an ambient-temperature aqueous-phase process that can be used to oxidize organic components of mixed wastes. Problems associated with incineration, such as high-temperature volatilization of radionuclides, are avoided. Historically, Ag (2) has been used as a mediator in this process. Fe(6) and Co(3) are attractive alternatives to Ag(2) since they form soluble chlorides during the destruction of chlorinated solvents. Furthermore, silver itself is a toxic heavy metal. Quantitative data has been obtained for the complete oxidation of ethylene glycol by Fe(6) and Co(3). Though ethylene glycol is a nonhalogenated organic, this data has enabled us to make direct comparisons of activities of Fe(6) and Co(3) with Ag(2). Very good quantitative data for the oxidation of ethylene glycol by Ag(2) had already been collected. 4 refs., 6 figs

  19. Targeted gene delivery to the synovial pannus in antigen-induced arthritis by ultrasound-targeted microbubble destruction in vivo.

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    Xiang, Xi; Tang, Yuanjiao; Leng, Qianying; Zhang, Lingyan; Qiu, Li

    2016-02-01

    The purpose of this study was to optimize an ultrasound-targeted microbubble destruction (UTMD) technique to improve the in vivo transfection efficiency of the gene encoding enhanced green fluorescent protein (EGFP) in the synovial pannus in an antigen-induced arthritis rabbit model. A mixture of microbubbles and plasmids was locally injected into the knee joints of an antigen-induced arthritis (AIA) rabbits. The plasmid concentrations and ultrasound conditions were varied in the experiments. We also tested local articular and intravenous injections. The rabbits were divided into five groups: (1) ultrasound+microbubbles+plasmid; (2) ultrasound+plasmid; (3) microbubble+plasmid; (4) plasmid only; (5) untreated controls. EGFP expression was observed by fluorescent microscope and immunohistochemical staining in the synovial pannus of each group. The optimal plasmid dosage and ultrasound parameter were determined based on the results of EGFP expression and the present and absent of tissue damage under light microscopy. The irradiation procedure was performed to observe the duration of the EGFP expression in the synovial pannus and other tissues and organs, as well as the damage to the normal cells. The optimal condition was determined to be a 1-MHz ultrasound pulse applied for 5 min with a power output of 2 W/cm(2) and a 20% duty cycle along with 300 μg of plasmid. Under these conditions, the synovial pannus showed significant EGFP expression without significant damage to the surrounding normal tissue. The EGFP expression induced by the local intra-articular injection was significantly more increased than that induced by the intravenous injection. The EGFP expression in the synovial pannus of the ultrasound+microbubbles+plasmid group was significantly higher than that of the other four groups (Ppannus of an AIA model. Thus, this could become a safe and effective non-viral gene transfection procedure for arthritis therapy. Copyright © 2015 Elsevier B.V. All rights

  20. Effect of albumin and dextrose concentration on ultrasound and microbubble mediated gene transfection in vivo.

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    Browning, Richard J; Mulvana, Helen; Tang, Meng-Xing; Hajnal, Jo V; Wells, Dominic J; Eckersley, Robert J

    2012-06-01

    Ultrasound and microbubble mediated gene transfection has great potential for site-selective, safe gene delivery. Albumin-based microbubbles have shown the greatest transfection efficiency but have not been optimised specifically for this purpose. Additionally, few studies have highlighted desirable properties for transfection specific microbubbles. In this article, microbubbles were made with 2% or 5% (w/v) albumin and 20% or 40% (w/v) dextrose solutions, yielding four distinct bubble types. These were acoustically characterised and their efficiency in transfecting a luciferase plasmid (pGL4.13) into female, CD1 mice myocardia was measured. For either albumin concentration, increasing the dextrose concentration increased scattering, attenuation and resistance to ultrasound, resulting in significantly increased transfection. A significant interaction was noted between albumin and dextrose; 2% albumin bubbles made with 20% dextrose showed the least transfection but the most transfection with 40% dextrose. This trend was seen for both nonlinear scattering and attenuation behaviour but not for resistance to ultrasound or total scatter. We have determined that the attenuation behaviour is an important microbubble characteristic for effective gene transfection using ultrasound. Microbubble behaviour can also be simply controlled by altering the initial ingredients used during manufacture. Copyright © 2012 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  1. Advances in ultrasound-targeted microbubble-mediated gene therapy for liver fibrosis.

    Science.gov (United States)

    Huang, Cuiyuan; Zhang, Hong; Bai, Ruidan

    2017-07-01

    Hepatic fibrosis develops as a wound-healing scar in response to acute and chronic liver inflammation and can lead to cirrhosis in patients with chronic hepatitis B and C. The condition arises due to increased synthesis and reduced degradation of extracellular matrix (ECM) and is a common pathological sequela of chronic liver disease. Excessive deposition of ECM in the liver causes liver dysfunction, ascites, and eventually upper gastrointestinal bleeding as well as a series of complications. However, fibrosis can be reversed before developing into cirrhosis and has thus been the subject of extensive researches particularly at the gene level. Currently, therapeutic genes are imported into the damaged liver to delay or prevent the development of liver fibrosis by regulating the expression of exogenous genes. One technique of gene delivery uses ultrasound targeting of microbubbles combined with therapeutic genes where the time and intensity of the ultrasound can control the release process. Ultrasound irradiation of microbubbles in the vicinity of cells changes the permeability of the cell membrane by its cavitation effect and enhances gene transfection. In this paper, recent progress in the field is reviewed with emphasis on the following aspects: the types of ultrasound microbubbles, the construction of an ultrasound-mediated gene delivery system, the mechanism of ultrasound microbubble-mediated gene transfer and the application of ultrasound microbubbles in the treatment of liver fibrosis.

  2. Intravascular forward-looking ultrasound transducers for microbubble-mediated sonothrombolysis.

    Science.gov (United States)

    Kim, Jinwook; Lindsey, Brooks D; Chang, Wei-Yi; Dai, Xuming; Stavas, Joseph M; Dayton, Paul A; Jiang, Xiaoning

    2017-06-14

    Effective removal or dissolution of large blood clots remains a challenge in clinical treatment of acute thrombo-occlusive diseases. Here we report the development of an intravascular microbubble-mediated sonothrombolysis device for improving thrombolytic rate and thus minimizing the required dose of thrombolytic drugs. We hypothesize that a sub-megahertz, forward-looking ultrasound transducer with an integrated microbubble injection tube is more advantageous for efficient thrombolysis by enhancing cavitation-induced microstreaming than the conventional high-frequency, side-looking, catheter-mounted transducers. We developed custom miniaturized transducers and demonstrated that these transducers are able to generate sufficient pressure to induce cavitation of lipid-shelled microbubble contrast agents. Our technology demonstrates a thrombolysis rate of 0.7 ± 0.15 percent mass loss/min in vitro without any use of thrombolytic drugs.

  3. Advances in ultrasound-targeted microbubble-mediated gene therapy for liver fibrosis

    Directory of Open Access Journals (Sweden)

    Cuiyuan Huang

    2017-07-01

    Full Text Available Hepatic fibrosis develops as a wound-healing scar in response to acute and chronic liver inflammation and can lead to cirrhosis in patients with chronic hepatitis B and C. The condition arises due to increased synthesis and reduced degradation of extracellular matrix (ECM and is a common pathological sequela of chronic liver disease. Excessive deposition of ECM in the liver causes liver dysfunction, ascites, and eventually upper gastrointestinal bleeding as well as a series of complications. However, fibrosis can be reversed before developing into cirrhosis and has thus been the subject of extensive researches particularly at the gene level. Currently, therapeutic genes are imported into the damaged liver to delay or prevent the development of liver fibrosis by regulating the expression of exogenous genes. One technique of gene delivery uses ultrasound targeting of microbubbles combined with therapeutic genes where the time and intensity of the ultrasound can control the release process. Ultrasound irradiation of microbubbles in the vicinity of cells changes the permeability of the cell membrane by its cavitation effect and enhances gene transfection. In this paper, recent progress in the field is reviewed with emphasis on the following aspects: the types of ultrasound microbubbles, the construction of an ultrasound-mediated gene delivery system, the mechanism of ultrasound microbubble–mediated gene transfer and the application of ultrasound microbubbles in the treatment of liver fibrosis.

  4. Ultrasound-microbubble mediated cavitation of plant cells: effects on morphology and viability.

    Science.gov (United States)

    Qin, Peng; Xu, Lin; Zhong, Wenjing; Yu, Alfred C H

    2012-06-01

    The interaction between ultrasound pulses and microbubbles is known to generate acoustic cavitation that may puncture biological cells. This work presents new experimental findings on the bioeffects of ultrasound-microbubble mediated cavitation in plant cells with emphasis on direct observations of morphological impact and analysis of viability trends in tobacco BY-2 cells that are widely studied in higher plant physiology. The tobacco cell suspensions were exposed to 1 MHz ultrasound pulses in the presence of 1% v/v microbubbles (10% duty cycle; 1 kHz pulse repetition frequency; 70 mm between probe and cells; 1-min exposure time). Few bioeffects were observed at low peak negative pressures (cavitation presumably occurred. In contrast, at 0.9 MPa peak negative pressure (with more inertial cavitation activities according to our passive cavitation detection results), random pores were found on tobacco cell wall (observed via scanning electron microscopy) and enhanced exogenous uptake into the cytoplasm was evident (noted in our fluorescein isothiocyanate dextran uptake analysis). Also, instant lysis was observed in 23.4% of cells (found using trypan blue staining) and programmed cell death was seen in 23.3% of population after 12 h (determined by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling [TUNEL]). These bioeffects generally correspond in trend with those for mammalian cells. This raises the possibility of developing ultrasound-microbubble mediated cavitation into a targeted gene transfection paradigm for plant cells and, conversely, adopting plant cells as experimental test-beds for sonoporation-based gene therapy in mammalian cells. Copyright © 2012 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  5. Ablation of benign prostatic hyperplasia using microbubble-mediated ultrasound cavitation.

    Science.gov (United States)

    Li, Tao; Liu, Zheng

    2010-04-01

    Benign prostatic hyperplasia (BPH) is a world-wide common disease in elderly male patients. A number of invasive physiotherapies have been used to replace prostatectomy. In this article we report our hypothesis of using microbubbles-mediated ultrasound cavitation effects to ablate prostatic tissues. Microbubble ultrasound contrast agent is widely used contrast media in ultrasonography, yet it is also found to act as cavitation nuclei or enhancer. Once excited by a high peak pressure ultrasound pulse, the mechanical effects, like shock wave and microstream, released from cavitation could produce a series of bioeffects, contributing to sonoporation, microvascular rupture and hematoma. BPH is known to have hyperplastic neovasculature and this make it possible to be disrupted by the physical effects of cavitation under existing microbubbles in circulation. Mechanical ablation of prostatic capillary or small vessels could result in pathological alterations such as thrombosis, micro-circulation blockage, prostatic necrosis and atrophia. Thereupon it could effectively treat BPH by nontraumatic ways. (c) 2009 Elsevier Ltd. All rights reserved.

  6. Ablation of synovial pannus using microbubble-mediated ultrasonic cavitation in antigen-induced arthritis in rabbits.

    Science.gov (United States)

    Qiu, Li; Jiang, Yong; Zhang, Lingyan; Wang, Lei; Luo, Yan

    2012-12-01

    To investigate the ablative effectiveness of microbubble-mediated ultrasonic cavitation for treating synovial pannus and to determine a potential mechanism using the antigen-induced arthritis model (AIA). Ultrasonic ablation was performed on the knee joints of AIA rabbits using optimal ultrasonic ablative parameters. Rabbits with antigen-induced arthritis were randomly assigned to 4 groups: (1) the ultrasound (US) + microbubble group; (2) the US only group; (3) the microbubble only group, and (4) the control group. At 1 h and 14 days after the first ablation, contrast-enhanced ultrasonography (CEUS) monitoring and pathology synovitis score were used to evaluate the therapeutic effects. Synovial necrosis and microvascular changes were also measured. After the ablation treatment, the thickness of synovium and parameters of time intensity curve including derived peak intensity and area under curve were measured using CEUS, and the pathology synovitis score in the ultrasound + microbubble group was significantly lower than that found in the remaining groups. No damage was observed in the surrounding normal tissues. The mechanism underlying the ultrasonic ablation was related to microthrombosis and microvascular rupture that resulted in synovial necrosis. The results suggest that microbubble-mediated ultrasonic cavitation should be applied as a non-invasive strategy for the treatment of synovial pannus in arthritis under optimal conditions.

  7. Ultrasound-targeted microbubble destruction enhances delayed BMC delivery and attenuates post-infarction cardiac remodelling by inducing engraftment signals.

    Science.gov (United States)

    Chen, Yanmei; Zhang, Chuanxi; Shen, Shuxin; Guo, Shengcun; Zhong, Lintao; Li, Xinzhong; Chen, Guojun; Chen, Gangbin; He, Xiang; Huang, Chixiong; He, Nvqin; Liao, Wangjun; Liao, Yulin; Bin, Jianping

    2016-12-01

    Delayed administration of bone marrow cells (BMCs) at 2-4 weeks after successful reperfusion in patients with acute myocardial infarction (MI) does not improve cardiac function. The reduction in engraftment signals observed following this time interval might impair the effects of delayed BMC treatment. In the present study, we aimed to determine whether ultrasound-targeted microbubble destruction (UTMD) treatment could increase engraftment signals, enhance the delivery of delayed BMCs and subsequently attenuate post-infarction cardiac remodelling. A myocardial ischaemia/reperfusion (I/R) model was induced in Wistar rats via left coronary ligation for 45 min followed by reperfusion. Western blotting revealed that engraftment signals peaked at 7 days post-I/R and were dramatically lower at 14 days post-I/R. The lower engraftment signals at 14 days post-I/R could be triggered by UTMD treatment at a mechanical index of 1.0-1.9. The troponin I levels in the 1.9 mechanical index group were higher than in the other groups. Simultaneous haematoxylin and eosin staining and fluorescence revealed that the number of engrafted BMCs in the ischaemic zone was greater in the group treated with both UTMD and delayed BMC transplantation than in the control groups (PBMC transplantation improved cardiac function and decreased cardiac fibrosis at 4 weeks after treatment, as compared with control groups (both PBMC transplantation increased capillary density, myocardial cell proliferation and c-kit + cell proliferation. These findings indicated that UTMD treatment could induce engraftment signals and enhance homing of delayed BMCs to ischaemic myocardium, attenuating post-infarction cardiac remodelling by promoting neovascularization, cardiomyogenesis and expansion of cardiac c-kit + cells. © 2016 The Author(s). published by Portland Press Limited on behalf of the Biochemical Society.

  8. Ultrasound-targeted stromal cell-derived factor-1-loaded microbubble destruction promotes mesenchymal stem cell homing to kidneys in diabetic nephropathy rats

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    Wu S

    2014-12-01

    Full Text Available Shengzheng Wu,1 Lu Li,1 Gong Wang,1 Weiwei Shen,2 Yali Xu,1 Zheng Liu,1 Zhongxiong Zhuo,1 Hongmei Xia,1 Yunhua Gao,1 Kaibin Tan1 1Department of Ultrasound, 2Department of Orthopedics, Xinqiao Hospital, Third Military Medical University, Chongqing, People’s Republic of China Abstract: Mesenchymal stem cell (MSC therapy has been considered a promising strategy to cure diabetic nephropathy (DN. However, insufficient MSCs can settle in injured kidneys, which constitute one of the major barriers to the effective implementation of MSC therapy. Stromal cell-derived factor-1 (SDF-1 plays a vital role in MSC migration and involves activation, mobilization, homing, and retention, which are presumably related to the poor homing in DN therapy. Ultrasound-targeted microbubble destruction has become one of the most promising strategies for the targeted delivery of drugs and genes. To improve MSC homing to DN kidneys, we present a strategy to increase SDF-1 via ultrasound-targeted microbubble destruction. In this study, we developed SDF-1-loaded microbubbles (MBSDF-1 via covalent conjugation. The characterization and bioactivity of MBSDF-1 were assessed in vitro. Target release in the targeted kidneys was triggered with diagnostic ultrasound in combination with MBSDF-1. The related bioeffects were also elucidated. Early DN was induced in rats with streptozotocin. Green fluorescent protein-labeled MSCs were transplanted intravenously following the target release of SDF-1 in the kidneys of normal and DN rats. The homing efficacy was assessed by detecting the implanted exogenous MSCs at 24 hours. The in vitro results showed an impressive SDF-1 loading efficacy of 79% and a loading content of 15.8 µg/mL. MBSDF-1 remained bioactive as a chemoattractant. In the in vivo study, SDF-1 was successfully released in the targeted kidneys. The homing efficacy of MSCs to DN kidneys after the target release of SDF-1 was remarkably ameliorated at 24 hours compared with

  9. Transfection of CXCR-4 using microbubble-mediated ultrasound irradiation and liposomes improves the migratory ability of bone marrow stromal cells.

    Science.gov (United States)

    Wang, Gong; Zhuo, Zhongxiong; Zhang, Qian; Xu, Yali; Wu, Shengzheng; Li, Lu; Xia, Hongmei; Gao, Yunhua

    2015-01-01

    Bone marrow stromal cells (BMSCs) have proven useful for the treatment of various human diseases and injuries. However, their reparative capacity is limited by their poor migration and homing ability, which are primarily dependent on the SDF-1/CXCR4 axis. Most subcultured BMSCs lack CXCR4 receptor expression on the cell surface and exhibit impaired migratory capacity. To increase responsiveness to SDF-1 and promote cell migration and survival of cultured BMSCs, we used a combination of ultrasound-targeted microbubble destruction (UTMD) and liposomes to increase CXCR4 expression in vitro. We isolated and cultured rat BMSCs to their third passage and transduced them with recombinant plasmid pDsRed-CXCR4 using microbubble-mediated ultrasound irradiation and liposomes. Compared to some viral vectors, the method we employed here resulted in significantly better transfection efficiency, CXCR4 expression, and technical reproducibility. The benefits of this approach are likely due to the combination of "sonoporation" caused by shockwaves and microjet flow resulting from UTMD-generated cavitation. Following transfection, we performed a transwell migration assay and found that the migration ability of CXCR4-modified BMSCs was 9-fold higher than controls. The methods we describe here provide an effective, safe, non-viral means to achieve high levels of CXCR4 expression. This is associated with enhanced migration of subcultured BMSCs and may be useful for clinical application as well.

  10. The dynamic behavior of microbubbles during long ultrasound tone-burst excitation: mechanistic insights into ultrasound-microbubble mediated therapeutics using high-speed imaging and cavitation detection

    Science.gov (United States)

    Pacella, John J.; Villanueva, Flordeliza S.

    2015-01-01

    Ultrasound (US)-microbubble (MB) mediated therapies have been shown to restore perfusion and enhance drug/gene delivery. Due to the presumption that MBs do not persist during long US exposure under high acoustic pressures, most schemes utilize short US pulses when a high US pressure is employed. However, we recently observed an enhanced thrombolytic effect using long US pulses at high acoustic pressures. Therefore we explored the fate of MBs during long tone-burst exposures (5 ms) at various acoustic pressures and MB concentrations via direct high-speed optical observation and passive cavitation detection. MBs first underwent stable or inertial cavitation depending on the acoustic pressure, and then formed gas-filled clusters that continued to oscillate, break up, and form new clusters. Cavitation detection confirmed continued, albeit diminishing acoustic activity throughout the 5-ms US excitation. These data suggest that persisting cavitation activity during long tone-bursts may confer additional therapeutic effects. PMID:26603628

  11. Cardiac Gene Expression Knockdown Using Small Inhibitory RNA-Loaded Microbubbles and Ultrasound.

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    Jonathan A Kopechek

    Full Text Available RNA interference has potential therapeutic value for cardiac disease, but targeted delivery of interfering RNA is a challenge. Custom designed microbubbles, in conjunction with ultrasound, can deliver small inhibitory RNA to target tissues in vivo. The efficacy of cardiac RNA interference using a microbubble-ultrasound theranostic platform has not been demonstrated in vivo. Therefore, our objective was to test the hypothesis that custom designed microbubbles and ultrasound can mediate effective delivery of small inhibitory RNA to the heart. Microbubble and ultrasound mediated cardiac RNA interference was tested in transgenic mice displaying cardiac-restricted luciferase expression. Luciferase expression was assayed in select tissues of untreated mice (n = 14. Mice received intravenous infusion of cationic microbubbles bearing small inhibitory RNA directed against luciferase (n = 9 or control RNA (n = 8 during intermittent cardiac-directed ultrasound at mechanical index of 1.6. Simultaneous echocardiography in a separate group of mice (n = 3 confirmed microbubble destruction and replenishment during treatment. Three days post treatment, cardiac luciferase messenger RNA and protein levels were significantly lower in ultrasound-treated mice receiving microbubbles loaded with small inhibitory RNA directed against luciferase compared to mice receiving microbubbles bearing control RNA (23±7% and 33±7% of control mice, p<0.01 and p = 0.03, respectively. Passive cavitation detection focused on the heart confirmed that insonification resulted in inertial cavitation. In conclusion, small inhibitory RNA-loaded microbubbles and ultrasound directed at the heart significantly reduced the expression of a reporter gene. Ultrasound-targeted destruction of RNA-loaded microbubbles may be an effective image-guided strategy for therapeutic RNA interference in cardiac disease.

  12. Engineering brown fat into skeletal muscle using ultrasound-targeted microbubble destruction gene delivery in obese Zucker rats: Proof of concept design.

    Science.gov (United States)

    Bastarrachea, Raul A; Chen, Jiaxi; Kent, Jack W; Nava-Gonzalez, Edna J; Rodriguez-Ayala, Ernesto; Daadi, Marcel M; Jorge, Barbara; Laviada-Molina, Hugo; Comuzzie, Anthony G; Chen, Shuyuan; Grayburn, Paul A

    2017-09-01

    Ultrasound-targeted microbubble destruction (UTMD) is a novel means of tissue-specific gene delivery. This approach systemically infuses transgenes precoupled to gas-filled lipid microbubbles that are burst within the microvasculature of target tissues via an ultrasound signal resulting in release of DNA and transfection of neighboring cells within the tissue. Previous work has shown that adenovirus containing cDNA of UCP-1, injected into the epididymal fat pads in mice, induced localized fat depletion, improving glucose tolerance, and decreasing food intake in obese diabetic mice. Our group recently demonstrated that gene therapy by UTMD achieved beta cell regeneration in streptozotocin (STZ)-treated mice and baboons. We hypothesized that gene therapy with BMP7/PRDM16/PPARGC1A in skeletal muscle (SKM) of obese Zucker diabetic fatty (fa/fa) rats using UTMD technology would produce a brown adipose tissue (BAT) phenotype with UCP-1 overexpression. This study was designed as a proof of concept (POC) project. Obese Zucker rats were administered plasmid cDNA contructs encoding a gene cocktail with BMP7/PRDM16/PPARGC1A incorporated within microbubbles and intravenously delivered into their left thigh. Controls received UTMD with plasmids driving a DsRed reporter gene. An ultrasound transducer was directed to the thigh to disrupt the microbubbles within the microcirculation. Blood samples were drawn at baseline, and after treatment to measure glucose, insulin, and free fatty acids levels. SKM was harvested for immunohistochemistry (IHC). Our IHC results showed a reliable pattern of effective UTMD-based gene delivery in enhancing SKM overexpression of the UCP-1 gene. This clearly indicates that our plasmid DNA construct encoding the gene combination of PRDM16, PPARGC1A, and BMP7 reprogrammed adult SKM tissue into brown adipose cells in vivo. Our pilot established POC showing that the administration of the gene cocktail to SKM in this rat model of genetic obesity using UTMD

  13. Ultrasound Microbubble Treatment Enhances Clathrin-Mediated Endocytosis and Fluid-Phase Uptake through Distinct Mechanisms.

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    Farnaz Fekri

    Full Text Available Drug delivery to tumors is limited by several factors, including drug permeability of the target cell plasma membrane. Ultrasound in combination with microbubbles (USMB is a promising strategy to overcome these limitations. USMB treatment elicits enhanced cellular uptake of materials such as drugs, in part as a result of sheer stress and formation of transient membrane pores. Pores formed upon USMB treatment are rapidly resealed, suggesting that other processes such as enhanced endocytosis may contribute to the enhanced material uptake by cells upon USMB treatment. How USMB regulates endocytic processes remains incompletely understood. Cells constitutively utilize several distinct mechanisms of endocytosis, including clathrin-mediated endocytosis (CME for the internalization of receptor-bound macromolecules such as Transferrin Receptor (TfR, and distinct mechanism(s that mediate the majority of fluid-phase endocytosis. Tracking the abundance of TfR on the cell surface and the internalization of its ligand transferrin revealed that USMB acutely enhances the rate of CME. Total internal reflection fluorescence microscopy experiments revealed that USMB treatment altered the assembly of clathrin-coated pits, the basic structural units of CME. In addition, the rate of fluid-phase endocytosis was enhanced, but with delayed onset upon USMB treatment relative to the enhancement of CME, suggesting that the two processes are distinctly regulated by USMB. Indeed, vacuolin-1 or desipramine treatment prevented the enhancement of CME but not of fluid phase endocytosis upon USMB, suggesting that lysosome exocytosis and acid sphingomyelinase, respectively, are required for the regulation of CME but not fluid phase endocytosis upon USMB treatment. These results indicate that USMB enhances both CME and fluid phase endocytosis through distinct signaling mechanisms, and suggest that strategies for potentiating the enhancement of endocytosis upon USMB treatment may

  14. Multifactorial aspects of antibody-mediated blood cell destruction

    NARCIS (Netherlands)

    Kapur, R.

    2014-01-01

    The research described in this thesis focuses on diseases of antibody-mediated blood cell destruction via FcγRs on phagocytes, in particular regarding platelets in fetal or neonatal alloimmune thrombocytopenia (FNAIT) and red blood cells (RBC) in hemolytic disease of the fetus and newborn (HDFN).

  15. Theranastic USPIO-loaded microbubbles for mediating and monitoring blood-brain barrier permeation

    NARCIS (Netherlands)

    Lammers, Twan Gerardus Gertudis Maria; Koczera, Patrick; Fokong, Stanley; Gremse, Felix; Ehling, Josef; Vogt, Michael; Pich, Andrij; Storm, Gerrit; van Zandvoort, Marc; Kiessling, Fabian

    2015-01-01

    Efficient and safe drug delivery across the blood-brain barrier (BBB) remains one of the major challenges of biomedical and (nano-) pharmaceutical research. Here, it is demonstrated that poly(butyl cyanoacrylate)-based microbubbles (MB), carrying ultrasmall superparamagnetic iron oxide (USPIO)

  16. Theranostic USPIO-loaded microbubbles for mediating and monitoring blood-brain barrier permeation

    NARCIS (Netherlands)

    Lammers, Twan; Koczera, Patrick; Fokong, Stanley; Gremse, Felix; Ehling, Josef; Vogt, Michael; Pich, Andrij; Storm, G; Van Zandvoort, Marc; Kiessling, Fabian

    2015-01-01

    Efficient and safe drug delivery across the blood-brain barrier (BBB) remains one of the major challenges of biomedical and (nano-) pharmaceutical research. Here, it is demonstrated that poly(butyl cyanoacrylate)-based microbubbles (MB), carrying ultrasmall superparamagnetic iron oxide (USPIO)

  17. Ultrasound-Targeted Microbubble Destruction Improves the Migration and Homing of Mesenchymal Stem Cells after Myocardial Infarction by Upregulating SDF-1/CXCR4: A Pilot Study

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    Lu Li

    2015-01-01

    Full Text Available Mesenchymal stem cell (MSC therapy shows considerable promise for the treatment of myocardial infarction (MI. However, the inefficient migration and homing of MSCs after systemic infusion have limited their therapeutic applications. Ultrasound-targeted microbubble destruction (UTMD has proven to be promising to improve the homing of MSCs to the ischemic myocardium, but the concrete mechanism remains unclear. We hypothesize that UTMD promotes MSC homing by upregulating SDF-1/CXCR4, and this study was aimed at exploring this potential mechanism. We analyzed SDF-1/CXCR4 expression after UTMD treatment in vitro and in vivo and counted the number of homing MSCs in MI areas. The in vitro results demonstrated that UTMD not only led to elevated secretion of SDF-1 but also resulted in an increased proportion of MSCs that expressed surface CXCR4. The in vivo findings show an increase in the number of homing MSCs and higher expression of SDF-1/CXCR4 in the UTMD combined with MSCs infusion group compared to other groups. In conclusion, UTMD can increase SDF-1 expression in the ischemic myocardium and upregulate the expression of surface CXCR4 on MSCs, which provides a molecular mechanism for the homing of MSCs assisted by UTMD via SDF-1/CXCR4 axis.

  18. A multi-frequency sparse hemispherical ultrasound phased array for microbubble-mediated transcranial therapy and simultaneous cavitation mapping.

    Science.gov (United States)

    Deng, Lulu; O'Reilly, Meaghan A; Jones, Ryan M; An, Ran; Hynynen, Kullervo

    2016-12-21

    Focused ultrasound (FUS) phased arrays show promise for non-invasive brain therapy. However, the majority of them are limited to a single transmit/receive frequency and therefore lack the versatility to expose and monitor the treatment volume. Multi-frequency arrays could offer variable transmit focal sizes under a fixed aperture, and detect different spectral content on receive for imaging purposes. Here, a three-frequency (306, 612, and 1224 kHz) sparse hemispherical ultrasound phased array (31.8 cm aperture; 128 transducer modules) was constructed and evaluated for microbubble-mediated transcranial therapy and simultaneous cavitation mapping. The array is able to perform effective electronic beam steering over a volume spanning (-40, 40) and (-30, 50) mm in the lateral and axial directions, respectively. The focal size at the geometric center is approximately 0.9 (2.1) mm, 1.7 (3.9) mm, and 3.1 (6.5) mm in lateral (axial) pressure full width at half maximum (FWHM) at 1224, 612, and 306 kHz, respectively. The array was also found capable of dual-frequency excitation and simultaneous multi-foci sonication, which enables the future exploration of more complex exposure strategies. Passive acoustic mapping of dilute microbubble clouds demonstrated that the point spread function of the receive array has a lateral (axial) intensity FWHM between 0.8-3.5 mm (1.7-11.7 mm) over a volume spanning (-25, 25) mm in both the lateral and axial directions, depending on the transmit/receive frequency combination and the imaging location. The device enabled both half and second harmonic imaging through the intact skull, which may be useful for improving the contrast-to-tissue ratio or imaging resolution, respectively. Preliminary in vivo experiments demonstrated the system's ability to induce blood-brain barrier opening and simultaneously spatially map microbubble cavitation activity in a rat model. This work presents a tool to investigate optimal strategies for non

  19. Functional and pathological improvements of the hearts in diabetes model by the combined therapy of bFGF-loaded nanoparticles with ultrasound-targeted microbubble destruction.

    Science.gov (United States)

    Zhao, Ying-Zheng; Tian, Xin-Qiao; Zhang, Ming; Cai, Lu; Ru, Ao; Shen, Xiao-Tong; Jiang, Xi; Jin, Rong-Rong; Zheng, Lei; Hawkins, Kyle; Charkrabarti, Subrata; Li, Xiao-Kun; Lin, Qian; Yu, Wen-Ze; Ge, Shuping; Lu, Cui-Tao; Wong, Ho Lun

    2014-07-28

    Diabetic cardiomyopathy (DCM) is the leading cause of morbidity and mortality among the diabetic patients and currently there is no effective means to reverse its pathological progress. Basic fibroblast growth factor (bFGF) has shown promise as a molecular therapy for DCM, but its delivery is inefficient and non-specific. In the present study, a therapy combining nanoparticle (NP) carrier and ultrasound-targeted microbubble destruction (UTMD) was reported the first time for bFGF delivery to the heart of diabetic rats. bFGF-loaded NP (bFGF-NP) were prepared with Poloxamer 188-grafted heparin copolymer using water-in-water technique, and the morphology, encapsulation efficiency, and bioactivity of bFGF-NP were studied. The cellular uptake and cytotoxicity of bFGF-NP were evaluated with primary cultures of the left ventricular (LV) cardiomyocytes in vitro. Therapeutic effects of bFGF-NP/UTMD on the heart of DCM rats were studied by measuring LV systolic and diastolic functions, hemodynamic characteristics and indicators of cardiac remodeling including myocardial collagen volume fraction and capillary density. Results demonstrated that bFGF-NP showed good round morphology, efficient bFGF encapsulation and stable bioactivity of bFGF in vitro. bFGF-NP/UTMD combined treatment significantly enhanced the efficiency of bFGF cellular uptake (Pfunctions and tissue morphology in the DCM rats were observed in bFGF-NP/UTMD group. These were not achievable using free bFGF, bFGF-NP or UTMD treatment alone. Our results show that combining a non-viral vector with UTMD technique is an effective strategy to deliver bFGF to the heart, and the resulting growth factor therapy has demonstrated potential to reverse the progress of DCM by restoring the cardiac functions and even the structure of damaged cardiac tissues. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Effects of Microbubble Size on Ultrasound-Mediated Gene Transfection in Auditory Cells

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    Ai-Ho Liao

    2014-01-01

    Full Text Available Gene therapy for sensorineural hearing loss has recently been used to insert genes encoding functional proteins to preserve, protect, or even regenerate hair cells in the inner ear. Our previous study demonstrated a microbubble- (MB-facilitated ultrasound (US technique for delivering therapeutic medication to the inner ear. The present study investigated whether MB-US techniques help to enhance the efficiency of gene transfection by means of cationic liposomes on HEI-OC1 auditory cells and whether MBs of different sizes affect such efficiency. Our results demonstrated that the size of MBs was proportional to the concentration of albumin or dextrose. At a constant US power density, using 0.66, 1.32, and 2.83 μm albumin-shelled MBs increased the transfection rate as compared to the control by 30.6%, 54.1%, and 84.7%, respectively; likewise, using 1.39, 2.12, and 3.47 μm albumin-dextrose-shelled MBs increased the transfection rates by 15.9%, 34.3%, and 82.7%, respectively. The results indicate that MB-US is an effective technique to facilitate gene transfer on auditory cells in vitro. Such size-dependent MB oscillation behavior in the presence of US plays a role in enhancing gene transfer, and by manipulating the concentration of albumin or dextrose, MBs of different sizes can be produced.

  1. Microbubbles coupled to methotrexate-loaded liposomes for ultrasound-mediated delivery of methotrexate across the blood–brain barrier

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    Wang X

    2014-10-01

    Full Text Available Xiang Wang,1 Ping Liu,1 Weixiao Yang,1 Lu Li,1 Peijing Li,2 Zheng Liu,1 Zhongxiong Zhuo,1 Yunhua Gao1 1Department of Ultrasound, Xinqiao Hospital of the Third Military Medical University, Chongqing, 2Department of Ultrasound, General Hospital of the Jinan Military Area, Jinan, People’s Republic of China Abstract: Methotrexate (MTX is the single most effective agent for the treatment of primary central nervous system lymphoma. Currently, the delivery of MTX to the brain is achieved by high systemic doses, which cause severe long-term neurotoxicity, or intrathecal administration, which is highly invasive and may lead to infections or hemorrhagic complications. Acoustically active microbubbles have been developed as drug carriers for the noninvasive and brain-targeted delivery of therapeutics. However, their application is limited by their low drug-loading capacity. To overcome this limitation, we prepared microbubbles coupled to MTX-loaded liposomes using ZHIFUXIAN, a novel type of microbubbles with a superior safety profile and long circulation time. MTX-liposome-coupled microbubbles had a high drug-loading capacity of 8.91%±0.86%, and their size (2.64±0.93 µm in diameter was suitable for intravenous injection. When used with ultrasound, they showed more potent in vitro cytotoxicity against Walker-256 cancer cells than MTX alone or MTX-loaded liposomes. When Sprague-Dawley rats were exposed to sonication, administration of these MTX-liposome-coupled microbubbles via the tail vein led to targeted disruption of the blood–brain barrier without noticeable tissue or capillary damage. High-performance liquid chromatography analysis of the brain MTX concentration showed that MTX delivery to the brain followed the order of MTX-liposome-coupled microbubbles + ultrasound (25.3±2.4 µg/g > unmodified ZHIFUXIAN + MTX + ultrasound (18.6±2.2 µg/g > MTX alone (6.97±0.75 µg/g > MTX-liposome-coupled microbubbles (2.92±0.39 µg/g. Therefore

  2. Ultrasound-mediated microbubble enhancement of radiation therapy studied using three-dimensional high-frequency power Doppler ultrasound.

    Science.gov (United States)

    Kwok, Sheldon J J; El Kaffas, Ahmed; Lai, Priscilla; Al Mahrouki, Azza; Lee, Justin; Iradji, Sara; Tran, William Tyler; Giles, Anoja; Czarnota, Gregory J

    2013-11-01

    Tumor responses to high-dose (>8 Gy) radiation therapy are tightly connected to endothelial cell death. In the study described here, we investigated whether ultrasound-activated microbubbles can locally enhance tumor response to radiation treatments of 2 and 8 Gy by mechanically perturbing the endothelial lining of tumors. We evaluated vascular changes resulting from combined microbubble and radiation treatments using high-frequency 3-D power Doppler ultrasound in a breast cancer xenograft model. We compared treatment effects and monitored vasculature damage 3 hours, 24 hours and 7 days after treatment delivery. Mice treated with 2 Gy radiation and ultrasound-activated microbubbles exhibited a decrease in vascular index to 48 ± 10% at 24 hours, whereas vascular indices of mice treated with 2 Gy radiation alone or microbubbles alone were relatively unchanged at 95 ± 14% and 78 ± 14%, respectively. These results suggest that ultrasound-activated microbubbles enhance the effects of 2 Gy radiation through a synergistic mechanism, resulting in alterations of tumor blood flow. This novel therapy may potentiate lower radiation doses to preferentially target endothelial cells, thus reducing effects on neighboring normal tissue and increasing the efficacy of cancer treatments. Crown Copyright © 2013. Published by Elsevier Inc. All rights reserved.

  3. Fluidic oscillator-mediated microbubble generation to provide cost effective mass transfer and mixing efficiency to the wastewater treatment plants.

    Science.gov (United States)

    Rehman, Fahad; Medley, Gareth J D; Bandulasena, Hemaka; Zimmerman, William B J

    2015-02-01

    Aeration is one of the most energy intensive processes in the waste water treatment plants and any improvement in it is likely to enhance the overall efficiency of the overall process. In the current study, a fluidic oscillator has been used to produce microbubbles in the order of 100 μm in diameter by oscillating the inlet gas stream to a pair of membrane diffusers. Volumetric mass transfer coefficient was measured for steady state flow and oscillatory flow in the range of 40-100l/min. The highest improvement of 55% was observed at the flow rates of 60, 90 and 100l/min respectively. Standard oxygen transfer rate and efficiency were also calculated. Both standard oxygen transfer rate and efficiency were found to be considerably higher under oscillatory air flow conditions compared to steady state airflow. The bubble size distributions and bubble densities were measured using an acoustic bubble spectrometer and confirmed production of monodisperse bubbles with approximately 100 μm diameters with fluidic oscillation. The higher number density of microbubbles under oscillatory flow indicated the effect of the fluidic oscillation in microbubble production. Visual observations and dissolved oxygen measurements suggested that the bubble cloud generated by the fluidic oscillator was sufficient enough to provide good mixing and to maintain uniform aerobic conditions. Overall, improved mass transfer coefficients, mixing efficiency and energy efficiency of the novel microbubble generation method could offer significant savings to the water treatment plants as well as reduction in the carbon footprint. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Dynamic Behavior of Microbubbles during Long Ultrasound Tone-Burst Excitation: Mechanistic Insights into Ultrasound-Microbubble Mediated Therapeutics Using High-Speed Imaging and Cavitation Detection.

    Science.gov (United States)

    Chen, Xucai; Wang, Jianjun; Pacella, John J; Villanueva, Flordeliza S

    2016-02-01

    Ultrasound (US)-microbubble (MB)-mediated therapies have been found to restore perfusion and enhance drug/gene delivery. On the presumption that MBs do not persist during long US exposure under high acoustic pressures, most schemes use short US pulses when a high US pressure is employed. However, we recently observed an enhanced thrombolytic effect using long US pulses at high acoustic pressures. Therefore, we explored the fate of MBs during long tone-burst exposures (5 ms) at various acoustic pressures and MB concentrations via direct high-speed optical observation and passive cavitation detection. MBs first underwent stable or inertial cavitation depending on the acoustic pressure and then formed gas-filled clusters that continued to oscillate, break up and form new clusters. Cavitation detection confirmed continued, albeit diminishing, acoustic activity throughout the 5-ms US excitation. These data suggest that persisting cavitation activity during long tone bursts may confer additional therapeutic effects. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  5. Lung Surfactant Microbubbles Increase Lipophilic Drug Payload for Ultrasound-Targeted Delivery

    OpenAIRE

    Sirsi, Shashank R.; Fung, Chinpong; Garg, Sumit; Tianning, Mary Y.; Mountford, Paul A.; Borden, Mark A.

    2013-01-01

    The cavitation response of circulating microbubbles to targeted ultrasound can be used for noninvasive, site-specific delivery of shell-loaded materials. One challenge for microbubble-mediated delivery of lipophilic compounds is the limitation of drug loading into the microbubble shell, which is commonly a single phospholipid monolayer. In this study, we investigated the use of natural lung surfactant extract (Survanta?, Abbott Nutrition) as a microbubble shell material in order to improve dr...

  6. Destruction of commercial pesticides by cerium redox couple mediated electrochemical oxidation process in continuous feed mode

    International Nuclear Information System (INIS)

    Balaji, Subramanian; Chung, Sang Joon; Ryu, Jae-Yong; Moon, Il Shik

    2009-01-01

    Mediated electrochemical oxidation was carried out for the destruction of commercial pesticide formulations using cerium(IV) in nitric acid as the mediator electrolyte solution in a bench scale set up. The mediator oxidant was regenerated in situ using an electrochemical cell. The real application of this sustainable process for toxic organic pollutant destruction lies in its ability for long term continuous operation with continuous organic feeding and oxidant regeneration with feed water removal. In this report we present the results of fully integrated MEO system. The task of operating the continuous feed MEO system for a long time was made possible by continuously removing the feed water using an evaporator set up. The rate of Ce(IV) regeneration in the electrochemical cell and the consumption for the pesticide destruction was matched based on carbon content of the pesticides. It was found that under the optimized experimental conditions for Ce(III) oxidation, organic addition and water removal destruction efficiency of ca. 99% was obtained for all pesticides studied. It was observed that the Ce(IV) concentration was maintained nearly the same throughout the experiment. The stable operation for 6 h proved that the process can be used for real applications and for possible scale up for the destruction of larger volumes of toxic organic wastes.

  7. Role of periodontal pathogenic bacteria in RANKL-mediated bone destruction in periodontal disease

    OpenAIRE

    Mikihito Kajiya; Gabriela Giro; Martin A. Taubman; Xiaozhe Han; Marcia P.A. Mayer; Toshihisa Kawai

    2010-01-01

    Accumulated lines of evidence suggest that hyperimmune responses to periodontal bacteria result in the destruction of periodontal connective tissue and alveolar bone. The etiological roles of periodontal bacteria in the onset and progression of periodontal disease (PD) are well documented. However, the mechanism underlying the engagement of periodontal bacteria in RANKL-mediated alveolar bone resorption remains unclear. Therefore, this review article addresses three critical subjects. First, ...

  8. Sonodynamically-induced cytotoxicity by rose bengal derivative and microbubbles in isolated sarcoma 180 cells

    Science.gov (United States)

    Sugita, Nami; Hosokawa, Mami; Sunaga, Naoki; Iwase, Yumiko; Yumita, Nagahiko; Ikeda, Toshihiko; Umemura, Shin-ichiro

    2015-07-01

    It is known that the combination of ultrasound and sonodynamic sensitizer (SDS) is effective in noninvasive tumor treatment, referred to as sonodynamic therapy (SDT). Microbubbles have been used in ultrasound therapy as well. The purpose of this paper is to clarify the effect of microbubbles on SDT. Sarcoma 180 cells were suspended in air-saturated phosphate-buffered saline and exposed to ultrasound with the SDS rose bengal derivative (RBD) in standing wave mode in the presence and absence of microbubbles [sonazoid (SZ)]. The ultrasonically induced cytotoxicity with RBD and SZ was about 20 times higher than without either, and about 80% of the SZ microbubbles were destructed by ultrasonic exposure in as short as five seconds. Since microbubbles induce significant cytotoxicity even with short duration, low intensity ultrasound, the application of microbubbles in SDT shows promise in anti-tumor treatment.

  9. Lung surfactant microbubbles increase lipophilic drug payload for ultrasound-targeted delivery.

    Science.gov (United States)

    Sirsi, Shashank R; Fung, Chinpong; Garg, Sumit; Tianning, Mary Y; Mountford, Paul A; Borden, Mark A

    2013-01-01

    The cavitation response of circulating microbubbles to targeted ultrasound can be used for noninvasive, site-specific delivery of shell-loaded materials. One challenge for microbubble-mediated delivery of lipophilic compounds is the limitation of drug loading into the microbubble shell, which is commonly a single phospholipid monolayer. In this study, we investigated the use of natural lung surfactant extract (Survanta(®), Abbott Nutrition) as a microbubble shell material in order to improve drug payload and delivery. Pulmonary surfactant extracts such as Survanta contain hydrophobic surfactant proteins (SP-B and SP-C) that facilitate lipid folding and retention on lipid monolayers. Here, we show that Survanta-based microbubbles exhibit wrinkles in bright-field microscopy and increased lipid retention on the microbubble surface in the form of surface-associated aggregates observed with fluorescence microscopy. The payload of a model lipophilic drug (DiO), measured by flow cytometry, increased by over 2-fold compared to lipid-coated microbubbles lacking SP-B and SP-C. Lung surfactant microbubbles were highly echogenic to contrast enhanced ultrasound imaging at low acoustic intensities. At higher ultrasound intensity, excess lipid was observed to be acoustically cleaved for localized release. To demonstrate targeting, a biotinylated lipopolymer was incorporated into the shell, and the microbubbles were subjected to a sequence of radiation force and fragmentation pulses as they passed through an avidinated hollow fiber. Lung surfactant microbubbles showed a 3-fold increase in targeted deposition of the model fluorescent drug compared to lipid-only microbubbles. Our results demonstrate that lung surfactant microbubbles maintain the acoustic responsiveness of lipid-coated microbubbles with the added benefit of increased lipophilic drug payload.

  10. Microbubbles for medical applications

    NARCIS (Netherlands)

    Segers, T.J.; de Jong, N.; Lohse, Detlef; Versluis, Michel; van den Berg, A.; Segerink, L.

    2015-01-01

    Ultrasound contrast agent (UCA) suspensions contain encapsulated microbubbles with radii ranging from 1 to 10 micrometers. The bubbles oscillate to the driving ultrasound pulse generating harmonics of the driving ultrasound frequency. This feature allows for the discrimination of non-linear bubble

  11. Role of periodontal pathogenic bacteria in RANKL-mediated bone destruction in periodontal disease.

    Science.gov (United States)

    Kajiya, Mikihito; Giro, Gabriela; Taubman, Martin A; Han, Xiaozhe; Mayer, Marcia P A; Kawai, Toshihisa

    2010-11-08

    Accumulated lines of evidence suggest that hyperimmune responses to periodontal bacteria result in the destruction of periodontal connective tissue and alveolar bone. The etiological roles of periodontal bacteria in the onset and progression of periodontal disease (PD) are well documented. However, the mechanism underlying the engagement of periodontal bacteria in RANKL-mediated alveolar bone resorption remains unclear. Therefore, this review article addresses three critical subjects. First, we discuss earlier studies of immune intervention, ultimately leading to the identification of bacteria-reactive lymphocytes as the cellular source of osteoclast-induction factor lymphokine (now called RANKL) in the context of periodontal bone resorption. Next, we consider (1) the effects of periodontal bacteria on RANKL production from a variety of adaptive immune effector cells, as well as fibroblasts, in inflamed periodontal tissue and (2) the bifunctional roles (upregulation vs. downregulation) of LPS produced from periodontal bacteria in a RANKL-induced osteoclast-signal pathway. Future studies in these two areas could lead to new therapeutic approaches for the management of PD by down-modulating RANKL production and/or RANKL-mediated osteoclastogenesis in the context of host immune responses against periodontal pathogenic bacteria.

  12. Experimental study on transferring pEGFP into mice facial nerve by ultrasound-mediated microbubbles%超声微泡对pEGFP质粒转染小鼠损伤面神经的促进作用

    Institute of Scientific and Technical Information of China (English)

    王丹; 骆文龙

    2011-01-01

    scanning confocal microscope(LSCM) and western blot.Meanwhile,green fluorescent was observed in the mice' s brainstem by LSCM.Results:The expression of pEGFP was the strongest in Ultrasound+ Microbubbles+ pEGFP group,followed by lipofectamineTM 2000+pEGFP group,Ultrasound+pEGFP group,Microbubbles+pEGFP group,pEGFP only treatment group and surgery only group.The differences between any two groups were statistically significant(P0.05).While pEGFP had not been detected in the mice' s brainstem yet.Conclusion:Ultrasound-mediated microbubble destruction could improve the transfection of pEFGP in injury facial nerve trunks safely.

  13. Suppressor of cytokine signalling-3 expression inhibits cytokine-mediated destruction of primary mouse and rat pancreatic islets and delays allograft rejection

    DEFF Research Database (Denmark)

    Rønn, S G; Börjesson, A; Bruun, C

    2008-01-01

    The pro-inflammatory cytokines IL-1 and IFNgamma are critical molecules in immune-mediated beta cell destruction leading to type 1 diabetes mellitus. Suppressor of cytokine signalling (SOCS)-3 inhibits the cytokine-mediated destruction of insulinoma-1 cells. Here we investigate the effect of SOCS...

  14. Microbubble Cavitation Imaging

    OpenAIRE

    Vignon, Francois; Shi, William T.; Powers, Jeffry E.; Everbach, E. Carr; Liu, Jinjin; Gao, Shunji; Xie, Feng; Porter, Thomas R.

    2013-01-01

    Ultrasound cavitation of microbubble contrast agents has a potential for therapeutic applications such as sonothrombolysis (STL) in acute ischemic stroke. For safety, efficacy, and reproducibility of treatment, it is critical to evaluate the cavitation state (moderate oscillations, stable cavitation, and inertial cavitation) and activity level in and around a treatment area. Acoustic passive cavitation detectors (PCDs) have been used to this end but do not provide spatial information.

  15. Microbubble Cavitation Imaging

    Science.gov (United States)

    Vignon, Francois; Shi, William T.; Powers, Jeffry E.; Everbach, E. Carr; Liu, Jinjin; Gao, Shunji; Xie, Feng; Porter, Thomas R.

    2014-01-01

    Ultrasound cavitation of microbubble contrast agents has a potential for therapeutic applications such as sonothrombolysis (STL) in acute ischemic stroke. For safety, efficacy, and reproducibility of treatment, it is critical to evaluate the cavitation state (moderate oscillations, stable cavitation, and inertial cavitation) and activity level in and around a treatment area. Acoustic passive cavitation detectors (PCDs) have been used to this end but do not provide spatial information. This paper presents a prototype of a 2-D cavitation imager capable of producing images of the dominant cavitation state and activity level in a region of interest. Similar to PCDs, the cavitation imaging described here is based on the spectral analysis of the acoustic signal radiated by the cavitating microbubbles: ultraharmonics of the excitation frequency indicate stable cavitation, whereas elevated noise bands indicate inertial cavitation; the absence of both indicates moderate oscillations. The prototype system is a modified commercially available ultrasound scanner with a sector imaging probe. The lateral resolution of the system is 1.5 mm at a focal depth of 3 cm, and the axial resolution is 3 cm for a therapy pulse length of 20 µs. The maximum frame rate of the prototype is 2 Hz. The system has been used for assessing and mapping the relative importance of the different cavitation states of a microbubble contrast agent. In vitro (tissue-mimicking flow phantom) and in vivo (heart, liver, and brain of two swine) results for cavitation states and their changes as a function of acoustic amplitude are presented. PMID:23549527

  16. Prophage-mediated dynamics of 'Candidatus Liberibacter asiaticus' populations, the destructive bacterial pathogens of citrus huanglongbing.

    Directory of Open Access Journals (Sweden)

    Lijuan Zhou

    Full Text Available Prophages are highly dynamic components in the bacterial genome and play an important role in intraspecies variations. There are at least two prophages in the chromosomes of Candidatus Liberibacter asiaticus' (Las Floridian isolates. Las is both unculturable and the most prevalent species of Liberibacter pathogens that cause huanglongbing (HLB, a worldwide destructive disease of citrus. In this study, seven new prophage variants resulting from two hyper-variable regions were identified by screening clone libraries of infected citrus, periwinkle and psyllids. Among them, Types A and B share highly conserved sequences and localize within the two prophages, FP1 and FP2, respectively. Although Types B and C were abundant in all three libraries, Type A was much more abundant in the libraries from the Las-infected psyllids than from the Las-infected plants, and Type D was only identified in libraries from the infected host plants but not from the infected psyllids. Sequence analysis of these variants revealed that the variations may result from recombination and rearrangement events. Conventional PCR results using type-specific molecular markers indicated that A, B, C and D are the four most abundant types in Las-infected citrus and periwinkle. However, only three types, A, B and C are abundant in Las-infected psyllids. Typing results for Las-infected citrus field samples indicated that mixed populations of Las bacteria present in Floridian isolates, but only the Type D population was correlated with the blotchy mottle symptom. Extended cloning and sequencing of the Type D region revealed a third prophage/phage in the Las genome, which may derive from the recombination of FP1 and FP2. Dramatic variations in these prophage regions were also found among the global Las isolates. These results are the first to demonstrate the prophage/phage-mediated dynamics of Las populations in plant and insect hosts, and their correlation with insect transmission and

  17. Prophage-mediated dynamics of 'Candidatus Liberibacter asiaticus' populations, the destructive bacterial pathogens of citrus huanglongbing.

    Science.gov (United States)

    Zhou, Lijuan; Powell, Charles A; Li, Wenbin; Irey, Mike; Duan, Yongping

    2013-01-01

    Prophages are highly dynamic components in the bacterial genome and play an important role in intraspecies variations. There are at least two prophages in the chromosomes of Candidatus Liberibacter asiaticus' (Las) Floridian isolates. Las is both unculturable and the most prevalent species of Liberibacter pathogens that cause huanglongbing (HLB), a worldwide destructive disease of citrus. In this study, seven new prophage variants resulting from two hyper-variable regions were identified by screening clone libraries of infected citrus, periwinkle and psyllids. Among them, Types A and B share highly conserved sequences and localize within the two prophages, FP1 and FP2, respectively. Although Types B and C were abundant in all three libraries, Type A was much more abundant in the libraries from the Las-infected psyllids than from the Las-infected plants, and Type D was only identified in libraries from the infected host plants but not from the infected psyllids. Sequence analysis of these variants revealed that the variations may result from recombination and rearrangement events. Conventional PCR results using type-specific molecular markers indicated that A, B, C and D are the four most abundant types in Las-infected citrus and periwinkle. However, only three types, A, B and C are abundant in Las-infected psyllids. Typing results for Las-infected citrus field samples indicated that mixed populations of Las bacteria present in Floridian isolates, but only the Type D population was correlated with the blotchy mottle symptom. Extended cloning and sequencing of the Type D region revealed a third prophage/phage in the Las genome, which may derive from the recombination of FP1 and FP2. Dramatic variations in these prophage regions were also found among the global Las isolates. These results are the first to demonstrate the prophage/phage-mediated dynamics of Las populations in plant and insect hosts, and their correlation with insect transmission and disease development.

  18. Tanscranial Threshold of Inertial Cavitation Induced by Diagnosticc Ultrasound and Microbubbles

    NARCIS (Netherlands)

    Liu, J.; Gao, S.; Porter, T.R.; Everbach, C; Shi, W.; Vignon, F.; Powers, J.; Lof, J.; Turner, J.; Xie, F.

    2011-01-01

    Background: Inertial cavitation may cause hazardous bioeffects whileusing ultrasound and microbubble mediated thrombolysis. The purposeof this study was to investigate the influence of ultrasound pulselength and temporal bone on inertial cavitation thresholds within the brain utilizing transtemporal

  19. Nerve growth factor delivery by ultrasound-mediated nanobubble destruction as a treatment for acute spinal cord injury in rats

    Science.gov (United States)

    Song, Zhaojun; Wang, Zhigang; Shen, Jieliang; Xu, Shengxi; Hu, Zhenming

    2017-01-01

    Background Spinal cord injuries (SCIs) can cause severe disability or death. Treatment options include surgical intervention, drug therapy, and stem cell transplantation. However, the efficacy of these methods for functional recovery remains unsatisfactory. Purpose This study was conducted to explore the effect of ultrasound (US)-mediated destruction of poly(lactic-co-glycolic acid) (PLGA) nanobubbles (NBs) expressing nerve growth factor (NGF) (NGF/PLGA NBs) on nerve regeneration in rats following SCI. Materials and methods Adult male Sprague Dawley rats were randomly divided into four treatment groups after Allen hit models of SCI were established. The groups were normal saline (NS) group, NGF and NBs group, NGF and US group, and NGF/PLGA NBs and US group. Histological changes after SCI were observed by hematoxylin and eosin staining. Neuron viability was determined by Nissl staining. Terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling staining was used to examine cell apoptosis. NGF gene and protein expressions were detected by quantitative reverse transcription polymerase chain reaction and Western blotting. Green fluorescent protein expression in the spinal cord was examined using an inverted fluorescence microscope. The recovery of neural function was determined using the Basso, Beattie, and Bresnahan test. Results NGF therapy using US-mediated NGF/PLGA NBs destruction significantly increased NGF expression, attenuated histological injury, decreased neuron loss, inhibited neuronal apoptosis in injured spinal cords, and increased BBB scores in rats with SCI. Conclusion US-mediated NGF/PLGA NBs destruction effectively transfects the NGF gene into target tissues and has a significant effect on the injured spinal cord. The combination of US irradiation and gene therapy through NGF/PLGA NBs holds great promise for the future of nanomedicine and the development of noninvasive treatment options for SCI and other diseases. PMID:28280337

  20. Microbubble responses to a similar mechanical index with different real-time perfusion imaging techniques.

    Science.gov (United States)

    Porter, Thomas R; Oberdorfer, Joseph; Rafter, Patrick; Lof, John; Xie, Feng

    2003-08-01

    The purpose of this study was to determine differences in contrast enhancement and microbubble destruction rates with current commercially available low-mechanical index (MI) real-time perfusion imaging modalities. A tissue-mimicking phantom was developed that had vessels at 3 cm (near field) and 9 cm (far field) from a real-time transducer. Perfluorocarbon-exposed sonicated dextrose albumin microbubbles (PESDA) were injected proximal to a mixing chamber, and then passed through these vessels while the region was insonified with either pulses of alternating polarity with pulse inversion Doppler (PID) or pulses of alternating amplitude by power modulation (PM) at MIs of 0.1, 0.2 and 0.3. Effluent microbubble concentration, contrast intensity and the slope of digital contrast intensity vs. time were measured. Our results demonstrated that microbubble destruction already occurs with PID at an MI of 0.1. Contrast intensity seen with PID was less than with PM. Therefore, differences in contrast enhancement and microbubble destruction rates occur at a similar MI setting when using different real-time pulse sequence schemes.

  1. Hyper-inflammation and skin destruction mediated by rosiglitazone activation of macrophages in IL-6 deficiency

    DEFF Research Database (Denmark)

    Das, Lopa M; Rosenjack, Julie; Au, Liemin

    2015-01-01

    Injury initiates recruitment of macrophages to support tissue repair; however, excessive macrophage activity may exacerbate tissue damage causing further destruction and subsequent delay in wound repair. Here we show that the peroxisome proliferation-activated receptor-γ agonist, rosiglitazone (R...

  2. Injustice and employees' destructive responses: The mediating role of of state negative affect

    NARCIS (Netherlands)

    Van Yperen, N.W.; Hagedoorn, M.; Zweers, Michiel; Postma, Saapke

    2000-01-01

    The focus of this study was employees' destructive behavioral intentions (i.e., exit, neglect, and aggressive voice) as a result of perceived injustice. In order to get an indication of the generalizability of the results, two studies employing different methodologies were conducted among different

  3. Ultrafast 2-dimensional image monitoring and array-based passive cavitation detection for ultrasound contrast agent destruction in a variably sized region.

    Science.gov (United States)

    Xu, Shanshan; Hu, Hong; Jiang, Hujie; Xu, Zhi'an; Wan, Mingxi

    2014-11-01

    A combined approach was proposed, based on programmable ultrasound equipment, to simultaneously monitor surviving microbubbles and detect cavitation activity during microbubble destruction in a variably sized region for use in ultrasound contrast agent (UCA)-enhanced therapeutic ultrasound applications. A variably sized focal region wherein the acoustic pressure was above the UCA fragmentation threshold was synthesized at frequencies of 3, 4, 5, and 6 MHz with a linear broadband imaging probe. The UCAs' temporal and spatial distribution during the microbubbles' destruction was monitored in a 2-dimensional imaging plane at 5 MHz and a frame rate of 400 Hz, and simultaneously, broadband noise emissions during the microbubbles' fragmentation were extracted by using the backscattered signals produced by the focused release bursts (ie, destruction pulses) themselves. Afterward, the temporal evolution of broadband noise emission, the surviving microbubbles in a region of interest (ROI), and the destruction area in a static UCA suspension were computed. Then the inertial cavitation dose, destruction rate of microbubbles in the ROI, and area of the destruction region were determined. It was found that an increasing pulse length and a decreasing transmit aperture and excitation frequency were correlated with an increased inertial cavitation dose, microbubble destruction rate, and destruction area. Furthermore, it was obvious that the microbubble destruction rate was significantly correlated with the inertial cavitation dose (P cavitation dose could be regulated by manipulating the transmission parameters. © 2014 by the American Institute of Ultrasound in Medicine.

  4. Spark channel propagation in a microbubble liquid

    Energy Technology Data Exchange (ETDEWEB)

    Panov, V. A.; Vasilyak, L. M., E-mail: vasilyak@ihed.ras.ru; Vetchinin, S. P.; Pecherkin, V. Ya.; Son, E. E. [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation)

    2016-11-15

    Experimental study on the development of the spark channel from the anode needle under pulsed electrical breakdown of isopropyl alcohol solution in water with air microbubbles has been performed. The presence of the microbubbles increases the velocity of the spark channel propagation and increases the current in the discharge gap circuit. The observed rate of spark channel propagation in microbubble liquid ranges from 4 to 12 m/s, indicating the thermal mechanism of the spark channel development in a microbubble liquid.

  5. Host tissue destruction by Entamoeba histolytica: molecules mediating adhesion, cytolysis, and proteolysis

    Directory of Open Access Journals (Sweden)

    Rolf D. Horstmann

    1992-01-01

    Full Text Available Entamoeba histolytica, the protozoan parasite causing human amoebisis, has recently been found to comprise two genetically distinct forms, potentially pathogenic and constitutively nonpathogenic ones. Host tissue destruction by pathogenic forms is belived to result from cell functions mediaed by a lectin-type adherence receptor, a pore-forming peptide involved in host cell lysis, and abundant expression of cysteine proteinase(s. Isolation and molecular cloning of these amoeba products have provided the tools for structural analyses and manipulations of cell functions including comparisons between pathogenic and nonpathogenic forms.

  6. Correlation between microbubble-induced acoustic cavitation and hemolysis in vitro

    International Nuclear Information System (INIS)

    Zhang Chun-Bing; Liu Zheng; Guo Xia-Sheng; Zhang Dong

    2011-01-01

    Microbubbles promise to enhance the efficiency of ultrasound-mediated drug delivery and gene therapy by taking advantage of artificial cavitation nuclei. The purpose of this study is to examine the ultrasound-induced hemolysis in the application of drug delivery in the presence of microbubbles. To achieve this goal, human red blood cells mixed with microbubbles were exposed to 1-MHz pulsed ultrasound. The hemolysis level was measured by a flow cytometry, and the cavitation dose was detected by a passive cavitation detecting system. The results demonstrate that larger cavitation dose would be generated with the increase of acoustic pressure, which might give rise to the enhancement of hemolysis. Besides the experimental observations, the acoustic pressure dependence of the radial oscillation of microbubble was theoretically estimated. The comparison between the experimental and calculation results indicates that the hemolysis should be highly correlated to the acoustic cavitation. (classical areas of phenomenology)

  7. Collective dissolution of microbubbles

    Science.gov (United States)

    Michelin, Sébastien; Guérin, Etienne; Lauga, Eric

    2018-04-01

    A microscopic bubble of soluble gas always dissolves in finite time in an undersaturated fluid. This diffusive process is driven by the difference between the gas concentration near the bubble, whose value is governed by the internal pressure through Henry's law, and the concentration in the far field. The presence of neighboring bubbles can significantly slow down this process by increasing the effective background concentration and reducing the diffusing flux of dissolved gas experienced by each bubble. We develop theoretical modeling of such diffusive shielding process in the case of small microbubbles whose internal pressure is dominated by Laplace pressure. We first use an exact semianalytical solution to capture the case of two bubbles and analyze in detail the shielding effect as a function of the distance between the bubbles and their size ratio. While we also solve exactly for the Stokes flow around the bubble, we show that hydrodynamic effects are mostly negligible except in the case of almost-touching bubbles. In order to tackle the case of multiple bubbles, we then derive and validate two analytical approximate yet generic frameworks, first using the method of reflections and then by proposing a self-consistent continuum description. Using both modeling frameworks, we examine the dissolution of regular one-, two-, and three-dimensional bubble lattices. Bubbles located at the edge of the lattices dissolve first, while innermost bubbles benefit from the diffusive shielding effect, leading to the inward propagation of a dissolution front within the lattice. We show that diffusive shielding leads to severalfold increases in the dissolution time, which grows logarithmically with the number of bubbles in one-dimensional lattices and algebraically in two and three dimensions, scaling respectively as its square root and 2 /3 power. We further illustrate the sensitivity of the dissolution patterns to initial fluctuations in bubble size or arrangement in the case

  8. Microbubble acoustic signatures: bubble deflation

    NARCIS (Netherlands)

    ten Brinke, G.A.; Slump, Cornelis H.

    2006-01-01

    Ultrasound Contrast Agents (UCAs) are used in medical imaging to enhance the visibility of structures, especially blood vessels and the liver. An example application of UCAs is the detection and classification of tumors. The most common UCA consist of microbubbles, which have pronounced non-linear

  9. Ultrasound Contrast Agent Microbubble Dynamics

    NARCIS (Netherlands)

    Overvelde, M.L.J.; Vos, Henk; de Jong, N.; Versluis, Michel; Paradossi, Gaio; Pellegretti, Paolo; Trucco, Andrea

    2010-01-01

    Ultrasound contrast agents are traditionally used in ultrasound-assisted organ perfusion imaging. Recently the use of coated microbubbles has been proposed for molecular imaging applications where the bubbles are covered with a layer of targeting ligands to bind specifically to their target cells.

  10. A type III-B CRISPR-Cas effector complex mediating massive target DNA destruction.

    Science.gov (United States)

    Han, Wenyuan; Li, Yingjun; Deng, Ling; Feng, Mingxia; Peng, Wenfang; Hallstrøm, Søren; Zhang, Jing; Peng, Nan; Liang, Yun Xiang; White, Malcolm F; She, Qunxin

    2017-02-28

    The CRISPR (clustered regularly interspaced short palindromic repeats) system protects archaea and bacteria by eliminating nucleic acid invaders in a crRNA-guided manner. The Sulfolobus islandicus type III-B Cmr-α system targets invading nucleic acid at both RNA and DNA levels and DNA targeting relies on the directional transcription of the protospacer in vivo. To gain further insight into the involved mechanism, we purified a native effector complex of III-B Cmr-α from S. islandicus and characterized it in vitro. Cmr-α cleaved RNAs complementary to crRNA present in the complex and its ssDNA destruction activity was activated by target RNA. The ssDNA cleavage required mismatches between the 5΄-tag of crRNA and the 3΄-flanking region of target RNA. An invader plasmid assay showed that mutation either in the histidine-aspartate acid (HD) domain (a quadruple mutation) or in the GGDD motif of the Cmr-2α protein resulted in attenuation of the DNA interference in vivo. However, double mutation of the HD motif only abolished the DNase activity in vitro. Furthermore, the activated Cmr-α binary complex functioned as a highly active DNase to destroy a large excess DNA substrate, which could provide a powerful means to rapidly degrade replicating viral DNA. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

  11. CTL escape mediated by proteasomal destruction of an HIV-1 cryptic epitope.

    Directory of Open Access Journals (Sweden)

    Sylvain Cardinaud

    2011-05-01

    Full Text Available Cytotoxic CD8+ T cells (CTLs play a critical role in controlling viral infections. HIV-infected individuals develop CTL responses against epitopes derived from viral proteins, but also against cryptic epitopes encoded by viral alternative reading frames (ARF. We studied here the mechanisms of HIV-1 escape from CTLs targeting one such cryptic epitope, Q9VF, encoded by an HIVgag ARF and presented by HLA-B*07. Using PBMCs of HIV-infected patients, we first cloned and sequenced proviral DNA encoding for Q9VF. We identified several polymorphisms with a minority of proviruses encoding at position 5 an aspartic acid (Q9VF/5D and a majority encoding an asparagine (Q9VF/5N. We compared the prevalence of each variant in PBMCs of HLA-B*07+ and HLA-B*07- patients. Proviruses encoding Q9VF/5D were significantly less represented in HLA-B*07+ than in HLA-B*07- patients, suggesting that Q9FV/5D encoding viruses might be under selective pressure in HLA-B*07+ individuals. We thus analyzed ex vivo CTL responses directed against Q9VF/5D and Q9VF/5N. Around 16% of HLA-B*07+ patients exhibited CTL responses targeting Q9VF epitopes. The frequency and the magnitude of CTL responses induced with Q9VF/5D or Q9VF/5N peptides were almost equal indicating a possible cross-reactivity of the same CTLs on the two peptides. We then dissected the cellular mechanisms involved in the presentation of Q9VF variants. As expected, cells infected with HIV strains encoding for Q9VF/5D were recognized by Q9VF/5D-specific CTLs. In contrast, Q9VF/5N-encoding strains were neither recognized by Q9VF/5N- nor by Q9VF/5D-specific CTLs. Using in vitro proteasomal digestions and MS/MS analysis, we demonstrate that the 5N variation introduces a strong proteasomal cleavage site within the epitope, leading to a dramatic reduction of Q9VF epitope production. Our results strongly suggest that HIV-1 escapes CTL surveillance by introducing mutations leading to HIV ARF-epitope destruction by proteasomes.

  12. Destruction of hazardous and mixed wastes using mediated electrochemical oxidation in a Ag(II)HNO3 bench scale system

    International Nuclear Information System (INIS)

    Balazs, B.; Chiba, Z.; Hsu, P.; Lewis, P.; Murguia, L.; Adamson, M.

    1997-01-01

    Mediated Electrochemical Oxidation (MEO) is a promising technology for the destruction of organic containing wastes and the remediation of mixed wastes containing transuranic components. The combination of a powerful oxidant and an acid solution allows the conversion of nearly all organics, whether present in hazardous or in mixed waste, to carbon dioxide. Insoluble transuranics are dissolved in this process and may be recovered by separation and precipitation.The MEO technique offers several advantages which are inherent in the system. First, the oxidation/dissolution processes are accomplished at near ambient pressures and temperatures (30-70 degrees C). Second, all waste stream components and oxidation products (with the exception of evolved gases) are contained in an aqueous environment. This electrolyte acts as an accumulator for inorganics which were present in the original waste stream, and the large volume of electrolyte provides a thermal buffer for the energy released during oxidation of the organics. Third, the generation of secondary waste is minimal, as the process needs no additional reagents. Finally, the entire process can be shut down by simply turning off the power, affording a level of control unavailable in some other techniques.Numerous groups, both in the United States and Europe, have made substantial progress in the last decade towards understanding the mechanistic pathways, kinetics, and engineering aspects of the process. At Lawrence Livermore National Laboratory, substantial contributions have been made to this knowledge base in these areas and others. Conceptual design and engineering development have been completed for a pilot plant-scale MEO system, and numerous data have been gathered on the efficacy of the process for a wide variety of anticipated waste components. This presentation will review the data collected at LLNL for a bench scale system based primarily on the use of a Ag(II) mediator in a nitric acid electrolyte; results

  13. Rapid Evaporation of microbubbles

    Science.gov (United States)

    Gautam, Jitendra; Esmaeeli, Asghar

    2008-11-01

    When a liquid is heated to a temperature far above its boiling point, it evaporates abruptly. Boiling of liquid at high temperatures can be explosive and destructive, and poses a potential hazard for a host of industrial processes. Explosive boiling may occur if a cold and volatile liquid is brought into contact with a hot and non-volatile liquid, or if a liquid is superheated or depressurized rapidly. Such possibilities are realized, for example, in the depressurization of low boiling point liquefied natural gas (LNG) in the pipelines or storage tanks as a result of a leak. While boiling of highly heated liquids can be destructive at macroscale, the (nearly) instantaneous pace of the process and the release of large amount of kinetic energy make the phenomena extremely attractive at microscale where it is possible to utilize the released energy to derive micromechanical systems. For instance, there is currently a growing interest in micro-explosion of liquid for generation of micro bubbles for actuation purposes. The aim of the current study is to gain a fundamental understanding of the subject using direct numerical simulations. In particular, we seek to investigate the boundary between stable and unstable nucleus growth in terms of the degree of liquid superheat and to compare the dynamics of unstable and stable growth.

  14. Microbubble smallness limited by conjunctions

    Czech Academy of Sciences Publication Activity Database

    Tesař, Václav

    Roč. 231, September (2013), s. 526-536 ISSN 1385-8947 R&D Projects: GA ČR GA13-23046S Institutional research plan: CEZ:AV0Z20760514 Institutional support: RVO:61388998 Keywords : bubbles * microbubbles * bubble coalescence Subject RIV: BK - Fluid Dynamics Impact factor: 4.058, year: 2013 http://dx.doi.org/10.1016/j.cej.2013.06.051

  15. Collapse dynamics of ultrasound contrast agent microbubbles

    Science.gov (United States)

    King, Daniel Alan

    Ultrasound contrast agents (UCAs) are micron-sized gas bubbles encapsulated with thin shells on the order of nanometers thick. The damping effects of these viscoelastic coatings are widely known to significantly alter the bubble dynamics for linear and low-amplitude behavior; however, their effects on strongly nonlinear and destruction responses are much less studied. This dissertation examines the behaviors of single collapsing shelled microbubbles using experimental and theoretical methods. The study of their dynamics is particularly relevant for emerging experimental uses of UCAs which seek to leverage localized mechanical forces to create or avoid specialized biomedical effects. The central component in this work is the study of postexcitation rebound and collapse, observed acoustically to identify shell rupture and transient inertial cavitation of single UCA microbubbles. This time-domain analysis of the acoustic response provides a unique method for characterization of UCA destruction dynamics. The research contains a systematic documentation of single bubble postexcitation collapse through experimental measurement with the double passive cavitation detection (PCD) system at frequencies ranging from 0.9 to 7.1 MHz and peak rarefactional pressure amplitudes (PRPA) ranging from 230 kPa to 6.37 MPa. The double PCD setup is shown to improve the quality of collected data over previous setups by allowing symmetric responses from a localized confocal region to be identified. Postexcitation signal percentages are shown to generally follow trends consistent with other similar cavitation metrics such as inertial cavitation, with greater destruction observed at both increased PRPA and lower frequency over the tested ranges. Two different types of commercially available UCAs are characterized and found to have very different collapse thresholds; lipid-shelled Definity exhibits greater postexcitation at lower PRPAs than albumin-shelled Optison. Furthermore, by altering

  16. Usage of CO2 microbubbles as flow-tracing contrast media in X-ray dynamic imaging of blood flows.

    Science.gov (United States)

    Lee, Sang Joon; Park, Han Wook; Jung, Sung Yong

    2014-09-01

    X-ray imaging techniques have been employed to visualize various biofluid flow phenomena in a non-destructive manner. X-ray particle image velocimetry (PIV) was developed to measure velocity fields of blood flows to obtain hemodynamic information. A time-resolved X-ray PIV technique that is capable of measuring the velocity fields of blood flows under real physiological conditions was recently developed. However, technical limitations still remained in the measurement of blood flows with high image contrast and sufficient biocapability. In this study, CO2 microbubbles as flow-tracing contrast media for X-ray PIV measurements of biofluid flows was developed. Human serum albumin and CO2 gas were mechanically agitated to fabricate CO2 microbubbles. The optimal fabricating conditions of CO2 microbubbles were found by comparing the size and amount of microbubbles fabricated under various operating conditions. The average size and quantity of CO2 microbubbles were measured by using a synchrotron X-ray imaging technique with a high spatial resolution. The quantity and size of the fabricated microbubbles decrease with increasing speed and operation time of the mechanical agitation. The feasibility of CO2 microbubbles as a flow-tracing contrast media was checked for a 40% hematocrit blood flow. Particle images of the blood flow were consecutively captured by the time-resolved X-ray PIV system to obtain velocity field information of the flow. The experimental results were compared with a theoretically amassed velocity profile. Results show that the CO2 microbubbles can be used as effective flow-tracing contrast media in X-ray PIV experiments.

  17. SCFβ-TRCP targets MTSS1 for ubiquitination-mediated destruction to regulate cancer cell proliferation and migration

    Science.gov (United States)

    Tron, Adriana E.; Wang, Zhiwei; Sun, Liankun; Inuzuka, Hiroyuki; Wei, Wenyi

    2013-01-01

    Metastasis suppressor 1 (MTSS1) is an important tumor suppressor protein, and loss of MTSS1 expression has been observed in several types of human cancers. Importantly, decreased MTSS1 expression is associated with more aggressive forms of breast and prostate cancers, and with poor survival rate. Currently, it remains unclear how MTSS1 is regulated in cancer cells, and whether reduced MTSS1 expression contributes to elevated cancer cell proliferation and migration. Here we report that the SCFβ-TRCP regulates MTSS1 protein stability by targeting it for ubiquitination and subsequent destruction via the 26S proteasome. Notably, depletion of either Cullin 1 or β-TRCP1 led to increased levels of MTSS1. We further demonstrated a crucial role for Ser322 in the DSGXXS degron of MTSS1 in governing SCFβ-TRCP-mediated MTSS1 degradation. Mechanistically, we defined that Casein Kinase Iδ (CKIδ) phosphorylates Ser322 to trigger MTSS1's interaction with β-TRCP for subsequent ubiquitination and degradation. Importantly, introducing wild-type MTSS1 or a non-degradable MTSS1 (S322A) into breast or prostate cancer cells with low MTSS1 expression significantly inhibited cellular proliferation and migration. Moreover, S322A-MTSS1 exhibited stronger effects in inhibiting cell proliferation and migration when compared to ectopic expression of wild-type MTSS1. Therefore, our study provides a novel molecular mechanism for the negative regulation of MTSS1 by β-TRCP in cancer cells. It further suggests that preventing MTSS1 degradation could be a possible novel strategy for clinical treatment of more aggressive breast and prostate cancers. PMID:24318128

  18. PBCA-based polymeric microbubbles for molecular imaging and drug delivery

    NARCIS (Netherlands)

    Koczera, Patrick; Appold, Lia; Shi, Yang; Liu, Mengjiao; Dasgupta, Anshuman; Pathak, Vertika; Ojha, Tarun; Fokong, Stanley; Wu, Zhuojun; Van Zandvoort, Marc; Iranzo, Olga; Kuehne, Alexander J C; Pich, Andrij; Kiessling, Fabian; Lammers, Twan

    2017-01-01

    Microbubbles (MB) are routinely used as contrast agents for ultrasound (US) imaging. We describe different types of targeted and drug-loaded poly(n-butyl cyanoacrylate) (PBCA) MB, and demonstrate their suitability for multiple biomedical applications, including molecular US imaging and US-mediated

  19. Image-guided, targeted and triggered drug delivery to tumors using polymer-based microbubbles.

    NARCIS (Netherlands)

    Fokong, S.; Theek, B.; Koczera, P.; Appold, L.; Resch-Genger, U.; van Zandvoort, M.; Storm, Gerrit; Kiessling, F.; Lammers, Twan Gerardus Gertudis Maria

    2012-01-01

    Abstract Microbubbles (MB) are routinely used contrast agents for functional and molecular ultrasound (US) imaging. In addition, they have been attracting more and more attention for drug delivery purposes, enabling e.g. US-mediated drug delivery across biological barriers and US-induced triggered

  20. Are microbubbles free flowing tracers through the Myocardium? Comparison of indicator-dilution curves obtained from dye dilution and echo contrast using harmonic power Doppler imaging.

    Science.gov (United States)

    Tiemann, K; Schlosser, T; Pohl, C; Bimmel, D; Wietasch, G; Hoeft, A; Likungu, J; Vahlhaus, C; Kuntz, S; Nanda, N C; Becher, H; Lüderitz, B

    2000-01-01

    Harmonic power Doppler imaging (H-PDI) has been introduced into the field of contrast echocardiography as a contrast-specific imaging modality. However, there has been considerable skepticism as to whether H-PDI would be quantifiable, because it depends on the destruction of microbubbles and has more complex signal processing than gray scale imaging. The aim of the present study was to evaluate the relationship between the concentration of microbubbles and the resulting H-PDI signals even under conditions where bubble destruction is most likely. Furthermore, we evaluated whether microbubbles of Levovist freely pass the microcirculation, which is a prerequisite for the assessment of myocardial blood flow. A strong positive correlation was found between the H-PDI signals and the amount of microbubbles up to the onset of acoustic shadowing (r = 0. 968, Pgreen (ICG) in both a flow phantom and a working heart setup. The mean transit times (MTTs) through the myocardium of both agents were compared after a bolus injection into the left coronary artery. A close correlation was observed between 1/MTT and flow in both setups (r>0.98, Pgreen. We conclude that microbubbles fulfill the prerequisites of free flowing tracers through the myocardium. Furthermore, H-PDI technology allows a reliable assessment of time-concentration curves of air-filled microbubbles up to the onset of acoustic shadowing.

  1. Experimental investigations of nonlinearities and destruction mechanisms of an experimental phospholipid-based ultrasound contrast agent.

    Science.gov (United States)

    Casciaro, Sergio; Palmizio Errico, Rosa; Errico, Rosa Palmizio; Conversano, Francesco; Demitri, Christian; Distante, Alessandro

    2007-02-01

    We sought to characterize the acoustical behavior of the experimental ultrasound contrast agent BR14 by determining the acoustic pressure threshold above which nonlinear oscillation becomes significant and investigating microbubble destruction mechanisms. We used a custom-designed in vitro setup to conduct broadband attenuation measurements at 3.5 MHz varying acoustic pressure (range, 50-190 kPa). We also performed granulometric analyses on contrast agent solutions to accurately measure microbubble size distribution and to evaluate insonification effects. Attenuation did not depend on acoustic pressure less than 100 kPa, indicating this pressure as the threshold for the appearance of microbubble nonlinear behavior. At the lowest excitation amplitude, attenuation increased during insonification, while, at higher excitation levels, the attenuation decreased over time, indicating microbubble destruction. The destruction rate changed with pressure amplitude suggesting different destruction mechanisms, as it was confirmed by granulometric analysis. Microbubbles showed a linear behavior until 100 kPa, whereas beyond this value significant nonlinearities occurred. Observed destruction phenomena seem to be mainly due to gas diffusion and bubble fragmentation mechanisms.

  2. Biosurfactants for Microbubble Preparation and Application

    OpenAIRE

    Takeo Shiina; Zengshe Liu; Mitsutoshi Nakajima; Qingyi Xu

    2011-01-01

    Biosurfactants can be classified by their chemical composition and their origin. This review briefly describes various classes of biosurfactants based on their origin and introduces a few of the most widely used biosurfactants. The current status and future trends in biosurfactant production are discussed, with an emphasis on those derived from plants. Following a brief introduction of the properties of microbubbles, recent progress in the application of microbubble technology to molecular im...

  3. Microbubble stability and applications in food

    OpenAIRE

    Rovers, T.A.M.

    2015-01-01

    Aeration of food is considered to be a good method to create a texture and mouthfeel of food products that is liked by the consumer. However, traditional foams are not stable for a prolonged time. Microbubbles are air bubbles covered with a shell that slows down disproportionation significantly and arrests coalescence. Protein stabilized microbubbles are seen as a promising new food ingredient for encapsulation, to replace fat, to create new textures, and to improve sensorial properties of fo...

  4. T Cell-Mediated Beta Cell Destruction: Autoimmunity and Alloimmunity in the Context of Type 1 Diabetes

    Directory of Open Access Journals (Sweden)

    Adam L. Burrack

    2017-12-01

    Full Text Available Type 1 diabetes (T1D results from destruction of pancreatic beta cells by T cells of the immune system. Despite improvements in insulin analogs and continuous blood glucose level monitoring, there is no cure for T1D, and some individuals develop life-threatening complications. Pancreas and islet transplantation have been attractive therapeutic approaches; however, transplants containing insulin-producing cells are vulnerable to both recurrent autoimmunity and conventional allograft rejection. Current immune suppression treatments subdue the immune system, but not without complications. Ideally a successful approach would target only the destructive immune cells and leave the remaining immune system intact to fight foreign pathogens. This review discusses the autoimmune diabetes disease process, diabetic complications that warrant a transplant, and alloimmunity. First, we describe the current understanding of autoimmune destruction of beta cells including the roles of CD4 and CD8 T cells and several possibilities for antigen-specific tolerance induction. Second, we outline diabetic complications necessitating beta cell replacement. Third, we discuss transplant recognition, potential sources for beta cell replacement, and tolerance-promoting therapies under development. We hypothesize that a better understanding of autoreactive T cell targets during disease pathogenesis and alloimmunity following transplant destruction could enhance attempts to re-establish tolerance to beta cells.

  5. Measurement of real pulsatile blood flow using X-ray PIV technique with CO2 microbubbles.

    Science.gov (United States)

    Park, Hanwook; Yeom, Eunseop; Seo, Seung-Jun; Lim, Jae-Hong; Lee, Sang-Joon

    2015-03-06

    Synchrotron X-ray imaging technique has been used to investigate biofluid flows in a non-destructive manner. This study aims to investigate the feasibility of the X-ray PIV technique with CO2 microbubbles as flow tracer for measurement of pulsatile blood flows under in vivo conditions. The traceability of CO2 microbubbles in a pulsatile flow was demonstrated through in vitro experiment. A rat extracorporeal bypass loop was used by connecting a tube between the abdominal aorta and jugular vein of a rat to obtain hemodynamic information of actual pulsatile blood flows without changing the hemorheological properties. The decrease in image contrast of the surrounding tissue was also investigated for in vivo applications of the proposed technique. This technique could be used to accurately measure whole velocity field information of real pulsatile blood flows and has strong potential for hemodynamic diagnosis of cardiovascular diseases.

  6. Measurement of real pulsatile blood flow using X-ray PIV technique with CO2 microbubbles

    Science.gov (United States)

    Park, Hanwook; Yeom, Eunseop; Seo, Seung-Jun; Lim, Jae-Hong; Lee, Sang-Joon

    2015-01-01

    Synchrotron X-ray imaging technique has been used to investigate biofluid flows in a non-destructive manner. This study aims to investigate the feasibility of the X-ray PIV technique with CO2 microbubbles as flow tracer for measurement of pulsatile blood flows under in vivo conditions. The traceability of CO2 microbubbles in a pulsatile flow was demonstrated through in vitro experiment. A rat extracorporeal bypass loop was used by connecting a tube between the abdominal aorta and jugular vein of a rat to obtain hemodynamic information of actual pulsatile blood flows without changing the hemorheological properties. The decrease in image contrast of the surrounding tissue was also investigated for in vivo applications of the proposed technique. This technique could be used to accurately measure whole velocity field information of real pulsatile blood flows and has strong potential for hemodynamic diagnosis of cardiovascular diseases. PMID:25744850

  7. Microbubble Distillation for Ethanol-Water Separation

    Directory of Open Access Journals (Sweden)

    Atheer Al-yaqoobi

    2016-01-01

    Full Text Available In the current study, a novel approach for separating ethanol-water mixture by microbubble distillation technology was investigated. Traditional distillation processes require large amounts of energy to raise the liquid to its boiling point to effect removal of volatile components. The concept of microbubble distillation by comparison is to heat the gas phase rather than the liquid phase to achieve separation. The removal of ethanol from the thermally sensitive fermentation broths was taken as a case of study. Consequently the results were then compared with those which could be obtained under equilibrium conditions expected in an “ideal” distillation unit. Microbubble distillation has achieved vapour compositions higher than that which could be obtained under traditional equilibrium conditions. The separation was achieved at liquid temperature significantly less than the boiling point of the mixture. In addition, it was observed that the separation efficiency of the microbubble distillation could be increased by raising the injected air temperature, while the temperature of the liquid mixture increased only moderately. The separation efficiency of microbubble distillation was compared with that of pervaporation for the recovery of bioethanol from the thermally sensitive fermentation broths. The technology could be controlled to give high separation and energy efficiency. This could contribute to improving commercial viability of biofuel production and other coproducts of biorefinery processing.

  8. Lead-silicate glass optical microbubble resonator

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Pengfei, E-mail: pengfei.wang@dit.ie [Photonics Research Centre, Dublin Institute of Technology, Kevin Street, Dublin 8 (Ireland); Optoelectronics Research Centre, University of Southampton, Southampton SO17 1BJ (United Kingdom); Ward, Jonathan; Yang, Yong; Chormaic, Síle Nic [Light-Matter Interactions Unit, OIST Graduate University, 1919-1 Tancha, Onna-son, Okinawa 904-0495 (Japan); Feng, Xian; Brambilla, Gilberto [Optoelectronics Research Centre, University of Southampton, Southampton SO17 1BJ (United Kingdom); Farrell, Gerald [Photonics Research Centre, Dublin Institute of Technology, Kevin Street, Dublin 8 (Ireland)

    2015-02-09

    Microbubble whispering gallery resonators have the potential to become key components in a variety of active and passive photonic circuit devices by offering a range of significant functionalities. Here, we report on the fabrication, optical characterization, and theoretical analysis of lead-silicate glass and optical microbubble resonators. Evanescent field coupling to the microbubbles was achieved using a 1 μm diameter, silica microfiber at a wavelength of circa 775 nm. High Q-factor modes were efficiently excited in both single-stem and two-stem, lead-silicate glass, and microbubble resonators, with bubble diameters of 38 μm (single-stem) and 48 μm (two-stem). Whispering gallery mode resonances with Q-factors as high as 2.3 × 10{sup 5} (single-stem) and 7 × 10{sup 6} (two-stem) were observed. By exploiting the high-nonlinearity of the lead-silicate glass, this work will act as a catalyst for studying a range of nonlinear optical effects in microbubbles, such as Raman scattering and four-wave mixing, at low optical powers.

  9. Cyclin B1 Destruction Box-Mediated Protein Instability: The Enhanced Sensitivity of Fluorescent-Protein-Based Reporter Gene System

    Directory of Open Access Journals (Sweden)

    Chao-Hsun Yang

    2013-01-01

    Full Text Available The periodic expression and destruction of several cyclins are the most important steps for the exact regulation of cell cycle. Cyclins are degraded by the ubiquitin-proteasome system during cell cycle. Besides, a short sequence near the N-terminal of cyclin B called the destruction box (D-box; CDB is also required. Fluorescent-protein-based reporter gene system is insensitive to analysis because of the overly stable fluorescent proteins. Therefore, in this study, we use human CDB fused with both enhanced green fluorescent protein (EGFP at C-terminus and red fluorescent protein (RFP, DsRed at N-terminus in the transfected human melanoma cells to examine the effects of CDB on different fluorescent proteins. Our results indicated that CDB-fused fluorescent protein can be used to examine the slight gene regulations in the reporter gene system and have the potential to be the system for screening of functional compounds in the future.

  10. Acoustically excited encapsulated microbubbles and mitigation of biofouling

    KAUST Repository

    Qamar, Adnan

    2017-08-31

    Provided herein is a universally applicable biofouling mitigation technology using acoustically excited encapsulated microbubbles that disrupt biofilm or biofilm formation. For example, a method of reducing biofilm formation or removing biofilm in a membrane filtration system is provided in which a feed solution comprising encapsulated microbubbles is provided to the membrane under conditions that allow the encapsulated microbubbles to embed in a biofilm. Sonication of the embedded, encapsulated microbubbles disrupts the biofilm. Thus, provided herein is a membrane filtration system for performing the methods and encapsulated microbubbles specifically selected for binding to extracellular polymeric substances (EFS) in a biofilm.

  11. Acoustic Studies on Nanodroplets, Microbubbles and Liposomes

    Science.gov (United States)

    Kumar, Krishna Nandan

    Microbubbles and droplets are nanometer to micron size biocompatible particles which are primarily used for drug delivery and contrast imaging. Our aim is to broaden the use of microbubbles from contrast imaging to other applications such as measuring blood pressure. The other goal is to develop in situ contrast agents (phase shift droplets) which can be used for applications such as cancer tumor imaging. Therefore, the focus is on developing and validating the concept using experimental and theoretical methods. Below is an overview of each of the projects performed on droplets and microbubbles. Phase shift droplets vaporizable by acoustic stimulation offer many advantages over microbubbles as contrast agents due to their higher stability and possibility of smaller sizes. In this study, the acoustic droplet vaporization (ADV) threshold of a suspension of PFP droplets (400-3000nm) was acoustically measured as a function of the excitation frequency by examining the scattered signals, fundamental, sub- and second-harmonic. This work presents the experimental methodology to determine ADV threshold. The threshold increases with frequency: 1.25 MPa at 2.25 MHz, 2.0 MPa at 5 MHz and 2.5 MPa at 10 MHz. The scattered response from droplets was also found to match well with that of independently prepared lipid-coated microbubble suspension in magnitude as well as trends above the threshold value. Additionally, we have employed classical nucleation theory (CNT) to investigate the ADV, specifically the threshold value of the peak negative pressure required for vaporization. The theoretical analysis predicts that the ADV threshold increases with increasing surface tension of the droplet core and frequency of excitation, while it decreases with increasing temperature and droplet size. The predictions are in qualitative agreement with experimental observations. A technique to measure the ambient pressure using microbubbles was developed. Here we are presenting the results of an

  12. Dynamics of micro-bubble sonication inside a phantom vessel

    KAUST Repository

    Qamar, Adnan; Samtaney, Ravi; Bull, Joseph L.

    2013-01-01

    A model for sonicated micro-bubble oscillations inside a phantom vessel is proposed. The model is not a variant of conventional Rayleigh-Plesset equation and is obtained from reduced Navier-Stokes equations. The model relates the micro-bubble oscillation dynamics with geometric and acoustic parameters in a consistent manner. It predicts micro-bubble oscillation dynamics as well as micro-bubble fragmentation when compared to the experimental data. For large micro-bubble radius to vessel diameter ratios, predictions are damped, suggesting breakdown of inherent modeling assumptions for these cases. Micro-bubble response with acoustic parameters is consistent with experiments and provides physical insight to the micro-bubble oscillation dynamics.

  13. Dynamics of micro-bubble sonication inside a phantom vessel

    KAUST Repository

    Qamar, Adnan

    2013-01-10

    A model for sonicated micro-bubble oscillations inside a phantom vessel is proposed. The model is not a variant of conventional Rayleigh-Plesset equation and is obtained from reduced Navier-Stokes equations. The model relates the micro-bubble oscillation dynamics with geometric and acoustic parameters in a consistent manner. It predicts micro-bubble oscillation dynamics as well as micro-bubble fragmentation when compared to the experimental data. For large micro-bubble radius to vessel diameter ratios, predictions are damped, suggesting breakdown of inherent modeling assumptions for these cases. Micro-bubble response with acoustic parameters is consistent with experiments and provides physical insight to the micro-bubble oscillation dynamics.

  14. Inertial cavitation threshold of nested microbubbles.

    Science.gov (United States)

    Wallace, N; Dicker, S; Lewin, Peter; Wrenn, S P

    2015-04-01

    Cavitation of ultrasound contrast agents (UCAs) promotes both beneficial and detrimental bioeffects in vivo (Radhakrishnan et al., 2013) [1]. The ability to determine the inertial cavitation threshold of UCA microbubbles has potential application in contrast imaging, development of therapeutic agents, and evaluation of localized effects on the body (Ammi et al., 2006) [2]. This study evaluates a novel UCA and its inertial cavitation behavior as determined by a home built cavitation detection system. Two 2.25 MHz transducers are placed at a 90° angle to one another where one transducer is driven by a high voltage pulser and the other transducer receives the signal from the oscillating microbubble. The sample chamber is placed in the overlap of the focal region of the two transducers where the microbubbles are exposed to a pulser signal consisting of 600 pulse trains per experiment at a pulse repetition frequency of 5 Hz where each train has four pulses of four cycles. The formulation being analyzed is comprised of an SF6 microbubble coated by a DSPC PEG-3000 monolayer nested within a poly-lactic acid (PLA) spherical shell. The effect of varying shell diameters and microbubble concentration on cavitation threshold profile for peak negative pressures ranging from 50 kPa to 2 MPa are presented and discussed in this paper. The nesting shell decreases inertial cavitation events from 97.96% for an un-nested microbubble to 19.09% for the same microbubbles nested within a 2.53 μm shell. As shell diameter decreases, the percentage of inertially cavitating microbubbles also decreases. For nesting formulations with average outer capsule diameters of 20.52, 14.95, 9.95, 5.55, 2.53, and 1.95 μm, the percentage of sample destroyed at 1 MPa was 51.02, 38.94, 33.25, 25.27, 19.09, and 5.37% respectively. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Microbubble stability and applications in food

    NARCIS (Netherlands)

    Rovers, T.A.M.

    2015-01-01

    Aeration of food is considered to be a good method to create a texture and mouthfeel of food products that is liked by the consumer. However, traditional foams are not stable for a prolonged time. Microbubbles are air bubbles covered with a shell that slows down disproportionation significantly

  16. Nonspherical oscilllations of ultrasound contrast agent microbubbles

    NARCIS (Netherlands)

    Dollet, B.; van der Meer, S.M.; Garbin, V.; Garbin, Valeria; de Jong, N.; Lohse, Detlef; Versluis, Michel

    2008-01-01

    The occurrence of nonspherical oscillations (or surface modes) of coated microbubbles, used as ultrasound contrast agents in medical imaging, is investigated using ultra–high-speed optical imaging. Optical tweezers designed to micromanipulate single bubbles in 3-D are used to trap the bubbles far

  17. Association schemes perspective of microbubble cluster in ultrasonic fields.

    Science.gov (United States)

    Behnia, S; Yahyavi, M; Habibpourbisafar, R

    2018-06-01

    Dynamics of a cluster of chaotic oscillators on a network are studied using coupled maps. By introducing the association schemes, we obtain coupling strength in the adjacency matrices form, which satisfies Markov matrices property. We remark that in general, the stability region of the cluster of oscillators at the synchronization state is characterized by Lyapunov exponent which can be defined based on the N-coupled map. As a detailed physical example, dynamics of microbubble cluster in an ultrasonic field are studied using coupled maps. Microbubble cluster dynamics have an indicative highly active nonlinear phenomenon, were not easy to be explained. In this paper, a cluster of microbubbles with a thin elastic shell based on the modified Keller-Herring equation in an ultrasonic field is demonstrated in the framework of the globally coupled map. On the other hand, a relation between the microbubble elements is replaced by a relation between the vertices. Based on this method, the stability region of microbubbles pulsations at complete synchronization state has been obtained analytically. In this way, distances between microbubbles as coupling strength play the crucial role. In the stability region, we thus observe that the problem of study of dynamics of N-microbubble oscillators reduce to that of a single microbubble. Therefore, the important parameters of the isolated microbubble such as applied pressure, driving frequency and the initial radius have effective behavior on the synchronization state. Copyright © 2018 Elsevier B.V. All rights reserved.

  18. Tunable microbubble generator using electrolysis and ultrasound

    OpenAIRE

    Younes Achaoui; Khaled Metwally; Damien Fouan; Zoubida Hammadi; Roger Morin; Eric Debieu; Cédric Payan; Serge Mensah

    2017-01-01

    This letter reports on a method for producing on demand calibrated bubbles in a non-chemically controlled solution using localized micro-electrolysis and ultrasound. Implementing a feedback loop in the process leads to a point source of stable mono-dispersed microbubbles. This approach overcomes the inertial constraints encountered in microfluidics with the possibility to produce from a single to an array of calibrated bubbles. Moreover, this method avoids the use of additional surfactant tha...

  19. Destructive distillation

    Energy Technology Data Exchange (ETDEWEB)

    Allison, C A

    1906-05-22

    The invention relates to an apparatus in which the destructive distillation or coking of coal, peat, shale, etc., is carried out by means of a current of hot gases at a temperature of 700--800/sup 0/F., as described in Specification No. 11,925, A.D. 1906.

  20. Facilitating Intracellular Drug Delivery by Ultrasound-Activated Microbubbles

    NARCIS (Netherlands)

    Lammertink, BHA

    2017-01-01

    The goal of this thesis was to investigate the combination of ultrasound and microbubbles (USMB) for intracellular delivery of (model) drugs in vitro. We have focused on clinically approved drugs, i.e. cisplatin, and microbubbles, i.e. SonoVue™, to facilitate clinical translation. In addition, model

  1. Destructive distillation

    Energy Technology Data Exchange (ETDEWEB)

    Cosden, S; Cosden, J S

    1937-09-08

    A means and process are described for the destructive distillation of solid carbonaceous materials in which the process comprises charging the material, in a finely divided condition into a stream of hot combustion gases, and allows the hot gases to act pyrolytically on the organic compounds contained in the material, separating the volatile liberated constituents from residuary constituents. Hot reaction gases are generated by fuel ignition means in a generator and are immediately intermingled with comminuted carbonaceous material from a hopper, in a narrow conduit. The mixture of material and reaction fluid is then passed through an elongated confined path, which is exteriorly heated by the combustion chamber of the furnace, where the destructive distillation is effected. Volatile and solid constituents are separated in the chamber, and the volatile constituents are fractionated and condensed.

  2. Ultrasound triggered drug delivery with liposomal nested microbubbles.

    Science.gov (United States)

    Wallace, N; Wrenn, S P

    2015-12-01

    When ultrasound contrast agent microbubbles are nested within a liposome, damage to the liposome membrane caused by both stable and inertial cavitation of the microbubble allows for release of the aqueous core of the liposome. Triggered release was not accomplished unless microbubbles were present within the liposome. Leakage was tested using fluorescence assays developed specifically for this drug delivery vehicle and qualitative measurements using an optical microscope. These studies were done using a 1 MHz focused ultrasound transducer while varying parameters including peak negative ultrasound pressure, average liposome diameter, and microbubble concentration. Two regimes exist for membrane disruption caused by cavitating microbubbles. A faster release rate, as well as permanent membrane damage are seen for samples exposed to high pressure (2.1-3.7 MPa). A slower release rate and dilation/temporary poration are characteristic of stable cavitation for low pressure studies (0.54-1.7 MPa). Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Destructive distillation

    Energy Technology Data Exchange (ETDEWEB)

    1938-07-05

    A process and apparatus for the destructive distillation at low temperature of mineral or organic material particularly oil shale, is given in which the process comprises distilling the material in a horizontal gaseous stream, subjecting the hot residues to the action of a gaseous stream containing a predetermined amount of oxygen so as to burn, at least partly, the carbon-containing substances, and the process uses the gases from this combustion for the indirect heating of the gases serving for the distillation.

  4. Real-time contrast ultrasound muscle perfusion imaging with intermediate-power imaging coupled with acoustically durable microbubbles.

    Science.gov (United States)

    Seol, Sang-Hoon; Davidson, Brian P; Belcik, J Todd; Mott, Brian H; Goodman, Reid M; Ammi, Azzdine; Lindner, Jonathan R

    2015-06-01

    There is growing interest in limb contrast-enhanced ultrasound (CEU) perfusion imaging for the evaluation of peripheral artery disease. Because of low resting microvascular blood flow in skeletal muscle, signal enhancement during limb CEU is prohibitively low for real-time imaging. The aim of this study was to test the hypothesis that this obstacle can be overcome by intermediate- rather than low-power CEU when performed with an acoustically resilient microbubble agent. Viscoelastic properties of Definity and Sonazoid were assessed by measuring bulk modulus during incremental increases in ambient pressure to 200 mm Hg. Comparison of in vivo microbubble destruction and signal enhancement at a mechanical index (MI) of 0.1 to 0.4 was performed by sequential reduction in pulsing interval from 10 to 0.05 sec during limb CEU at 7 MHz in mice and 1.8 MHz in dogs. Destruction was also assessed by broadband signal generation during passive cavitation detection. Real-time CEU perfusion imaging with destruction-replenishment was then performed at 1.8 MHz in dogs using an MI of 0.1, 0.2, or 0.3. Sonazoid had a higher bulk modulus than Definity (66 ± 12 vs 29 ± 2 kPa, P = .02) and exhibited less inertial cavitation (destruction) at MIs ≥ 0.2. On in vivo CEU, maximal signal intensity increased incrementally with MI for both agents and was equivalent between agents except at an MI of 0.1 (60% and 85% lower for Sonazoid at 7 and 1.8 MHz, respectively, P power imaging coupled with a durable microbubble contrast agent. Copyright © 2015 American Society of Echocardiography. All rights reserved.

  5. Minimising microbubble size through oscillation frequency control

    Czech Academy of Sciences Publication Activity Database

    Brittle, S.; Deasi, P.; Ng, W. Ch.; Dunbar, A.; Howell, R.; Tesař, Václav; Zimmerman, W. B.

    2015-01-01

    Roč. 104, December (2015), s. 357-366 ISSN 0263-8762 Institutional support: RVO:61388998 Keywords : microbubbles * process intensification * transfer phenomena Subject RIV: BK - Fluid Dynamics Impact factor: 2.525, year: 2015 http://ac.els-cdn.com/S0263876215002993/1-s2.0-S0263876215002993-main.pdf?_tid=4fca5bdc-9e5f-11e5-85c5-00000aab0f02&acdnat=1449656970_b6957d7afd64592d184a978b367e8e2a

  6. Tunable microbubble generator using electrolysis and ultrasound

    Science.gov (United States)

    Achaoui, Younes; Metwally, Khaled; Fouan, Damien; Hammadi, Zoubida; Morin, Roger; Debieu, Eric; Payan, Cédric; Mensah, Serge

    2017-01-01

    This letter reports on a method for producing on demand calibrated bubbles in a non-chemically controlled solution using localized micro-electrolysis and ultrasound. Implementing a feedback loop in the process leads to a point source of stable mono-dispersed microbubbles. This approach overcomes the inertial constraints encountered in microfluidics with the possibility to produce from a single to an array of calibrated bubbles. Moreover, this method avoids the use of additional surfactant that may modify the composition of the host fluid. It impacts across a broad range of scientific domains from bioengineering, sensing to environment.

  7. Tunable microbubble generator using electrolysis and ultrasound

    Directory of Open Access Journals (Sweden)

    Younes Achaoui

    2017-01-01

    Full Text Available This letter reports on a method for producing on demand calibrated bubbles in a non-chemically controlled solution using localized micro-electrolysis and ultrasound. Implementing a feedback loop in the process leads to a point source of stable mono-dispersed microbubbles. This approach overcomes the inertial constraints encountered in microfluidics with the possibility to produce from a single to an array of calibrated bubbles. Moreover, this method avoids the use of additional surfactant that may modify the composition of the host fluid. It impacts across a broad range of scientific domains from bioengineering, sensing to environment.

  8. [Destruction of synovial pannus of antigen-induced arthritis by ultrasonic cavitation in rabbits].

    Science.gov (United States)

    Zhang, Ling-yan; Qiu, Li; Wang, Lei; Lin, Ling; Wen, Xiao-rong

    2011-11-01

    To optimize the conditions of ultrasonic irradiation and microbubble of ultrasound cavitation on destruction of synovial pannus of antigen-induced arthritis (AIA) in rabbits. Antigen-induced arthritis was successfully induced on bilateral knee joints of 85 rabbits. Each 10 AIA rabbits were divided into two groups to compare various peak negative pressures, different ultrasonic pulse durations, various pulse repetition frequencies, different irradiance duration, different dosages of microbubble contrast agents, different ultrasonic irradiance times. With intravenous infusion of Sonovue to the rabbits, ultrasonic irradiance was performed on the right knee joint using the above condition of ultrasound cavitation. At the day 1 after ultrasonic irradiance, MRI and pathological examination were employed to evaluate the optimal conditions. The optimal parameters and conditions for ultrasonic irradiance included intermittent ultrasonic application (in 6 s intervals), 0.6 mL/kg of microbubble contrast agent, 4.6 MPa of ultrasonic peak negative pressure, 100 cycles of pulse duration, 50 Hz of pulse repetition frequency, 5 min of ultrasonic duration, 0.6 mL/kg of dosages of microbubble contrast agents and multi-sessional ultrasonic irradiance. After the ultrasonic irradiance, the thickness of right knee synovium measured by MRI was thinner than that of left knee and synovial necrosis was confirmed by the pathological finding. Under optimal ultrasonic irradiation and microbubble conditions, ultrasonic cavitation could destroy synovial pannus of AIA in rabbits.

  9. Ambient pressure sensitivity of microbubbles investigated through a parameter study

    DEFF Research Database (Denmark)

    Andersen, Klaus Scheldrup; Jensen, Jørgen Arendt

    2009-01-01

    Measurements on microbubbles clearly indicate a relation between the ambient pressure and the acoustic behavior of the bubble. The purpose of this study was to optimize the sensitivity of ambient pressure measurements, using the subharmonic component, through microbubble response simulations....... The behavior of two microbubbles corresponding to two different contrast agents was investigated as a function of driving pulse and ambient overpressure, pov. Simulations of Levovist using a rectangular driving pulse show an almost linear reduction in the subharmonic component as pov is increased. For a 20...... found, although the reduction is not completely linear as a function of the ambient pressure....

  10. Destructive, distillation

    Energy Technology Data Exchange (ETDEWEB)

    Jameson, J

    1882-10-23

    The apparatus employed resembles a reverberatory furnace, having a brickwork chamber with pipes or passages leading from the bottom, through which gases and vapors, arising from destructive distillation or heating of the materials with which the chamber is charged to a certain depth, are drawn by suction produced by a fan or blower. The materials are heated from above by firegates admitted from a separate furnace or fireplace. When shale is thus treated, to obtain burning gas, oil, and ammonia, the suction may be so regulated as to give preponderance to whichever product is desired, the depth of material treated being also concerned in the result. The process is applicable also in the treatment of coal pit refuse, sawdust, peat, and other matters, to obtain volatile products; in burning limestone to obtain carbon dioxide; and in roasting ores. Reference is made to a former Specification for coking coal, No. 1947, A. D. 1882.

  11. Distillation, destructive

    Energy Technology Data Exchange (ETDEWEB)

    Walton, G

    1865-05-16

    A retort for the destructive distillation of coal, shale, whereby hydrocarbons are produced, is described. The vertical retort is provided with a charging door, a discharging door, an outlet leading to the condensing plant, an inclined bottom, and a perforated cage to facilitate the escape of the vapor and to regulate the amount of materials operated upon in the retort. The upper part of the cage is conical to deflect the materials fed in by the door and the lower part is also slightly conical to facilitate emptying the retort. The bottom may incline from both back and front, and also from the sides to the center. The apparatus is heated from below, and the flues pass all round the lower part of the retort.

  12. Acoustically excited encapsulated microbubbles and mitigation of biofouling

    KAUST Repository

    Qamar, Adnan; Fortunato, Luca; Leiknes, TorOve

    2017-01-01

    Provided herein is a universally applicable biofouling mitigation technology using acoustically excited encapsulated microbubbles that disrupt biofilm or biofilm formation. For example, a method of reducing biofilm formation or removing biofilm in a

  13. Theragnostic ultrasound using microbubbles in the treatment of prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hak Jong; Yoon, Young Il; Bae, Yun Jung [Dept. of Radiology, Seoul National University Bundang Hospital, Seongnam (Korea, Republic of)

    2016-08-15

    The use of gas-filled microbubbles in perfusion monitoring as intravascular ultrasound contrast agents has recently become more common. Additionally, microbubbles are employed as carriers of pharmaceutical substances or genes. Microbubbles have great potential to improve the delivery of therapeutic materials into cells and to modify vascular permeability, causing increased extravasation of drugs and drug carriers. Prostate cancer is the most common neoplasm in Europe and America, with an incidence twice to three times that of lung and colorectal cancer. Its incidence is still rising in Asian countries, including Japan and Korea. In this review, we present current strategies regarding the synthesis of microbubbles with targeted ligands on their surfaces, with a focus on prostate cancer.

  14. Real-Time Two-Dimensional Imaging of Microbubble Cavitation

    NARCIS (Netherlands)

    Vignon, F.; Shi, W.T.; Powers, J.E.; Liu, J.; Drvol, L.; Lof, J.; Everbach, C.; Gao, S.; Xie, F.; Porter, T.

    2011-01-01

    Ultrasound cavitation of microbubble contrast agents has a potentialfor therapeutic applications, including sonothrombolysis in acute ischemic stroke. For safety, efficacy, and reproducibility of treatment, it is critical to evaluate the cavitation state (e.g. stable versus inertial forms of

  15. Extracellular delivery induced by ultrasound and microbubbles in cells

    Science.gov (United States)

    Hussein, Farah; Antonescu, Costin; Karshafian, Raffi

    2017-03-01

    Ultrasound and microbubble treatment (USMB) can enhance the intracellular uptake of molecules, which otherwise would be excluded from the cell, through USMB-mediated transient membrane disruption and through enhanced endocytosis. However, the effect of USMB on the outward movement of molecules from cells is not well understood. This study investigates the effects of USMB on the release of molecules from various cellular compartments including cytoplasm, lysosomes, and recycling endosomes. In vitro ARPE-19 (RPE henceforth) cells were loaded with Alexa fluor-labeled transferrin as a marker for recycling endosomes, LAMP-1 antibody was used to detect the fusion of lysosomes with the plasma membrane, GFP-transfected RPE cells were used to examine the release of GFP from the cytoplasm, and 7-AAD was used to assess cell viability. Subsequently, cells were exposed to USMB (106 cells/mL, 300 kPa peak negative pressure, 1 min treatment duration, and 20 µL/mL Definity microbubbles). Following USMB, the release of the fluorescent markers was examined at 1.5, 11.5, and 21.5 minutes from the start of USMB. The mean fluorescent intensity (MFI) of untreated and USMB treated samples were measured using flow cytometry. USMB increased the extracellular delivery of GFP molecules from the cytoplasm; the MFI in USMB treated GFP-transfected RPE cells decreased by 17% in viable cells and this MFI decreased by 70% in non-viable cells. This could be due to diffusion of GFP through the membrane disruptions induced by USMB. Additionally, the MFI of viable cells stained with LAMP-1 antibody increased by 50% and this increase was 15 folds in the non-viable cells indicating lysosome exocytosis as a mechanism for membrane repair. Furthermore, the MFI of cells loaded with fluorescent transferrin decreased by 22% after USMB treatment in viable cells, indicating a significant increase in transferrin recycling to the cell membrane. However, the increased recycling was not statistically significant

  16. Modeling photothermal and acoustical induced microbubble generation and growth.

    Science.gov (United States)

    Krasovitski, Boris; Kislev, Hanoch; Kimmel, Eitan

    2007-12-01

    Previous experimental studies showed that powerful heating of nanoparticles by a laser pulse using energy density greater than 100 mJ/cm(2), could induce vaporization and generate microbubbles. When ultrasound is introduced at the same time as the laser pulse, much less laser power is required. For therapeutic applications, generation of microbubbles on demand at target locations, e.g. cells or bacteria can be used to induce hyperthermia or to facilitate drug delivery. The objective of this work is to develop a method capable of predicting photothermal and acoustic parameters in terms of laser power and acoustic pressure amplitude that are needed to produce stable microbubbles; and investigate the influence of bubble coalescence on the thresholds when the microbubbles are generated around nanoparticles that appear in clusters. We develop and solve here a combined problem of momentum, heat and mass transfer which is associated with generation and growth of a microbubble, filled with a mixture of non-vaporized gas (air) and water vapor. The microbubble's size and gas content vary as a result of three mechanisms: gas expansion or compression, evaporation or condensation on the bubble boundary, and diffusion of dissolved air in the surrounding water. The simulations predict that when ultrasound is applied relatively low threshold values of laser and ultrasound power are required to obtain a stable microbubble from a single nanoparticle. Even lower power is required when microbubbles are formed by coalescence around a cluster of 10 nanoparticles. Laser pulse energy density of 21 mJ/cm(2) is predicted for instance together with acoustic pressure of 0.1 MPa for a cluster of 10 or 62 mJ/cm(2) for a single nanoparticle. Those values are well within the safety limits, and as such are most appealing for targeted therapeutic purposes.

  17. Destructive distillation

    Energy Technology Data Exchange (ETDEWEB)

    Young, W

    1881-04-12

    Destructive distillation of shale for the manufacture of mineral oil and ammonia is described. The retorts are arranged in benches, each retort being placed over its own combustion chamber into which the spent shale is discharged and consumed in heating the next charge as described in Specification No. 1578, A. D. 1880. Two forms of retorts are shown, each consisting of two retorts placed above and communicating with one another, the upper being employed to distill the oil at a low red heat, and the lower to eliminate the nitrogen in the form of ammonia at a much higher temperature. The retorts are divided by a sliding damper and have an outlet for the passage of the products placed at the junction. The retorts have an outlet at the top for the escape of the products. Each retort has an opening closed by a cover for charging and a door for discharging. The products of combustion from the combustion chambers pass through ports to a chamber surrounding the lower retorts and thence through ports in the division wall controlled by dampers into the chamber surrounding the upper retorts, whence they pass through flues to the chimney. Around the bottom of each retort are openings communicating with a chamber to which steam is admitted through a valve from a pipe preferably placed in a coil in the flue.

  18. Distillation, destructive

    Energy Technology Data Exchange (ETDEWEB)

    Young, W; Fyfe, J

    1897-06-03

    Improvements in retorts of the class described in Specification No. 1377, A. D. 1882, for the destructive distillation of shale are disclosed. The retorts are provided with enlarged multiple hoppers for the reception of the fresh shale, and with enlarged chambers for the reception of the exhausted shale. The hoppers are built up of steel plates, and are bolted at the bottom to flanges on the upper ends of the retorts so as to permit of differential expansion. The shale is fed continuously into the retorts by rods or chains carried by a rocking shaft, or by a slit tube attached to a rocking shaft, and in connection with the hydraulic main. The spent shale is discharged into the receiving chambers by means of a series of prongs extending through a grating and carried by a rocking shaft actuated by levers engaging with reciprocating bars. In an alternative arrangement, the pronged rocking shafts are replaced by worms or screws formed into one half with a right-hand thread and the other half with a left-hand thread.

  19. Distillation, destructive

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, J M

    1884-06-03

    The invention relates to retorts for the destructive distillation of shale, dross, and other carbonaceous or oleaginous materials, and for the distillation and carbonization of sawdust, shavings, tan bark, and the like. The material is fed from a trapped hopper on a series of trays or casings of cast iron or other material, separated by flue spaces and arranged in a tier round a vertical rotating shaft passing through tubular pieces cast on the casings. The shaft is fitted with arms which carry stirring-blades so disposed that the material is shifted from side to side and slowly fed towards the ducts through which it passes to the casing next below, and is finally withdrawn from the apparatus by a pipe, which may be trapped or otherwise. Furnace gases are admitted through openings in the enclosing brickwork having settings to support the casings, the lowermost of which may be fitted below the inlet for furnace gases and their contents cooled by the circulation of cold water round them. The gaseous or volatile products of distillation pass to a condenser by means of openings and the pipe, which may be formed in sections to obtain access to the casings, or doors may be provided for this purpose. The ducts may be arranged alternately at the edge and center of the casings, which may be jacketed, and heated air or steam may be employed instead of furnace gases. Means may also be provided for admitting superheated steam into one or more of the casings.

  20. Dynamics of microbubble oscillators with delay coupling

    Science.gov (United States)

    Heckman, C. R.; Sah, S. M.; Rand, R. H.

    2010-10-01

    We investigate the stability of the in-phase mode in a system of two delay-coupled bubble oscillators. The bubble oscillator model is based on a 1956 paper by Keller and Kolodner. Delay coupling is due to the time it takes for a signal to travel from one bubble to another through the liquid medium that surrounds them. Using techniques from the theory of differential-delay equations as well as perturbation theory, we show that the equilibrium of the in-phase mode can be made unstable if the delay is long enough and if the coupling strength is large enough, resulting in a Hopf bifurcation. We then employ Lindstedt's method to compute the amplitude of the limit cycle as a function of the time delay. This work is motivated by medical applications involving noninvasive localized drug delivery via microbubbles.

  1. Distillation, destructive

    Energy Technology Data Exchange (ETDEWEB)

    Young, W; Neilson, A; Young, A

    1876-10-09

    The invention relates to modifications of the retort apparatus, described in Specification No. 2487, A.D. 1872, for the destructive distillation of shale and other bituminous substances. The retorts instead of being worked continuously are completely filled and completely discharged in turn. They are made oblong in cross-section in order to present the material in thin layers and cause it to be acted upon more rapidly and economically. The retorts can thus be heated solely by the combustion of the carbonaceus matter contained in the discharged residues or with a small amount of coal in addition. Each retort is contracted at the bottom and is fitted with a box or chest having a hole in it corresponding to the opening in the retort and a sliding plate of iron, firebrick, or other suitable material, which can be operated by a rod passing through the front of the box, for opening or closing the retort. Underneath the box and over the combustion chamber are placed fireclay blocks leaving an opening, which can be closed by another plate of firebrick or the like. When distillation commences, the gases and vapors in the retort are drawn off through a pipe and a main by an exhauster. In order to prevent air from entering the retort or hydrocarbon vapor from being puffed back by the action of the wind, the gas which remains after the condensation of the oils is forced back into the box between the plates and part of it enters the retort and part the combustion chamber. In order to avoid the liability of the oil being carried past the condensers by the action of the gas, steam may be used as a substitute for the gas or mixed with it in large proportions, a steam jet being used to force the gas into the main supplying the boxes.

  2. Non-linear Response and Viscoelastic Properties of Lipid-Coated Microbubbles: DSPC versus DPPC

    NARCIS (Netherlands)

    van Rooij, T.; Luan, Y.; Renaud, G.; van der Steen, A.F.W.; Versluis, Michel; de Jong, N.; Kooiman, K.

    2015-01-01

    For successful in vivo contrast-enhanced ultrasound imaging (CEUS) and ultrasound molecular imaging, detailed knowledge of stability and acoustical properties of the microbubbles is essential. Here, we compare these aspects of lipid-coated microbubbles that have either

  3. Microbubble enhanced ozonation process for advanced treatment of wastewater produced in acrylic fiber manufacturing industry

    KAUST Repository

    Zheng, Tianlong; Wang, Qunhui; Zhang, Tao; Shi, Zhining; Tian, Yanli; Shi, Shanshan; Smale, Nicholas; Wang, Juan

    2015-01-01

    zeta potential of the bubbles were also observed in the microbubble ozonation process. The biodegradability of the wastewater was also significantly improved by microbubble-ozonation, which was ascribed to the enhanced degradation of alkanes, aromatic

  4. Design and Control of Functional Microbubbles for Medical Applications of Ultrasound

    Science.gov (United States)

    Takagi, Shu; Osaki, Taichi; Ariyoshi, Takuya; Azuma, Takashi; Ichiyanagi, Mitsuhisa; Kinefuchi, Ikuya

    2015-11-01

    Microbubbles are used as a contrast agent for ultrasound diagnosis. It is also expected to be use for the treatment. One of the possible applications is microbubble DDS. For that purpose, microbubbles need to be well-controlled for the generating process and manipulation. In this talk, for the design and control of the functional microbubbles, an experimental study on generation and surface modification of microbubbles are explained. Using a T-junction type microchannel, small bubbles about 5 μm size are successfully generated. For the surface modification, Biotin-coated microbubbles are tried to adhere the Avidin-coated wall. Furthermore, the manipulation of the microbubbles using ultrasound is also discussed. Plane-wave and focused ultrasound is used to manipulate a microbubble and bubble clusters. The experimental results are shown in the presentation. Supported by JSPS KAKENHI Grant Number 15K13865.

  5. Quantitative ultrasound characterization of tumor cell death: ultrasound-stimulated microbubbles for radiation enhancement.

    Directory of Open Access Journals (Sweden)

    Hyunjung Christina Kim

    Full Text Available The aim of this study was to assess the efficacy of quantitative ultrasound imaging in characterizing cancer cell death caused by enhanced radiation treatments. This investigation focused on developing this ultrasound modality as an imaging-based non-invasive method that can be used to monitor therapeutic ultrasound and radiation effects. High-frequency (25 MHz ultrasound was used to image tumor responses caused by ultrasound-stimulated microbubbles in combination with radiation. Human prostate xenografts grown in severe combined immunodeficiency (SCID mice were treated using 8, 80, or 1000 µL/kg of microbubbles stimulated with ultrasound at 250, 570, or 750 kPa, and exposed to 0, 2, or 8 Gy of radiation. Tumors were imaged prior to treatment and 24 hours after treatment. Spectral analysis of images acquired from treated tumors revealed overall increases in ultrasound backscatter intensity and the spectral intercept parameter. The increase in backscatter intensity compared to the control ranged from 1.9±1.6 dB for the clinical imaging dose of microbubbles (8 µL/kg, 250 kPa, 2 Gy to 7.0±4.1 dB for the most extreme treatment condition (1000 µL/kg, 750 kPa, 8 Gy. In parallel, in situ end-labelling (ISEL staining, ceramide, and cyclophilin A staining demonstrated increases in cell death due to DNA fragmentation, ceramide-mediated apoptosis, and release of cyclophilin A as a result of cell membrane permeabilization, respectively. Quantitative ultrasound results indicated changes that paralleled increases in cell death observed from histology analyses supporting its use for non-invasive monitoring of cancer treatment outcomes.

  6. A novel technology: microfluidic devices for microbubble ultrasound contrast agent generation.

    Science.gov (United States)

    Lin, Hangyu; Chen, Junfang; Chen, Chuanpin

    2016-09-01

    Microbubbles are used as ultrasound contrast agents, which enhance ultrasound imaging techniques. In addition, microbubbles currently show promise in disease therapeutics. Microfluidic devices have increased the ability to produce microbubbles with precise size, and high monodispersity compared to microbubbles created using traditional methods. This paper will review several variations in microfluidic device structures used to produce microbubbles as ultrasound contrast agents. Microfluidic device structures include T-junction, and axisymmetric and asymmetric flow-focusing. These devices have made it possible to produce microbubbles that can enter the vascular space; these microbubbles must be less than 10 μm in diameter and have high monodispersity. For different demands of microbubbles production rate, asymmetric flow-focusing devices were divided into individual and integrated devices. In addition, asymmetric flow-focusing devices can produce double layer and multilayer microbubbles loaded with drug or biological components. Details on the mechanisms of both bubble formation and device structures are provided. Finally, microfluidically produced microbubble acoustic responses, microbubble stability, and microbubble use in ultrasound imaging are discussed.

  7. Ultrasound mediated nanoparticle drug delivery

    Science.gov (United States)

    Mullin, Lee B.

    Ultrasound is not only a powerful diagnostic tool, but also a promising therapeutic technology that can be used to improve localized drug delivery. Microbubble contrast agents are micron sized encapsulated gas filled bubbles that are administered intravenously. Originally developed to enhance ultrasound images, microbubbles are highly echogenic due to the gas core that provides a detectable impedance difference from the surrounding medium. The core also allows for controlled response of the microbubbles to ultrasound pulses. Microbubbles can be pushed using acoustic radiation force and ruptured using high pressures. Destruction of microbubbles can increase permeability at the cellular and vascular level, which can be advantageous for drug delivery. Advances in drug delivery methods have been seen with the introduction of nanoparticles, nanometer sized objects often carrying a drug payload. In chemotherapy, nanoparticles can deliver drugs to tumors while limiting systemic exposure due to abnormalities in tumor vasculature such large gaps between endothelial cells that allow nanoparticles to enter into the interstitial space; this is referred to as the enhanced permeability and retention (EPR) effect. However, this effect may be overestimated in many tumors. Additionally, only a small percentage of the injected dose accumulates in the tumor, which most the nanoparticles accumulating in the liver and spleen. It is hypothesized that combining the acoustic activity of an ultrasound contrast agent with the high payload and extravasation ability of a nanoparticle, localized delivery to the tumor with reduced systemic toxicity can be achieved. This method can be accomplished by either loading nanoparticles onto the shell of the microbubble or through a coadministration method of both nanoparticles and microbubbles. The work presented in this dissertation utilizes novel and commercial nanoparticle formulations, combined with microbubbles and a variety of ultrasound systems

  8. Therapeutic effects of microbubble added to combined high-intensity focused ultrasound and chemotherapy in a pancreatic cancer xenograft model

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Mi Hye [Dept. of Radiology, Konkuk University Medical Center, Seoul (Korea, Republic of); Lee, Jae Young; Kim, Bo Ram; Park, Eun Joo; Kim, Hoe Suk; Han, Joon Koo [Dept. of Radiology, Seoul National University Hospital, Seoul (Korea, Republic of); Kim, Hae Ri [Dept. of Pre-Dentistry, Gangneung-Wonju National University College of Dentistry, Gangneung (Korea, Republic of); Choi, Byung Ihn [Dept. of Radiology, Chung-Ang University Hospital, Seoul (Korea, Republic of)

    2016-09-15

    To investigate whether high-intensity focused ultrasound (HIFU) combined with microbubbles enhances the therapeutic effects of chemotherapy. A pancreatic cancer xenograft model was established using BALB/c nude mice and luciferase-expressing human pancreatic cancer cells. Mice were randomly assigned to five groups according to treatment: control (n = 10), gemcitabine alone (GEM; n = 12), HIFU with microbubbles (HIFU + MB, n = 11), combined HIFU and gemcitabine (HIGEM; n = 12), and HIGEM + MB (n = 13). After three weekly treatments, apoptosis rates were evaluated using the terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling assay in two mice per group. Tumor volume and bioluminescence were monitored using high-resolution 3D ultrasound imaging and in vivo bioluminescence imaging for eight weeks in the remaining mice. The HIGEM + MB group showed significantly higher apoptosis rates than the other groups (p < 0.05) and exhibited the slowest tumor growth. From week 5, the tumor-volume-ratio relative to the baseline tumor volume was significantly lower in the HIGEM + MB group than in the control, GEM, and HIFU + MB groups (p < 0.05). Despite visible distinction, the HIGEM and HIGEM + MB groups showed no significant differences. High-intensity focused ultrasound combined with microbubbles enhances the therapeutic effects of gemcitabine chemotherapy in a pancreatic cancer xenograft model.

  9. Therapeutic Effects of Microbubbles Added to Combined High-Intensity Focused Ultrasound and Chemotherapy in a Pancreatic Cancer Xenograft Model

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Mi Hye [Department of Radiology, Konkuk University Medical Center, Seoul 05030 (Korea, Republic of); Lee, Jae Young [Department of Radiology, Seoul National University Hospital, Seoul 03080 (Korea, Republic of); Kim, Hae Ri [Department of Pre-Dentistry, Gangneung-Wonju National University College of Dentistry, Gangneung 25457 (Korea, Republic of); Kim, Bo Ram; Park, Eun-Joo; Kim, Hoe Suk; Han, Joon Koo [Department of Radiology, Seoul National University Hospital, Seoul 03080 (Korea, Republic of); Choi, Byung Ihn [Department of Radiology, Chung-Ang University Hospital, Seoul 06973 (Korea, Republic of)

    2016-11-01

    To investigate whether high-intensity focused ultrasound (HIFU) combined with microbubbles enhances the therapeutic effects of chemotherapy. A pancreatic cancer xenograft model was established using BALB/c nude mice and luciferase-expressing human pancreatic cancer cells. Mice were randomly assigned to five groups according to treatment: control (n = 10), gemcitabine alone (GEM; n = 12), HIFU with microbubbles (HIFU + MB, n = 11), combined HIFU and gemcitabine (HIGEM; n = 12), and HIGEM + MB (n = 13). After three weekly treatments, apoptosis rates were evaluated using the terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling assay in two mice per group. Tumor volume and bioluminescence were monitored using high-resolution 3D ultrasound imaging and in vivo bioluminescence imaging for eight weeks in the remaining mice. The HIGEM + MB group showed significantly higher apoptosis rates than the other groups (p < 0.05) and exhibited the slowest tumor growth. From week 5, the tumor-volume-ratio relative to the baseline tumor volume was significantly lower in the HIGEM + MB group than in the control, GEM, and HIFU + MB groups (p < 0.05). Despite visible distinction, the HIGEM and HIGEM + MB groups showed no significant differences. High-intensity focused ultrasound combined with microbubbles enhances the therapeutic effects of gemcitabine chemotherapy in a pancreatic cancer xenograft model.

  10. Controlling particle trajectories using oscillating microbubbles

    Science.gov (United States)

    Jalikop, Shreyas; Wang, Cheng; Hilgenfeldt, Sascha

    2010-11-01

    In many applications of microfluidics and biotechnology, such as cytometry and drug delivery, it is vital to manipulate the trajectories of microparticles such as vesicles or cells. On this small scale, inertial or gravitational effects are often too weak to exploit. We propose a mechanism to selectively trap and direct particles based on their size in creeping transport flows (Re1). We employ Rayleigh-Nyborg-Westervelt (RNW) streaming generated by an oscillating microbubble, which in turn generates a streaming flow component around the mobile particles. The result is an attractive interaction that draws the particle closer to the bubble. The impenetrability of the bubble interface destroys time-reversal symmetry and forces the particles onto either narrow trajectory bundles or well-defined closed trajectories, where they are trapped. The effect is dependent on particle size and thus allows for the passive focusing and sorting of selected sizes, on scales much smaller than the geometry of the microfluidic device. The device could eliminate the need for complicated microchannel designs with external magnetic or electric fields in applications such as particle focusing and size-based sorting.

  11. Manipulation of Microbubble Clusters Using Focused Ultrasound

    Science.gov (United States)

    Matsuzaki, Hironobu; Osaki, Taichi; Kawaguchi, Kei; Unga, Johan; Ichiyanagi, Mitsuhisa; Azuma, Takashi; Suzuki, Ryo; Maruyama, Kazuo; Takagi, Shu

    2017-11-01

    In recent years, microbubbles (MBs) are expected to be utilized for the ultrasound drug delivery system (DDS). For the MB-DDS, it is important to establish a method of controlling bubbles and bubble clusters using ultrasound field. The objective of this study is to clarify behaviors of bubble clusters with various physical conditions. MBs in the ultrasound field are subjected to the primary Bjerknes force. The force traps MBs at the focal region of the focused ultrasound field. The trapped MBs form a bubble cluster at the region. A bubble cluster continues growing with absorbing surrounding bubbles until it reaches a maximum size beyond which it disappears from the focal region. In the present study, two kinds of MBs are used for the experiment. One is Sonazoid with average diameter of 2.6 um and resonant frequency of 5 MHz. The other is developed by Teikyo Univ., with average diameter of 1.5 um and presumed resonant frequency of 4 MHz. The bubble cluster's behaviors are analyzed using the high-speed camera. Sonazoid clusters have larger critical size than the other in every frequency, and its cluster size is inversely proportional to the ultrasound frequency, while Teikyo-bubble clusters have different tendency. These results are discussed in the presentation.

  12. Robust microbubble tracking for super resolution imaging in ultrasound

    DEFF Research Database (Denmark)

    Hansen, Kristoffer B.; Villagómez Hoyos, Carlos Armando; Brasen, Jens Christian

    2016-01-01

    Currently ultrasound resolution is limited by diffraction to approximately half the wavelength of the sound wave employed. In recent years, super resolution imaging techniques have overcome the diffraction limit through the localization and tracking of a sparse set of microbubbles through...... the vasculature. However, this has only been performed on fixated tissue, limiting its clinical application. This paper proposes a technique for making super resolution images on non-fixated tissue by first compensating for tissue movement and then tracking the individual microbubbles. The experiment is performed...... on the kidney of a anesthetized Sprage-Dawley rat by infusing SonoVue at 0.1× original concentration. The algorithm demonstrated in vivo that the motion compensation was capable of removing the movement caused by the mechanical ventilator. The results shows that microbubbles were localized with a higher...

  13. Superparamagnetic nanoparticle-inclusion microbubbles for ultrasound contrast agents

    International Nuclear Information System (INIS)

    Yang Fang; Li Yixin; Chen Zhongping; Gu Ning; Li Ling; Wu Junru

    2008-01-01

    We have developed a new type of ultrasound (US) contrast agent, consisting of a gas core, a layer of superparamagnetic iron oxide Fe 3 O 4 nanoparticles (SPIO) and an oil in water outermost layer. The newly developed US contrast agent microbubbles have a mean diameter of 760 nm with a polydisperity index (PI) of 0.699. Our in vitro and in vivo experiments have shown that they have the following advantages compared to gas-encapsulated microbbubbles without SPIO inclusion: (1) they provide better contrast for US images; (2) the SPIO-inclusion microbubbles generate a higher backscattering signal; the mean grey scale is 97.9, which is 38.6 higher than that of microbubbles without SPIO; and (3) since SPIO can also serve as a contrast agent of magnetic resonance images (MRI) in vitro, they can be potentially used as contrast agents for double-modality (MRI and US) clinical studies.

  14. Modeling Encapsulated Microbubble Dynamics at High Pressure Amplitudes

    Science.gov (United States)

    Heyse, Jan F.; Bose, Sanjeeb; Iaccarino, Gianluca

    2017-11-01

    Encapsulated microbubbles are commonly used in ultrasound contrast imaging and are of growing interest in therapeutic applications where local cavitation creates temporary perforations in cell membranes allowing for enhanced drug delivery. Clinically used microbubbles are encapsulated by a shell commonly consisting of protein, polymer, or phospholipid; the response of these bubbles to externally imposed ultrasound waves is sensitive to the compressibility of the encapsulating shell. Existing models approximate the shell compressibility via an effective surface tension (Marmottant et al. 2005). We present simulations of microbubbles subjected to high amplitude ultrasound waves (on the order of 106 Pa) and compare the results with the experimental measurements of Helfield et al. (2016). Analysis of critical points (corresponding to maximum and minimum expansion) in the governing Rayleigh-Plesset equation is used to make estimates of the parameters used to characterize the effective surface tension of the encapsulating shell. Stanford Graduate Fellowship.

  15. Power cavitation-guided blood-brain barrier opening with focused ultrasound and microbubbles

    Science.gov (United States)

    Burgess, M. T.; Apostolakis, I.; Konofagou, E. E.

    2018-03-01

    Image-guided monitoring of microbubble-based focused ultrasound (FUS) therapies relies on the accurate localization of FUS-stimulated microbubble activity (i.e. acoustic cavitation). Passive cavitation imaging with ultrasound arrays can achieve this, but with insufficient spatial resolution. In this study, we address this limitation and perform high-resolution monitoring of acoustic cavitation-mediated blood-brain barrier (BBB) opening with a new technique called power cavitation imaging. By synchronizing the FUS transmit and passive receive acquisition, high-resolution passive cavitation imaging was achieved by using delay and sum beamforming with absolute time delays. Since the axial image resolution is now dependent on the duration of the received acoustic cavitation emission, short pulses of FUS were used to limit its duration. Image sets were acquired at high-frame rates for calculation of power cavitation images analogous to power Doppler imaging. Power cavitation imaging displays the mean intensity of acoustic cavitation over time and was correlated with areas of acoustic cavitation-induced BBB opening. Power cavitation-guided BBB opening with FUS could constitute a standalone system that may not require MRI guidance during the procedure. The same technique can be used for other acoustic cavitation-based FUS therapies, for both safety and guidance.

  16. Ultrasound imaging of the mouse pancreatic duct using lipid microbubbles

    Science.gov (United States)

    Banerjee, B.; McKeown, K. R.; Skovan, B.; Ogram, E.; Ingram, P.; Ignatenko, N.; Paine-Murrieta, G.; Witte, R.; Matsunaga, T. O.

    2012-03-01

    Research requiring the murine pancreatic duct to be imaged is often challenging due to the difficulty in selectively cannulating the pancreatic duct. We have successfully catheterized the pancreatic duct through the common bile duct in severe combined immune deficient (SCID) mice and imaged the pancreatic duct with gas filled lipid microbubbles that increase ultrasound imaging sensitivity due to exquisite scattering at the gas/liquid interface. A SCID mouse was euthanized by CO2, a midline abdominal incision made, the common bile duct cut at its midpoint, a 2 cm, 32 gauge tip catheter was inserted about 1 mm into the duct and tied with suture. The duodenum and pancreas were excised, removed in toto, embedded in agar and an infusion pump was used to instill normal saline or lipid-coated microbubbles (10 million / ml) into the duct. B-mode images before and after infusion of the duct with microbubbles imaged the entire pancreatic duct (~ 1 cm) with high contrast. The microbubbles were cavitated by high mechanical index (HMI) ultrasound for imaging to be repeated. Our technique of catheterization and using lipid microbubbles as a contrast agent may provide an effective, affordable technique of imaging the murine pancreatic duct; cavitation with HMI ultrasound would enable repeated imaging to be performed and clustering of targeted microbubbles to receptors on ductal cells would allow pathology to be localized accurately. This research was supported by the Experimental Mouse Shared Service of the AZ Cancer Center (Grant Number P30CA023074, NIH/NCI and the GI SPORE (NIH/NCI P50 CA95060).

  17. Effect of microbubble ligation to cells on ultrasound signal enhancement: implications for targeted imaging.

    Science.gov (United States)

    Lankford, Miles; Behm, Carolyn Z; Yeh, James; Klibanov, Alexander L; Robinson, Peter; Lindner, Jonathan R

    2006-10-01

    Molecular imaging with contrast-enhanced ultrasound (CEU) relies on the detection of microbubbles retained in regions of disease. The aim of this study was to determine whether microbubble attachment to cells influences their acoustic signal generation and stability. Biotinylated microbubbles were attached to streptavidin-coated plates to derive density versus intensity relations during low- and high-power imaging. To assess damping from microbubble attachment to solid or cell surfaces, in vitro imaging was performed for microbubbles charge-coupled to methacrylate spheres and for vascular cell adhesion molecule-1-targeted microbubbles attached to endothelial cells. Signal enhancement on plates increased according to acoustic power and microbubble site density up to 300 mm. Microbubble signal was reduced by attachment to solid spheres during high- and low-power imaging but was minimally reduced by attachment to endothelial cells and only at low power. Attachment of targeted microbubbles to rigid surfaces results in damping and a reduction of their acoustic signal, which is not seen when microbubbles are attached to cells. A reliable concentration versus intensity relationship can be expected from microbubble attachment to 2-dimensional surfaces until a very high site density is reached.

  18. Simulation of microbubble response to ambient pressure changes

    DEFF Research Database (Denmark)

    Andersen, Klaus Scheldrup; Jensen, Jørgen Arendt

    2008-01-01

    The theory on microbubbles clearly indicates a relation between the ambient pressure and the acoustic behavior of the bubble. The purpose of this study was to optimize the sensitivity of ambient pressure measurements, using the subharmonic component, through microbubble response simulations....... The behaviour of two different contrast agents was investigated as a function of driving pulse and ambient overpressure, pov. Simulations of Levovist using a rectangular driving pulse show an almost linear reduction in the subharmonic component as pov is increased. For a 20 cycles driving pulse, a reduction...... is not completely linear as a function of the ambient pressure....

  19. DNA fragmentation: manifestation of target cell destruction mediated by cytotoxic T-cell lines, lymphotoxin-secreting helper T-cell clones, and cell-free lymphotoxin-containing supernatant

    International Nuclear Information System (INIS)

    Schmid, D.S.; Tite, J.P.; Ruddle, N.H.

    1986-01-01

    A Lyt-2 + , trinitrophenyl-specific, lymphotoxin-secreting, cytotoxic T-cell line, PCl 55, mediates the digestion of target cell DNA into discretely sized fragments. This phenomenon manifests itself within 30 min after effector cell encounter as measured by the release of 3 H counts from target cells prelabeled with [ 3 H]deoxythymidine and occurs even at very low effector to target cell ratios (0.25:1). A Lyt-1 + , ovalbumin-specific, lymphotoxin-secreting T-helper cell clone, 5.9.24, is also able to mediate fragmentation of target cell DNA over a time course essentially indistinguishable from the cytotoxic T lymphocyte-mediated hit. Cell-free lymphotoxin-containing supernatants also cause release of DNA from targets, although they require a longer time course, on the order of 24 hr. In contrast, lysis of cells by antibody plus complement or Triton X-100 does not result in DNA release even after extended periods of incubation (24 hr). All three treatments that result in the release of DNA from cells cause fragmentation of that DNA into discretely sized pieces that are multiples of 200 base pairs. The results thus suggest that cytotoxic T cells, lymphotoxin-secreting helper clones with cytolytic activity, and lymphotoxin all effect target cell destruction by means of a similar mechanism and that observed differences in time course and the absence of target cell specificity in killing mediated by lymphotoxin may simply reflect differences in the mode of toxin delivery

  20. Biological in situ characterization of polymeric microbubble contrast agents

    NARCIS (Netherlands)

    Wan, Sha; Egri, Gabriella; Oddo, Letizia; Cerroni, Barbara; Dähne, Lars; Paradossi, Gaio; Salvati, Anna; Lynch, Iseult; Dawson, Kenneth A; Monopoli, Marco P

    Polymeric microbubbles (MBs) are gas filled particles composed of a thin stabilized polymer shell that have been recently developed as valid contrast agents for the combined use of ultrasonography (US), magnetic resonance imaging (MRI) and single photon emission computer tomography (SPECT) imaging.

  1. Mechanisms of pancreatic islet cell destruction. Dose-dependent cytotoxic effect of soluble blood mononuclear cell mediators on isolated islets of Langerhans

    DEFF Research Database (Denmark)

    Mandrup-Poulsen, T; Bendtzen, K; Nerup, J

    1986-01-01

    Supernatants of peripheral blood mononuclear cells from healthy human donors stimulated with recall antigen (purified protein derivative of tuberculin) or lectin (phytohaemagglutinin) markedly inhibited the insulin release from isolated human and rat islets of Langerhans, and decreased rat islet...... reconstituted with tuberculin or phytohaemagglutinin did not impair islet function. Electron microscopy demonstrated that supernatants were cytotoxic to islet cells. The cytotoxic mononuclear cell mediator(s) was non-dialysable, sensitive to heating to 56 degrees C, labile even when stored at -70 degrees C...

  2. Non-destructive Engineering

    International Nuclear Information System (INIS)

    Ko, Jin Hyeon; Ryu, Taek In; Ko, Jun Bin; Hwang, Yong Hwa

    2006-08-01

    This book gives descriptions of non-destructive engineering on outline of non-destructive test, weld defects, radiographic inspection radiography, ultrasonic inspection, magnetic particle testing, liquid penetrant testing, eddy current inspection method, strain measurement, acoustic emission inspection method, other non-destructive testing like leakage inspection method, and non-destructive mechanics for fault analysis such as Griffiths creaking theory, and stress analysis of creaking.

  3. Development of microbubble contrast agents for high frequency ultrasound microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Jun, Se Jung; Kim, Eun A; Park, Sung Hoon; Lee, Hye Jin; Jun, Hong Young; Byun, Seung Jae; Yoon, Kwon Ha [Wonkwang University School of Medicine, Iksan (Korea, Republic of)

    2007-05-15

    To develop optimal microbubble contrast agents (MBCAs) for performing ultrasound microscopy when examining small animals. We prepared three types of MBCAs. First, a mixture of three parts of 40% dextran and one part of 5% human serum albumin were sonicated with perfluorocarbon (PFC) (MB{sub 1}-D40A5P). Second, three parts of 40% dextran and one part of 1% human serum albumin were sonicated with PFC (MB{sub 2}-D40A1P). Third, all parts of 1% bovine serum albumin were sonicated with PFC (MB{sub 3}-A1P). We measured the microbubbles' sizes and concentrations with using image analysis software. The acoustic properties of the microbubbles were assessed both in vitro and in vivo. The majority of the MB{sub 1}-D40A5Ps had a diameter of 2-5 {mu} m, the mean diameter of the MB{sub 2}-D40A1Ps was 2.5 {mu} m, and the mean diameter of the MB{sub 3}-A1Ps was less than 2.0 {mu} m. Among the microbubbles, the MB{sub 1}-D40A5Ps and MB{sub 2}-D40A1Ps showed increased echogenicity in the abdominal vessels, but the duration of their contrast effect was less than 30 sec. On the contrary, the MB3-A1Ps exhibited strong enhancement in the vessels and their duration was greater than 120 sec. A microbubble contrast agent consisting of all parts of 1% serum albumin sonicated with PFC is an effective contrast agent for ultrasound microscopy.

  4. PIV measurement of a contraction flow using micro-bubble tracer

    International Nuclear Information System (INIS)

    Ishikawa, Masaaki; Irabu, Kunio; Teruya, Isao; Nitta, Munehiro

    2009-01-01

    Recently, a technique using the micro-bubbles is focused. It was applied to many fields such as purification of rivers and lakes, washing the industrial parts, growth of plants and marine products. The characteristics of micro-bubbles are small size, wide surface area, low terminal velocity, and so on. If this micro-bubble is available as tracer of PIV (Particle Image Velocimetry), environment load would become lower because it doesn't need to discard particle. In this paper, we make a micro-bubble generator with Venturi type mechanism. The generated micro-bubbles are applied to a vertical channel flow with contraction. We validate about traceability of the micro-bubble tracer in comparison with the particle tracer.

  5. Aptamer-crosslinked microbubbles: smart contrast agents for thrombin-activated ultrasound imaging.

    Science.gov (United States)

    Nakatsuka, Matthew A; Mattrey, Robert F; Esener, Sadik C; Cha, Jennifer N; Goodwin, Andrew P

    2012-11-27

    Thrombosis, or malignant blood clotting, is associated with numerous cardiovascular diseases and cancers. A microbubble contrast agent is presented that produces ultrasound harmonic signal only when exposed to elevated thrombin levels. Initially silent microbubbles are activated in the presence of both thrombin-spiked and freshly clotting blood in three minutes with detection limits of 20 nM thrombin and 2 aM microbubbles. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Ultrasound in Biomedical Engineering: Ultrasound Microbubble Contrast Agents Promote Transdermal Permeation of Drugs

    OpenAIRE

    Ai-Ho Liao

    2016-01-01

    This report discusses a new development in the use of ultrasound microbubble contrast agents on transdermal drug delivery. The medium surrounding the microbubbles at the optimum concentration from liquid to gel can be modified and it can still achieve the same enhancement for transdermal drug permeation as liquid medium. It was also found that under the same ultrasound power density, microbubbles of larger particle sizes can extend the penetration depths of dye at the phantom surface.

  7. Phase contrast imaging of preclinical portal vein embolization with CO2 microbubbles.

    Science.gov (United States)

    Tang, Rongbiao; Yan, Fuhua; Yang, Guo Yuan; Chen, Ke Min

    2017-11-01

    Preoperative portal vein embolization (PVE) is employed clinically to avoid postoperative liver insufficiency. Animal models are usually used to study PVE in terms of mechanisms and pathophysiological changes. PVE is formerly monitored by conventional absorption contrast imaging (ACI) with iodine contrast agent. However, the side effects induced by iodine can give rise to animal damage and death. In this study, the feasibility of using phase contrast imaging (PCI) to show PVE using homemade CO 2 microbubbles in living rats has been investigated. CO 2 gas was first formed from the reaction between citric acid and sodium bicarbonate. The CO 2 gas was then encapsulated by egg white to fabricate CO 2 microbubbles. ACI and PCI of CO 2 microbubbles were performed and compared in vitro. An additional increase in contrast was detected in PCI. PCI showed that CO 2 microbubbles gradually dissolved over time, and the remaining CO 2 microbubbles became larger. By PCI, the CO 2 microbubbles were found to have certain stability, suggesting their potential use as embolic agents. CO 2 microbubbles were injected into the main portal trunk to perform PVE in living rats. PCI exploited the differences in the refractive index and facilitated clear visualization of the PVE after the injection of CO 2 microbubbles. Findings from this study suggest that homemade CO 2 microbubbles-based PCI is a novel modality for preclinical PVE research.

  8. Rest-Stress Limb Perfusion Imaging in Humans with Contrast Ultrasound Using Intermediate-Power Imaging and Microbubbles Resistant to Inertial Cavitation.

    Science.gov (United States)

    Davidson, Brian P; Hodovan, James; Belcik, J Todd; Moccetti, Federico; Xie, Aris; Ammi, Azzdine Y; Lindner, Jonathan R

    2017-05-01

    Contrast-enhanced ultrasound (CEU) limb perfusion imaging is a promising approach for evaluating peripheral artery disease (PAD). However, low signal enhancement in skeletal muscle has necessitated high-power intermittent imaging algorithms, which are not clinically feasible. We hypothesized that CEU using a combination of intermediate power and a contrast agent resistant to inertial cavitation would allow real-time limb stress perfusion imaging. In normal volunteers, CEU of the calf skeletal muscle was performed on separate days with Sonazoid, Optison, or Definity. Progressive reduction in the ultrasound pulsing interval was used to assess the balance between signal enhancement and agent destruction at escalating mechanical indices (MI, 0.1-0.4). Real-time perfusion imaging at MI 0.1-0.4 using postdestructive replenishment kinetics was performed at rest and during 25 W plantar flexion contractile exercise. For Optison, limb perfusion imaging was unreliable at rest due to very low signal enhancement generated at all MIs and was possible during exercise-induced hyperemia only at MI 0.1 due to agent destruction at higher MIs. For Definity, signal intensity progressively increased with MI but was offset by microbubble destruction, which resulted in modest signal enhancement during CEU perfusion imaging and distortion of replenishment curves at MI ≥ 0.2. For Sonazoid, there strong signal enhancement at MI ≥ 0.2, with little destruction detected only at MI 0.4. Accordingly, high signal intensity and nondistorted perfusion imaging was possible at MI 0.2-0.3 and detected an 8.0- ± 5.7-fold flow reserve. Rest-stress limb perfusion imaging in humans with real-time CEU, which requires only seconds to perform, is possible using microbubbles with viscoelastic properties that produce strong nonlinear signal generation without destruction at intermediate acoustic pressures. Copyright © 2016 American Society of Echocardiography. All rights reserved.

  9. Coupled dynamics of translation and collapse of acoustically driven microbubbles.

    Science.gov (United States)

    Reddy, Anil J; Szeri, Andrew J

    2002-10-01

    Pressure gradients drive the motion of microbubbles relative to liquids in which they are suspended. Examples include the hydrostatic pressure due to a gravitational field, and the pressure gradients in a sound field, useful for acoustic levitation. In this paper, the equations describing the coupled dynamics of radial oscillation and translation of a microbubble are given. The formulation is based on a recently derived expression for the hydrodynamic force on a bubble of changing size in an incompressible liquid [J. Magnaudet and D. Legendre, Phys. Fluids 10, 550-556 (1998)]. The complex interaction between radial and translation dynamics is best understood by examination of the added momentum associated with the liquid motion caused by the moving bubble. Translation is maximized when the bubble collapses violently. The new theory for coupled collapse and translation dynamics is compared to past experiments and to previous theories for decoupled translation dynamics. Special attention is paid to bubbles of relevance in biomedical applications.

  10. A co-flow-focusing monodisperse microbubble generator

    KAUST Repository

    Zhang, Jiaming; Li, Erqiang; Thoroddsen, Sigurdur T

    2014-01-01

    We use a simple and inexpensive microfluidic device, which is based on microscope glass slides and two tapered glass capillaries, to produce monodisperse microbubbles. The innermost capillary used for transporting the gas is inserted into the second capillary, with its 2 μm sharp tip aligned with the center of the converging-diverging throat of the second capillary. This configuration provides a small and smooth gas flow rate, and a high velocity gradient at the tube outlet. Highly monodisperse microbubbles with diameters ranging from 3.5 to 60 microns have been successfully produced at a rate of up to 40 kHz. A simple scaling law, which is based on the capillary number and liquid-to-gas flow rate ratio, successfully predicts the bubble size. © 2014 IOP Publishing Ltd.

  11. A co-flow-focusing monodisperse microbubble generator

    KAUST Repository

    Zhang, Jiaming

    2014-02-14

    We use a simple and inexpensive microfluidic device, which is based on microscope glass slides and two tapered glass capillaries, to produce monodisperse microbubbles. The innermost capillary used for transporting the gas is inserted into the second capillary, with its 2 μm sharp tip aligned with the center of the converging-diverging throat of the second capillary. This configuration provides a small and smooth gas flow rate, and a high velocity gradient at the tube outlet. Highly monodisperse microbubbles with diameters ranging from 3.5 to 60 microns have been successfully produced at a rate of up to 40 kHz. A simple scaling law, which is based on the capillary number and liquid-to-gas flow rate ratio, successfully predicts the bubble size. © 2014 IOP Publishing Ltd.

  12. Microbubbles as drug delivery systems in cerebrovascular diseases.

    Science.gov (United States)

    Spinelli, Mariacarmela; Demitri, Christian; Sannino, Alessandro; Peruzzotti-Jametti, Luca; Bacigaluppi, Marco; Comi, Giancarlo; Corea, Francesco

    2009-11-01

    The field of neurovascular ultrasound is growing rapidly with new applications. While ultrasound contrast agents were initially used to overcome poor transcranial bone windows for identification of cerebral arteries, newgeneration microbubbles in combination with innovative contrast-specific ultrasound techniques now enable potential therapeutic procedures. This article will provide a review of recent and emerging developments along with patents in ultrasound technology and contrast-specific therapeutic techniques for cerebrovascular patients.

  13. Microbubble generator excited by fluidic oscillator's third harmonic frequency

    Czech Academy of Sciences Publication Activity Database

    Tesař, Václav

    2014-01-01

    Roč. 92, č. 9 (2014), s. 1603-1615 ISSN 0263-8762 R&D Projects: GA ČR GA13-23046S Institutional support: RVO:61388998 Keywords : fluidic oscillator * microbubble generation * fluidic feedback loop Subject RIV: BK - Fluid Dynamics Impact factor: 2.348, year: 2014 http://dx.doi.org/10.1016/j.cherd.2013.12.004

  14. Microbubbles-Assisted Ultrasound Triggers the Release of Extracellular Vesicles

    Directory of Open Access Journals (Sweden)

    Yuana Yuana

    2017-07-01

    Full Text Available Microbubbles-assisted ultrasound (USMB has shown promise in improving local drug delivery. The formation of transient membrane pores and endocytosis are reported to be enhanced by USMB, and they contribute to cellular drug uptake. Exocytosis also seems to be linked to endocytosis upon USMB treatment. Based on this rationale, we investigated whether USMB triggers exocytosis resulting in the release of extracellular vesicles (EVs. USMB was performed on a monolayer of head-and-neck cancer cells (FaDu with clinically approved microbubbles and commonly used ultrasound parameters. At 2, 4, and 24 h, cells and EV-containing conditioned media from USMB and control conditions (untreated cells, cells treated with microbubbles and ultrasound only were harvested. EVs were measured using flow cytometric immuno-magnetic bead capture assay, immunogold electron microscopy, and western blotting. After USMB, levels of CD9 exposing-EVs significantly increased at 2 and 4 h, whereas levels of CD63 exposing-EVs increased at 2 h. At 24 h, EV levels were comparable to control levels. EVs released after USMB displayed a heterogeneous size distribution profile (30–1200 nm. Typical EV markers CD9, CD63, and alix were enriched in EVs released from USMB-treated FaDu cells. In conclusion, USMB treatment triggers exocytosis leading to the release of EVs from FaDu cells.

  15. Cavitation microstreaming and stress fields created by microbubbles.

    Science.gov (United States)

    Collis, James; Manasseh, Richard; Liovic, Petar; Tho, Paul; Ooi, Andrew; Petkovic-Duran, Karolina; Zhu, Yonggang

    2010-02-01

    Cavitation microstreaming plays a role in the therapeutic action of microbubbles driven by ultrasound, such as the sonoporative and sonothrombolytic phenomena. Microscopic particle-image velocimetry experiments are presented. Results show that many different microstreaming patterns are possible around a microbubble when it is on a surface, albeit for microbubbles much larger than used in clinical practice. Each pattern is associated with a particular oscillation mode of the bubble, and changing between patterns is achieved by changing the sound frequency. Each microstreaming pattern also generates different shear stress and stretch/compression distributions in the vicinity of a bubble on a wall. Analysis of the micro-PIV results also shows that ultrasound-driven microstreaming flows around bubbles are feasible mechanisms for mixing therapeutic agents into the surrounding blood, as well as assisting sonoporative delivery of molecules across cell membranes. Patterns show significant variations around the bubble, suggesting sonoporation may be either enhanced or inhibited in different zones across a cellular surface. Thus, alternating the patterns may result in improved sonoporation and sonothrombolysis. The clear and reproducible delineation of microstreaming patterns based on driving frequency makes frequency-based pattern alternation a feasible alternative to the clinically less desirable practice of increasing sound pressure for equivalent sonoporative or sonothrombolytic effect. Surface divergence is proposed as a measure relevant to sonoporation.

  16. Mediatization

    DEFF Research Database (Denmark)

    Hjarvard, Stig

    2017-01-01

    Mediatization research shares media effects studies' ambition of answering the difficult questions with regard to whether and how media matter and influence contemporary culture and society. The two approaches nevertheless differ fundamentally in that mediatization research seeks answers...... to these general questions by distinguishing between two concepts: mediation and mediatization. The media effects tradition generally considers the effects of the media to be a result of individuals being exposed to media content, i.e. effects are seen as an outcome of mediated communication. Mediatization...... research is concerned with long-term structural changes involving media, culture, and society, i.e. the influences of the media are understood in relation to how media are implicated in social and cultural changes and how these processes come to create new conditions for human communication and interaction...

  17. Magnetic resonance properties of Gd(III)-bound lipid-coated microbubbles and their cavitation fragments.

    Science.gov (United States)

    Feshitan, Jameel A; Boss, Michael A; Borden, Mark A

    2012-10-30

    Gas-filled microbubbles are potentially useful theranostic agents for magnetic resonance imaging-guided focused ultrasound surgery (MRIgFUS). Previously, MRI at 9.4 T was used to measure the contrast properties of lipid-coated microbubbles with gadolinium (Gd(III)) bound to lipid headgroups, which revealed that the longitudinal molar relaxivity (r(1)) increased after microbubble fragmentation. This behavior was attributed to an increase in water proton exchange with the Gd(III)-bound lipid fragments caused by an increase in the lipid headgroup area that accompanied the lipid shell monolayer-to-bilayer transition. In this article, we explore this mechanism by comparing the changes in r(1) and its transverse counterpart, r(2)*, after the fragmentation of microbubbles consisting of Gd(III) bound to two different locations on the lipid monolayer shell: the phosphatidylethanolamine (PE) lipid headgroup region or the distal region of the poly(ethylene glycol) (PEG) brush. Nuclear magnetic resonance (NMR) at 1.5 T was used to measure the contrast properties of the various microbubble constructs because this is the most common field strength used in clinical MRI. Results for the lipid-headgroup-labeled Gd(III) microbubbles revealed that r(1) increased after microbubble fragmentation, whereas r(2)* was unchanged. An analysis of PEG-labeled Gd(III) microbubbles revealed that both r(1) and r(2)* decreased after microbubble fragmentation. Further analysis revealed that the microbubble gas core enhanced the transverse MR signal (T(2)*) in a concentration-dependent manner but minimally affected the longitudinal (T(1)) signal. These results illustrate a new method for the use of NMR to measure the biomembrane packing structure and suggest that two mechanisms, proton-exchange enhancement by lipid membrane relaxation and magnetic field inhomogeneity imposed by the gas/liquid interface, may be used to detect and differentiate Gd(III)-labeled microbubbles and their cavitation

  18. Acoustic Characterization and Enhanced Ultrasound Imaging of Long-Circulating Lipid-Coated Microbubbles.

    Science.gov (United States)

    Li, Hongbo; Yang, Yanye; Zhang, Meimei; Yin, Liping; Tu, Juan; Guo, Xiasheng; Zhang, Dong

    2018-05-01

    A long-circulating lipid-coated ultrasound (US) contrast agent was fabricated to achieve a longer wash-out time and gain more resistance against higher-mechanical index sonication. Systemic physical, acoustic, and in vivo imaging experiments were performed to better understand the underlying mechanism enabling the improvement of contrast agent performance by adjusting the physical and acoustic properties of contrast agent microbubbles. By simply altering the gas core, a kind of US contrast agent microbubble was synthesized with a similar lipid-coating shell as SonoVue microbubbles (Bracco SpA, Milan, Italy) to achieve a longer wash-out time and higher inertial cavitation threshold. To bridge the structure-performance relationship of the synthesized microbubbles, the imaging performance of the microbubbles was assessed in vivo with SonoVue as a control group. The size distribution and inertial cavitation threshold of the synthesized microbubbles were characterized, and the shell parameters of the microbubbles were determined by acoustic attenuation measurements. All of the measurements were compared with SonoVue microbubbles. The synthesized microbubbles had a spherical shape, a smooth, consistent membrane, and a uniform distribution, with an average diameter of 1.484 μm. According to the measured attenuation curve, the synthesized microbubbles resonated at around 2.8 MHz. Although the bubble's shell elasticity (0.2 ± 0.09 N/m) was comparable with SonoVue, it had relatively greater viscosity and inertial cavitation because of the different gas core. Imaging studies showed that the synthesized microbubbles had a longer circulation time and a better chance of fighting against rapid collapse than SonoVue. Nano/micrometer long-circulating lipid-coated microbubbles could be fabricated by simply altering the core composition of SonoVue microbubbles with a higher-molecular weight gas. The smaller diameter and higher inertial cavitation threshold of the

  19. Hysteretic Nonlinearity of Sub-harmonic Emission from Ultrasound Contrast Agent Microbubbles

    International Nuclear Information System (INIS)

    Qiu Yuan-Yuan; Zhang Dong; Zheng Hai-Rong

    2011-01-01

    Sub-harmonic contrast imaging promises to improve ultrasound imaging quality by taking advantage of increased contrast to tissue signal. The aim of this study is to examine the hysteretic nonlinearity of sub-harmonic component emitted from microbubbles. Two kinds of microbubble solutions, i.e. Sonovue® and a self-developed contrast agent, are utilized in the study. The hysteretic curves for increasing and decreasing acoustic pressure are theoretically predicted by the Marmottant model and confirmed by measurements. The results reveal that for both microbubble solutions, the development of the rising ramp undergoes three stages, i.e. occurrence, growth and saturation; while hysteresis effect appears in the descending ramp. Sonovue® microbubbles exhibit better sub-harmonic performance over the self-developed UCAs microbubbles due to the difference of elastic properties of the shell. (fundamental areas of phenomenology(including applications))

  20. Magnetic targeting to enhance microbubble delivery in an occluded microarterial bifurcation.

    Science.gov (United States)

    de Saint Victor, M; Carugo, D; Barnsley, L C; Owen, J; Coussios, C-C; Stride, E

    2017-09-05

    Ultrasound and microbubbles have been shown to accelerate the breakdown of blood clots both in vitro and in vivo. Clinical translation of this technology is still limited, however, in part by inefficient microbubble delivery to the thrombus. This study examines the obstacles to delivery posed by fluid dynamic conditions in occluded vasculature and investigates whether magnetic targeting can improve microbubble delivery. A 2D computational fluid dynamic model of a fully occluded Y-shaped microarterial bifurcation was developed to determine: (i) the fluid dynamic field in the vessel with inlet velocities from 1-100 mm s -1 (corresponding to Reynolds numbers 0.25-25); (ii) the transport dynamics of fibrinolytic drugs; and (iii) the flow behavior of microbubbles with diameters in the clinically-relevant range (0.6-5 µm). In vitro experiments were carried out in a custom-built microfluidic device. The flow field was characterized using tracer particles, and fibrinolytic drug transport was assessed using fluorescence microscopy. Lipid-shelled magnetic microbubbles were fluorescently labelled to determine their spatial distribution within the microvascular model. In both the simulations and experiments, the formation of laminar vortices and an abrupt reduction of fluid velocity were observed in the occluded branch of the bifurcation, severely limiting drug transport towards the occlusion. In the absence of a magnetic field, no microbubbles reached the occlusion, remaining trapped in the first vortex, within 350 µm from the bifurcation center. The number of microbubbles trapped within the vortex decreased as the inlet velocity increased, but was independent of microbubble size. Application of a magnetic field (magnetic flux density of 76 mT, magnetic flux density gradient of 10.90 T m -1 at the centre of the bifurcation) enabled delivery of microbubbles to the occlusion and the number of microbubbles delivered increased with bubble size and with decreasing inlet

  1. Prevalence and clinical significance of pleural microbubbles in computed tomography of thoracic empyema

    International Nuclear Information System (INIS)

    Smolikov, A.; Smolyakov, R.; Riesenberg, K.; Schlaeffer, F.; Borer, A.; Cherniavsky, E.; Gavriel, A.; Gilad, J.

    2006-01-01

    AIM: To determine the prevalence and clinical significance of pleural microbubbles in thoracic empyema. MATERIALS AND METHODS: The charts of 71 consecutive patients with empyema were retrospectively reviewed for relevant demographic, laboratory, microbiological, therapeutic and outcome data. Computed tomography (CT) images were reviewed for various signs of empyema as well as pleural microbubbles. Two patient groups, with and without microbubbles were compared. RESULTS: Mean patient age was 49 years and 72% were males. Microbubbles were detected in 58% of patients. There were no significant differences between patients with and without microbubbles in regard to pleural fluid chemistry. A causative organism was identified in about 75% of cases in both. There was no difference in the rates of pleural thickening and enhancement, increased extra-pleural fat attenuation, air-fluid levels or loculations. Microbubbles were diagnosed after a mean of 7.8 days from admission. Thoracentesis before CT was performed in 90 and 57% of patients with and without microbubbles (p=0.0015), respectively. Patients with microbubbles were more likely to require repeated drainage (65.9 versus 36.7%, p=0.015) and surgical decortication (31.7 versus 6.7%, p=0.011). Mortalities were 9.8 and 6.6% respectively (p=0.53). CONCLUSION: Pleural microbubbles are commonly encountered in CT imaging of empyema but have not been systematically studied to date. Microbubbles may be associated with adverse outcome such as repeated drainage or surgical decortication. The sensitivity and specificity of this finding and its prognostic implications need further assessment

  2. Theranostic Gd(III)-lipid microbubbles for MRI-guided focused ultrasound surgery.

    Science.gov (United States)

    Feshitan, Jameel A; Vlachos, Fotis; Sirsi, Shashank R; Konofagou, Elisa E; Borden, Mark A

    2012-01-01

    We have synthesized a biomaterial consisting of Gd(III) ions chelated to lipid-coated, size-selected microbubbles for utility in both magnetic resonance and ultrasound imaging. The macrocyclic ligand DOTA-NHS was bound to PE headgroups on the lipid shell of pre-synthesized microbubbles. Gd(III) was then chelated to DOTA on the microbubble shell. The reaction temperature was optimized to increase the rate of Gd(III) chelation while maintaining microbubble stability. ICP-OES analysis of the microbubbles determined a surface density of 7.5 × 10(5) ± 3.0 × 10(5) Gd(III)/μm(2) after chelation at 50 °C. The Gd(III)-bound microbubbles were found to be echogenic in vivo during high-frequency ultrasound imaging of the mouse kidney. The Gd(III)-bound microbubbles also were characterized by magnetic resonance imaging (MRI) at 9.4 T by a spin-echo technique and, surprisingly, both the longitudinal and transverse proton relaxation rates were found to be roughly equal to that of no-Gd(III) control microbubbles and saline. However, the relaxation rates increased significantly, and in a dose-dependent manner, after sonication was used to fragment the Gd(III)-bound microbubbles into non-gas-containing lipid bilayer remnants. The longitudinal (r(1)) and transverse (r(2)) molar relaxivities were 4.0 ± 0.4 and 120 ± 18 mM(-1)s(-1), respectively, based on Gd(III) content. The Gd(III)-bound microbubbles may find application in the measurement of cavitation events during MRI-guided focused ultrasound therapy and to track the biodistribution of shell remnants. Copyright © 2011 Elsevier Ltd. All rights reserved.

  3. Destructiveness in Political Discourse

    Directory of Open Access Journals (Sweden)

    Яна Александровна Волкова

    2016-12-01

    Full Text Available Destructiveness is among the fundamental discourse categories that play a significant role in the organization of communicative interaction and define the pragmatics of discourse; its study helps to understand some mechanisms and principles of communication, identify strategies and tactics used by a destructive communicative personality. The relevance of this study is determined by the increasing aggressiveness in various types of discourse, and, accordingly, by the need to extend the knowledge of destructive behavior of a communicative personality. The study is based on the theory of discourse-analysis and theory of destructiveness (Z. Harris, T. van Dijk, A. Buss, E. Fromm, D. Ponton, K. Hacker, R. Wodak. N. Arutyunova, V. Karasik, M. Makarov, E. Sheigal et al. Developing the theory of destructiveness and relying on Erich Fromm’s research (1973, we specify the concept of “destructiveness” in relation to the political discourse and compare it with the related concept of aggressiveness. The paper analyses the category of destructiveness in modern US political discourse, using excerpts from the speeches of the candidates for presidency of 2016. Particular attention is paid to the dominant destructive intention - to harm the reputation of the opponent and reduce his political chances, as well as to the functions of verbal aggression: on the one hand - to discredit the opponent, bring accusations, on the other hand - to poison the audience mind against him/her and arouse the feeling of danger posed by a political opponent. The analysis of verbal and nonverbal means of destructiveness in the US political discourse is carried out. The article concludes that abusive remarks of politicians do not result from spontaneous emotional outburst, but from an elaborated destructive strategy where the agonistic nature of political discourse stipulates the use of instrumental aggression (Buss, 1971 for the sake of the conquest of power, lowering the

  4. Relaxation behavior of a microbubble under ultrasonic field

    International Nuclear Information System (INIS)

    Kang, Sarng Woo; Kwak, Ho Young

    2000-01-01

    Nonlinear oscillation of a microbubble under ultrasound was investigated theoretically. The bubble radius-time curves calculated by the Rayleigh-Plesset equation with a polytropic index and by the Keller-Miksis equation with the analytical solution for the Navier-Stokes equations of the gases were compared with the observed results by the light scattering method. This study has revealed that the bubble behavior such as the expansion ratio and the bouncing motion after the first collapse under ultrasound depends crucially on the retarded time of the bubble motion to the applied ultrasound

  5. Comparison of microbubble presence in the right heart during mechanochemical and radiofrequency ablation for varicose veins.

    Science.gov (United States)

    Moon, K H; Dharmarajah, B; Bootun, R; Lim, C S; Lane, Tra; Moore, H M; Sritharan, K; Davies, A H

    2017-07-01

    Objective Mechanochemical ablation is a novel technique for ablation of varicose veins utilising a rotating catheter and liquid sclerosant. Mechanochemical ablation and radiofrequency ablation have no reported neurological side-effect but the rotating mechanism of mechanochemical ablation may produce microbubbles. Air emboli have been implicated as a cause of cerebrovascular events during ultrasound-guided foam sclerotherapy and microbubbles in the heart during ultrasound-guided foam sclerotherapy have been demonstrated. This study investigated the presence of microbubbles in the right heart during varicose vein ablation by mechanochemical abaltion and radiofrequency abaltion. Methods Patients undergoing great saphenous vein ablation by mechanochemical abaltion or radiofrequency ablation were recruited. During the ablative procedure, the presence of microbubbles was assessed using transthoracic echocardiogram. Offline blinded image quantification was performed using International Consensus Criteria grading guidelines. Results From 32 recruited patients, 28 data sets were analysed. Eleven underwent mechanochemical abaltion and 17 underwent radiofrequency abaltion. There were no neurological complications. In total, 39% (11/28) of patients had grade 1 or 2 microbubbles detected. Thirty-six percent (4/11) of mechanochemical abaltion patients and 29% (5/17) of radiofrequency ablation patients had microbubbles with no significant difference between the groups ( p=0.8065). Conclusion A comparable prevalence of microbubbles between mechanochemical abaltion and radiofrequency ablation both of which are lower than that previously reported for ultrasound-guided foam sclerotherapy suggests that mechanochemical abaltion may not confer the same risk of neurological events as ultrasound-guided foam sclerotherapy for treatment of varicose veins.

  6. On the relationship between microbubble fragmentation, deflation and broadband superharmonic signal production.

    Science.gov (United States)

    Lindsey, Brooks D; Rojas, Juan D; Dayton, Paul A

    2015-06-01

    Acoustic angiography imaging of microbubble contrast agents uses the superharmonic energy produced from excited microbubbles and enables high-contrast, high-resolution imaging. However, the exact mechanism by which broadband harmonic energy is produced is not fully understood. To elucidate the role of microbubble shell fragmentation in superharmonic signal production, simultaneous optical and acoustic measurements were performed on individual microbubbles at transmit frequencies from 1.75 to 3.75 MHz and pressures near the shell fragmentation threshold for microbubbles of varying diameter. High-amplitude, broadband superharmonic signals were produced with shell fragmentation, whereas weaker signals (approximately 25% of peak amplitude) were observed in the presence of shrinking bubbles. Furthermore, when populations of stationary microbubbles were imaged with a dual-frequency ultrasound imaging system, a sharper decline in image intensity with respect to frame number was observed for 1-μm bubbles than for 4-μm bubbles. Finally, in a study of two rodents, increasing frame rate from 4 to 7 Hz resulted in decreases in mean steady-state image intensity of 27% at 1000 kPa and 29% at 1300 kPa. Although the existence of superharmonic signals when bubbles shrink has the potential to prolong the imaging efficacy of microbubbles, parameters such as frame rate and peak pressure must be balanced with expected re-perfusion rate to maintain adequate contrast during in vivo imaging. Copyright © 2015. Published by Elsevier Inc.

  7. Microbubble enhanced ozonation process for advanced treatment of wastewater produced in acrylic fiber manufacturing industry

    KAUST Repository

    Zheng, Tianlong

    2015-02-02

    This work investigated microbubble-ozonation for the treatment of a refractory wet-spun acrylic fiber wastewater in comparison to macrobubble-ozonation. CODcr, NH3-N, and UV254 of the wastewater were removed by 42%, 21%, and 42%, respectively in the microbubble-ozonation, being 25%, 9%, and 35% higher than the removal rates achieved by macrobubble-ozonation at the same ozone dose. The microbubbles (with average diameter of 45μm) had a high concentration of 3.9×105 counts/mL at a gas flow rate of 0.5L/min. The gas holdup, total ozone mass-transfer coefficient, and average ozone utilization efficiency in the microbubble-ozonation were 6.6, 2.2, and 1.5 times higher than those of the macrobubble-ozonation. Greater generation of hydroxyl radicals and a higher zeta potential of the bubbles were also observed in the microbubble ozonation process. The biodegradability of the wastewater was also significantly improved by microbubble-ozonation, which was ascribed to the enhanced degradation of alkanes, aromatic compounds, and the many other bio-refractory organic compounds in the wastewater. Microbubble-ozonation can thus be a more effective treatment process than traditional macrobubble-ozonation for refractory wastewater produced by the acrylic fiber manufacturing industry.

  8. Advanced treatment of acrylic fiber manufacturing wastewater with a combined microbubble-ozonation/ultraviolet irradiation process

    KAUST Repository

    Zheng, Tianlong; Zhang, Tao; Wang, Qunhui; Tian, Yanli; Shi, Zhining; Smale, Nicholas; Xu, Banghua

    2015-01-01

    This work investigated the effectiveness of a combination of microbubble-ozonation and ultraviolet (UV) irradiation for the treatment of secondary wastewater effluent of a wet-spun acrylic fiber manufacturing plant. Under reactor condition (ozone dosage of 48 mg L-1, UV fluence rate of 90 mW cm-2, initial pH of 8.0, and reaction time of 120 min), the biodegradability (represented as BOD5/CODcr) of the wastewater improved from 0.18 to 0.47. This improvement in biodegradability is related to the degradation of alkanes, aromatic compounds, and other bio-refractory organic compounds. The combination of microbubble-ozonation and UV irradiation synergistically improved treatment efficiencies by 228%, 29%, and 142% for CODcr, UV254 removal and BOD5/CODcr respectively after 120 min reaction time, as compared with the sum efficiency of microbubble-ozonation alone and UV irradiation alone. Hydroxyl radical production in the microbubble-ozonation/UV process was about 1.8 times higher than the sum production in microbubble-ozonation alone and UV irradiation alone. The ozone decomposition rate in the combined process was about 4.1 times higher than that in microbubble-ozonation alone. The microbubble-ozonation/UV process could be a promising technique for the treatment of bio-refractory organics in the acrylic fiber manufacturing industry. © 2015 Royal Society of Chemistry.

  9. A novel microbubble construct for intracardiac or intravascular MR manometry: a theoretical study

    International Nuclear Information System (INIS)

    Dharmakumar, Rohan; Plewes, Donald B; Wright, Graham A

    2005-01-01

    It has been demonstrated that gas-filled microbubble contrast agents, based on their volume changes, can serve as pressure probes in an MR field. It was recently reported that such an MR-based pressure measurement with microbubbles at 1.5 T must make use of microbubbles that have a volumetric magnetic susceptibility difference with the blood of at least 34 ppm in SI units. In this work, we show through analytical approximations and numerical simulations that such a microbubble formulation can be achieved by coating typical lipid-shelled microbubbles with particles of high dipole moment. Through finite-element simulations we demonstrate that the effective volumetric magnetic susceptibility of a coated microbubble is dependent on the radius, the shell volume fraction and the magnetic susceptibility of the particulates on the shell. Our calculations suggest that a suitable microbubble formulation which will be MR-sensitive to small pressure changes at 1.5 T must be 2-3 μm in radius and be uniformly coated with single-domain magnetic nanoparticles, such as magnetite, at shell volume fractions below 5%

  10. Size distributions of micro-bubbles generated by a pressurized dissolution method

    Science.gov (United States)

    Taya, C.; Maeda, Y.; Hosokawa, S.; Tomiyama, A.; Ito, Y.

    2012-03-01

    Size of micro-bubbles is widely distributed in the range of one to several hundreds micrometers and depends on generation methods, flow conditions and elapsed times after the bubble generation. Although a size distribution of micro-bubbles should be taken into account to improve accuracy in numerical simulations of flows with micro-bubbles, a variety of the size distribution makes it difficult to introduce the size distribution in the simulations. On the other hand, several models such as the Rosin-Rammler equation and the Nukiyama-Tanazawa equation have been proposed to represent the size distribution of particles or droplets. Applicability of these models to the size distribution of micro-bubbles has not been examined yet. In this study, we therefore measure size distribution of micro-bubbles generated by a pressurized dissolution method by using a phase Doppler anemometry (PDA), and investigate the applicability of the available models to the size distributions of micro-bubbles. Experimental apparatus consists of a pressurized tank in which air is dissolved in liquid under high pressure condition, a decompression nozzle in which micro-bubbles are generated due to pressure reduction, a rectangular duct and an upper tank. Experiments are conducted for several liquid volumetric fluxes in the decompression nozzle. Measurements are carried out at the downstream region of the decompression nozzle and in the upper tank. The experimental results indicate that (1) the Nukiyama-Tanasawa equation well represents the size distribution of micro-bubbles generated by the pressurized dissolution method, whereas the Rosin-Rammler equation fails in the representation, (2) the bubble size distribution of micro-bubbles can be evaluated by using the Nukiyama-Tanasawa equation without individual bubble diameters, when mean bubble diameter and skewness of the bubble distribution are given, and (3) an evaluation method of visibility based on the bubble size distribution and bubble

  11. Effect of microbubble contrast agent during high intensity focused ultrasound ablation on rabbit liver in vivo

    International Nuclear Information System (INIS)

    Chung, Dong Jin; Cho, Se Hyun; Lee, Jae Mun; Hahn, Seong-Tae

    2012-01-01

    Objective: To evaluate the effect of a microbubble contrast agent (SonoVue) during HIFU ablation of a rabbit liver. Materials and methods: HIFU ablations (intensity of 400 W/cm 2 for 4 s, six times, with a 5 s interval between exposures) were performed upon 16 in vivo rabbit livers before and after intravenous injection of a microbubble contrast agent (0.8 ml). A Wilcoxon signed rank test was used to compare mean ablation volume and time required to tissue ablation on real-time US. Shape of ablation and pattern of coagulative necrosis were analyzed by Fisher's exact test. Results: The volume of coagulative necrosis was significantly larger in the combination microbubble and HIFU group than in the HIFU alone group (P < 0.05). Also, time to reach ablation was shorter in the combination microbubble and HIFU group than in the HIFU alone group (P < 0.05). When analyzing the shape of tissue ablation, a pyramidal shape was more prevalently in the HIFU alone group compared to the combination microbubble and HIFU group (P < 0.05). Following an analysis of the pattern of coagulative necrosis, non-cavitary necrosis was found in ten and cavitary necrosis in six of the samples in the combination microbubble and HIFU group. Conversely, non-cavitary necrosis occurred in all 16 samples in the HIFU alone group (P < 0.05). Conclusion: HIFU of in vivo rabbit livers with a microbubble contrast agent produced larger zones of ablation and more cavitary tissue necrosis than without the use of a microbubble contrast agent. Microbubble contrast agents may be useful in tissue ablation by enhancing the treatment effect of HIFU.

  12. Enhanced intracellular delivery of a model drug using microbubbles produced by a microfluidic device.

    Science.gov (United States)

    Dixon, Adam J; Dhanaliwala, Ali H; Chen, Johnny L; Hossack, John A

    2013-07-01

    Focal drug delivery to a vessel wall facilitated by intravascular ultrasound and microbubbles holds promise as a potential therapy for atherosclerosis. Conventional methods of microbubble administration result in rapid clearance from the bloodstream and significant drug loss. To address these limitations, we evaluated whether drug delivery could be achieved with transiently stable microbubbles produced in real time and in close proximity to the therapeutic site. Rat aortic smooth muscle cells were placed in a flow chamber designed to simulate physiological flow conditions. A flow-focusing microfluidic device produced 8 μm diameter monodisperse microbubbles within the flow chamber, and ultrasound was applied to enhance uptake of a surrogate drug (calcein). Acoustic pressures up to 300 kPa and flow rates up to 18 mL/s were investigated. Microbubbles generated by the flow-focusing microfluidic device were stabilized with a polyethylene glycol-40 stearate shell and had either a perfluorobutane (PFB) or nitrogen gas core. The gas core composition affected stability, with PFB and nitrogen microbubbles exhibiting half-lives of 40.7 and 18.2 s, respectively. Calcein uptake was observed at lower acoustic pressures with nitrogen microbubbles (100 kPa) than with PFB microbubbles (200 kPa) (p 3). In addition, delivery was observed at all flow rates, with maximal delivery (>70% of cells) occurring at a flow rate of 9 mL/s. These results demonstrate the potential of transiently stable microbubbles produced in real time and in close proximity to the intended therapeutic site for enhancing localized drug delivery. Copyright © 2013 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  13. Pinched flow fractionation of microbubbles for ultrasound contrast agent enrichment

    Science.gov (United States)

    Versluis, Michel; Kok, Maarten; Segers, Tim

    2014-11-01

    An ultrasound contrast agent (UCA) suspension contains a wide size distribution of encapsulated microbubbles (typically 1-10 μm in diameter) that resonate to the driving ultrasound field by the intrinsic relationship between bubble size and ultrasound frequency. Medical transducers, however, operate in a narrow frequency range, which severely limits the number of bubbles that contribute to the echo signal. Thus, the sensitivity can be improved by narrowing down the size distribution of the bubble suspension. Here, we present a novel, low-cost, lab-on-a-chip method for the sorting of contrast microbubbles by size, based on a microfluidic separation technique known as pinched flow fractionation (PFF). We show by experimental and numerical investigation that the inclusion of particle rotation is essential for an accurate physical description of the sorting behavior of the larger bubbles. Successful sorting of a bubble suspension with a narrow size distribution (3.0 +/- 0.6 μm) has been achieved with a PFF microdevice. This sorting technique can be easily parallelized, and may lead to a significant improvement in the sensitivity of contrast-enhanced medical ultrasound. This work is supported by NanoNextNL, a micro and nanotechnology consortium of the Government of the Netherlands and 130 partners.

  14. Three-Dimensional Phenomena in Microbubble Acoustic Streaming

    Science.gov (United States)

    Marin, Alvaro; Rossi, Massimiliano; Rallabandi, Bhargav; Wang, Cheng; Hilgenfeldt, Sascha; Kähler, Christian J.

    2015-04-01

    Ultrasound-driven oscillating microbubbles are used as active actuators in microfluidic devices to perform manifold tasks such as mixing, sorting, and manipulation of microparticles. A common configuration consists of side bubbles created by trapping air pockets in blind channels perpendicular to the main channel direction. This configuration consists of acoustically excited bubbles with a semicylindrical shape that generate significant streaming flow. Because of the geometry of the channels, such flows are generally considered as quasi-two-dimensional. Similar assumptions are often made in many other microfluidic systems based on flat microchannels. However, in this Letter we show that microparticle trajectories actually present a much richer behavior, with particularly strong out-of-plane dynamics in regions close to the microbubble interface. Using astigmatism particle-tracking velocimetry, we reveal that the apparent planar streamlines are actually projections of a stream surface with a pseudotoroidal shape. We, therefore, show that acoustic streaming cannot generally be assumed as a two-dimensional phenomenon in confined systems. The results have crucial consequences for most of the applications involving acoustic streaming such as particle trapping, sorting, and mixing.

  15. Frequency dependence and frequency control of microbubble streaming flows

    Science.gov (United States)

    Wang, Cheng; Rallabandi, Bhargav; Hilgenfeldt, Sascha

    2013-02-01

    Steady streaming from oscillating microbubbles is a powerful actuating mechanism in microfluidics, enjoying increased use due to its simplicity of manufacture, ease of integration, low heat generation, and unprecedented control over the flow field and particle transport. As the streaming flow patterns are caused by oscillations of microbubbles in contact with walls of the set-up, an understanding of the bubble dynamics is crucial. Here we experimentally characterize the oscillation modes and the frequency response spectrum of such cylindrical bubbles, driven by a pressure variation resulting from ultrasound in the range of 1 kHz raisebox {-.9ex{stackrel{textstyle <}{˜ }} }f raisebox {-.9ex{stackrel{textstyle <}{˜ }} } 100 kHz. We find that (i) the appearance of 2D streaming flow patterns is governed by the relative amplitudes of bubble azimuthal surface modes (normalized by the volume response), (ii) distinct, robust resonance patterns occur independent of details of the set-up, and (iii) the position and width of the resonance peaks can be understood using an asymptotic theory approach. This theory describes, for the first time, the shape oscillations of a pinned cylindrical bubble at a wall and gives insight into necessary mode couplings that shape the response spectrum. Having thus correlated relative mode strengths and observed flow patterns, we demonstrate that the performance of a bubble micromixer can be optimized by making use of such flow variations when modulating the driving frequency.

  16. Bioinspired preparation of alginate nanoparticles using microbubble bursting.

    Science.gov (United States)

    Elsayed, Mohamed; Huang, Jie; Edirisinghe, Mohan

    2015-01-01

    Nanoparticles are considered to be one of the most advanced tools for drug delivery applications. In this research, alginate (a model hydrophilic polymer) nanoparticles 80 to 200 nm in diameter were obtained using microbubble bursting. The natural process of bubble bursting occurs through a number of stages, which consequently produce nano- and microsized droplets via two main production mechanisms, bubble shell disintegration and a jetting process. In this study, nano-sized droplets/particles were obtained by promoting the disintegrating mechanism and suppressing (limiting) the formation of larger microparticles resulting from the jetting mechanism. A T-junction microfluidic device was used to prepare alginate microbubbles with different sizes in a well-controlled manner. The size of the bubbles was varied by controlling two processing parameters, the solution flow rate and the bubbling pressure. Crucially, the bubble size was found to be the determining factor for inducing (or limiting) the bubble shell disintegration mechanism and the size needed to promote this process was influenced by the properties of the solution used for preparing the bubbles, particularly the viscosity. The size of alginate nanoparticles produced via the disintegration mechanism was found to be directly proportional to the viscosity of the alginate solution. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Velocity field measurement in micro-bubble emission boiling

    International Nuclear Information System (INIS)

    Ito, Daisuke; Saito, Yasushi; Natazuka, Jun

    2017-01-01

    Liquid inlet behavior to a heat surface in micro-bubble emission boiling (MEB) was investigated by flow measurement using particle image velocimetry (PIV). Subcooled pool boiling experiments under atmospheric pressure were carried out using a heat surface with a diameter of 10 mm. An upper end of a heater block made of copper was used as the heat surface. Working fluid was the deionized water and the subcooling was varied from 40 K to 70 K. Three K-type thermocouples were installed in the copper block to measure the temperature gradient, and the heat flux and wall superheat were estimated from these temperature data to make a boiling curve. The flow visualization around the heat surface was carried out using a high-speed video camera and a light sheet. The microbubbles generated in the MEB were used as tracer particles and the velocity field was obtained by PIV analysis of the acquired image sequence. As a result, the higher heat fluxes than the critical heat flux could be obtained in the MEB region. In addition, the distribution characteristics of the velocity in MEB region were studied using the PIV results and the location of the stagnation point in the velocity fields was discussed. (author)

  18. Electrochemical destruction of nitrosamines

    Energy Technology Data Exchange (ETDEWEB)

    Lejen, T; Volchek, K; Ladanowski, C; Velicogna, D; Whittaker, H [Environment Canada, Ottawa, ON (Canada). Emergencies Engineering Div.

    1996-09-01

    Treatment conditions for the electrolytic destruction of nitrosamines were studied. The joint investigation between Canada and the Ukraine was part of an assessment of hazardous contaminants at former Soviet ICBM missile sites. The electrochemical destruction of N-dimethylnitrosamines (NDMA) on carbon/platinum electrodes was studied under basic and acidic conditions by UV spectroscopy, gas chromatography, mass spectroscopy, and colorimetry. Experiments with a 100 ppm NDMA solution showed that electrolytic-reduction was pH sensitive within a range of pH 0.5 to 4.0. Electrolysis was effective for the reduction of NDMA in strong acidic conditions. 30 refs., 1 tab., 4 figs.

  19. Money Creation and Destruction

    OpenAIRE

    Faure, Salomon; Gersbach, Hans

    2017-01-01

    We study money creation and destruction in today’s monetary architecture and examine the impact of monetary policy and capital regulation in a general equilibrium setting. There are two types of money created and destructed: bank deposits, when banks grant loans to firms or to other banks and central bank money, when the central bank grants loans to private banks. We show that equilibria yield the first-best level of money creation and lending when prices are flexible, regardless of the monet...

  20. Assessments of Bubble Dynamics Model and Influential Parameters in Microbubble Drag Reduction

    National Research Council Canada - National Science Library

    Skudarnov, P. V; Lin, C. X

    2006-01-01

    .... The effects of mixture density variation, free stream turbulence intensity, free stream velocity, and surface roughness on the microbubble drag reduction were studied using a single phase model based...

  1. A model for an acoustically driven microbubble inside a rigid tube

    KAUST Repository

    Qamar, Adnan; Samtaney, Ravi

    2014-01-01

    A theoretical framework to model the dynamics of acoustically driven microbubble inside a rigid tube is presented. The proposed model is not a variant of the conventional Rayleigh-Plesset category of models. It is derived from the reduced Navier

  2. Microbubbles as contrast agent for in-line x-ray phase-contrast imaging

    International Nuclear Information System (INIS)

    Xi Yan; Zhao Jun; Tang Rongbiao; Wang Yujie

    2011-01-01

    In the present study, we investigated the potential of gas-filled microbubbles as contrast agents for in-line x-ray phase-contrast imaging (PCI) in biomedical applications. When imaging parameters are optimized, the microbubbles function as microlenses that focus the incoming x-rays to form bright spots, which can significantly enhance the image contrast. Since microbubbles have been shown to be safe contrast agents in clinical ultrasonography, this contrast-enhancement procedure for PCI may have promising utility in biomedical applications, especially when the dose of radiation is a serious concern. In this study, we performed both numerical simulations and ex vivo experiments to investigate the formation of the contrast and the effectiveness of microbubbles as contrast agents in PCI.

  3. Stabilization and fabrication of microbubbles: applications for medical purposes and functional materials.

    Science.gov (United States)

    Lee, Mina; Lee, Eun Yeol; Lee, Daeyeon; Park, Bum Jun

    2015-03-21

    Microbubbles with diameters ranging from a few micrometers to tens of micrometers have garnered significant attention in various applications including food processing, water treatment, enhanced oil recovery, surface cleaning, medical purposes, and material preparation fields with versatile functionalities. A variety of techniques have been developed to prepare microbubbles, such as ultrasonication, excimer laser ablation, high shear emulsification, membrane emulsification, an inkjet printing method, electrohydrodynamic atomization, template layer-by-layer deposition, and microfluidics. Generated bubbles should be immediately stabilized via the adsorption of stabilizing materials (e.g., surfactants, lipids, proteins, and solid particles) onto the gas-liquid interface to lower the interfacial tension. Such adsorption of stabilizers prevents coalescence between the microbubbles and also suppresses gas dissolution and resulting disproportionation caused by the presence of the Laplace overpressure across the gas-liquid interface. Herein, we comprehensively review three important topics of microbubbles: stabilization, fabrication, and applications.

  4. Effect of Micro-Bubbles in Water on Beam Patterns of Parametric Array

    Science.gov (United States)

    Hashiba, Kunio; Masuzawa, Hiroshi

    2003-05-01

    The improvement in efficiency of a parametric array by nonlinear oscillation of micro-bubbles in water is studied in this paper. The micro-bubble oscillation can increase the nonlinear coefficient of the acoustic medium. The amplitude of the difference-frequency wave along the longitudinal axis and its beam patterns in the field including the layer with micro-bubbles were analyzed using a Khokhlov-Zabolotskaya-Kuznetsov (KZK) equation. As a result, the largest improvement in efficiency was obtained and a narrow parametric beam was formed by forming a layer with micro-bubbles in front of a parametric sound radiator as thick as about the shock formation distance. If the layer becomes significantly thicker than the distance, the beam of the difference-frequency wave in the far-field will become broader. If the layer is significantly thinner than the distance, the intensity level of the wave in the far-field will be too low.

  5. Multifunctional Polymer Microbubbles for Advanced Sentinel Lymph Node Imaging and Mapping

    Science.gov (United States)

    2012-06-01

    of thiolated poly(acrylic acid) with fluorescein attached. (b) Bright field image of large bubbles stabilized by polymer and phospholipid...Page 1 of 6 AD_________________ Award Number: W81XWH-11-1-0215 TITLE:   Multifunctional Polymer Microbubbles for Advanced... Polymer Microbubbles for Advanced Sentinel Lymph Node Imaging and Mapping 5b. GRANT NUMBER W81XWH-11-1-0215   5c. PROGRAM ELEMENT NUMBER 6

  6. Passive acoustic mapping of magnetic microbubbles for cavitation enhancement and localization

    International Nuclear Information System (INIS)

    Crake, Calum; Victor, Marie de Saint; Owen, Joshua; Coviello, Christian; Collin, Jamie; Coussios, Constantin-C; Stride, Eleanor

    2015-01-01

    Magnetic targeting of microbubbles functionalized with superparamagnetic nanoparticles has been demonstrated previously for diagnostic (B-mode) ultrasound imaging and shown to enhance gene delivery in vitro and in vivo. In the present work, passive acoustic mapping (PAM) was used to investigate the potential of magnetic microbubbles for localizing and enhancing cavitation activity under focused ultrasound. Suspensions of magnetic microbubbles consisting of 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC), air and 10 nm diameter iron oxide nanoparticles were injected into a tissue mimicking phantom at different flow velocities (from 0 to 50 mm s −1 ) with or without an applied magnetic field. Microbubbles were excited using a 500 kHz single element focused transducer at peak negative focal pressures of 0.1–1.0 MPa, while a 64 channel imaging array passively recorded their acoustic emissions. Magnetic localization of microbubble-induced cavitation activity was successfully achieved and could be resolved using PAM as a shift in the spatial distribution and increases in the intensity and sustainability of cavitation activity under the influence of a magnetic field. Under flow conditions at shear rates of up to 100 s −1 targeting efficacy was maintained. Application of a magnetic field was shown to consistently increase the energy of cavitation emissions by a factor of 2–5 times over the duration of exposures compared to the case without targeting, which was approximately equivalent to doubling the injected microbubble dose. These results suggest that magnetic targeting could be used to localize and increase the concentration of microbubbles and hence cavitation activity for a given systemic dose of microbubbles or ultrasound intensity. (paper)

  7. Ultrasound-guided delivery of siRNA and a chemotherapeutic drug by using microbubble complexes: In vitro and in vivo evaluations in a prostate cancer model

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Yun Jung; Yoon, Young Il; Lee, Hak Jong [Dept. of Radiology, Seoul National University Bundang Hospital, Seongnam (Korea, Republic of); Yoon, Tae Jong [Dept. of Applied Bioscience, College of Life Science, CHA University, Pocheon (Korea, Republic of)

    2016-07-15

    To evaluate the effectiveness of ultrasound and microbubble-liposome complex (MLC)-mediated delivery of siRNA and doxorubicin into prostate cancer cells and its therapeutic capabilities both in vitro and in vivo. Microbubble-liposome complexes conjugated with anti-human epidermal growth factor receptor type 2 (Her2) antibodies were developed to target human prostate cancer cell lines PC-3 and LNCaP. Intracellular delivery of MLC was observed by confocal microscopy. We loaded MLC with survivin-targeted small interfering RNA (siRNA) and doxorubicin, and delivered it into prostate cancer cells. The release of these agents was facilitated by ultrasound application. Cell viability was analyzed by MTT assay after the delivery of siRNA and doxorubicin. Survivin-targeted siRNA loaded MLC was delivered into the xenograft mouse tumor model. Western blotting was performed to quantify the expression of survivin in vivo. Confocal microscopy demonstrated substantial intracellular uptake of MLCs in LNCaP, which expresses higher levels of Her2 than PC-3. The viability of LNCaP cells was significantly reduced after the delivery of MLCs loaded with siRNA and doxorubicin (85.0 ± 2.9%), which was further potentiated by application of ultrasound (55.0 ± 3.5%, p = 0.009). Survivin expression was suppressed in vivo in LNCaP tumor xenograft model following the ultrasound and MLC-guided delivery of siRNA (77.4 ± 4.90% to 36.7 ± 1.34%, p = 0.027). Microbubble-liposome complex can effectively target prostate cancer cells, enabling intracellular delivery of the treatment agents with the use of ultrasound. Ultrasound and MLC-mediated delivery of survivin-targeted siRNA and doxorubicin can induce prostate cell apoptosis and block survivin expression in vitro and in vivo.

  8. Ultrasound-Guided Delivery of siRNA and a Chemotherapeutic Drug by Using Microbubble Complexes: In Vitro and In Vivo Evaluations in a Prostate Cancer Model

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Yun Jung [Department of Radiology, Seoul National University Bundang Hospital, Seongnam 13620 (Korea, Republic of); Department of Radiology, Seoul National University College of Medicine, Seoul 03080 (Korea, Republic of); Yoon, Young Il [Department of Radiology, Seoul National University Bundang Hospital, Seongnam 13620 (Korea, Republic of); Department of Radiology, Seoul National University College of Medicine, Seoul 03080 (Korea, Republic of); Program in Nano Science and Technology, Department of Transdisciplinary Studies, Seoul National University Graduate School of Convergence Science and Technology, Suwon 16229 (Korea, Republic of); Yoon, Tae-Jong [Department of Applied Bioscience, College of Life Science, CHA University, Pocheon 11160 (Korea, Republic of); College of Pharmacy, Ajou University, Suwon 16499 (Korea, Republic of); Lee, Hak Jong [Department of Radiology, Seoul National University Bundang Hospital, Seongnam 13620 (Korea, Republic of); Department of Radiology, Seoul National University College of Medicine, Seoul 03080 (Korea, Republic of); Program in Nano Science and Technology, Department of Transdisciplinary Studies, Seoul National University Graduate School of Convergence Science and Technology, Suwon 16229 (Korea, Republic of)

    2016-11-01

    To evaluate the effectiveness of ultrasound and microbubble-liposome complex (MLC)-mediated delivery of siRNA and doxorubicin into prostate cancer cells and its therapeutic capabilities both in vitro and in vivo. Microbubble-liposome complexes conjugated with anti-human epidermal growth factor receptor type 2 (Her2) antibodies were developed to target human prostate cancer cell lines PC-3 and LNCaP. Intracellular delivery of MLC was observed by confocal microscopy. We loaded MLC with survivin-targeted small interfering RNA (siRNA) and doxorubicin, and delivered it into prostate cancer cells. The release of these agents was facilitated by ultrasound application. Cell viability was analyzed by MTT assay after the delivery of siRNA and doxorubicin. Survivin-targeted siRNA loaded MLC was delivered into the xenograft mouse tumor model. Western blotting was performed to quantify the expression of survivin in vivo. Confocal microscopy demonstrated substantial intracellular uptake of MLCs in LNCaP, which expresses higher levels of Her2 than PC-3. The viability of LNCaP cells was significantly reduced after the delivery of MLCs loaded with siRNA and doxorubicin (85.0 ± 2.9%), which was further potentiated by application of ultrasound (55.0 ± 3.5%, p = 0.009). Survivin expression was suppressed in vivo in LNCaP tumor xenograft model following the ultrasound and MLC-guided delivery of siRNA (77.4 ± 4.90% to 36.7 ± 1.34%, p = 0.027). Microbubble-liposome complex can effectively target prostate cancer cells, enabling intracellular delivery of the treatment agents with the use of ultrasound. Ultrasound and MLC-mediated delivery of survivin-targeted siRNA and doxorubicin can induce prostate cell apoptosis and block survivin expression in vitro and in vivo.

  9. Ultrasound-Guided Delivery of siRNA and a Chemotherapeutic Drug by Using Microbubble Complexes: In Vitro and In Vivo Evaluations in a Prostate Cancer Model

    International Nuclear Information System (INIS)

    Bae, Yun Jung; Yoon, Young Il; Yoon, Tae-Jong; Lee, Hak Jong

    2016-01-01

    To evaluate the effectiveness of ultrasound and microbubble-liposome complex (MLC)-mediated delivery of siRNA and doxorubicin into prostate cancer cells and its therapeutic capabilities both in vitro and in vivo. Microbubble-liposome complexes conjugated with anti-human epidermal growth factor receptor type 2 (Her2) antibodies were developed to target human prostate cancer cell lines PC-3 and LNCaP. Intracellular delivery of MLC was observed by confocal microscopy. We loaded MLC with survivin-targeted small interfering RNA (siRNA) and doxorubicin, and delivered it into prostate cancer cells. The release of these agents was facilitated by ultrasound application. Cell viability was analyzed by MTT assay after the delivery of siRNA and doxorubicin. Survivin-targeted siRNA loaded MLC was delivered into the xenograft mouse tumor model. Western blotting was performed to quantify the expression of survivin in vivo. Confocal microscopy demonstrated substantial intracellular uptake of MLCs in LNCaP, which expresses higher levels of Her2 than PC-3. The viability of LNCaP cells was significantly reduced after the delivery of MLCs loaded with siRNA and doxorubicin (85.0 ± 2.9%), which was further potentiated by application of ultrasound (55.0 ± 3.5%, p = 0.009). Survivin expression was suppressed in vivo in LNCaP tumor xenograft model following the ultrasound and MLC-guided delivery of siRNA (77.4 ± 4.90% to 36.7 ± 1.34%, p = 0.027). Microbubble-liposome complex can effectively target prostate cancer cells, enabling intracellular delivery of the treatment agents with the use of ultrasound. Ultrasound and MLC-mediated delivery of survivin-targeted siRNA and doxorubicin can induce prostate cell apoptosis and block survivin expression in vitro and in vivo

  10. Improving ultrasound gene transfection efficiency by controlling ultrasound excitation of microbubbles

    Science.gov (United States)

    Fan, Z.; Chen, D.; Deng, C.X.

    2013-01-01

    Ultrasound application in the presence of microbubbles has shown great potential for non-viral gene transfection via transient disruption of cell membrane (sonoporation). However, improvement of its efficiency has largely relied on empirical approaches without consistent and translatable results. The goal of this study is to develop a rational strategy based on new results obtained using novel experimental techniques and analysis to improve sonoporation gene transfection. We conducted experiments using targeted microbubbles that were attached to cell membrane to facilitate sonoporation. We quantified the dynamic activities of microbubbles exposed to pulsed ultrasound and the resulting sonoporation outcome and identified distinct regimes of characteristic microbubble behaviors: stable cavitation, coalescence and translation, and inertial cavitation. We found that inertial cavitation generated the highest rate of membrane poration. By establishing direct correlation of ultrasound-induced bubble activities with intracellular uptake and pore size, we designed a ramped pulse exposure scheme for optimizing microbubble excitation to improve sonoporation gene transfection. We implemented a novel sonoporation gene transfection system using an aqueous two phase system (ATPS) for efficient use of reagents and high throughput operation. Using plasmid coding for the green fluorescence protein (GFP), we achieved a sonoporation transfection efficiency in rate aortic smooth muscle cells (RASMCs) of 6.9% ± 2.2% (n = 9), comparable with lipofection (7.5% ± 0.8%, n = 9). Our results reveal characteristic microbubble behaviors responsible for sonoporation and demonstrated a rational strategy to improve sonoporation gene transfection. PMID:23770009

  11. Particle migration and sorting in microbubble streaming flows

    Science.gov (United States)

    Thameem, Raqeeb; Hilgenfeldt, Sascha

    2016-01-01

    Ultrasonic driving of semicylindrical microbubbles generates strong streaming flows that are robust over a wide range of driving frequencies. We show that in microchannels, these streaming flow patterns can be combined with Poiseuille flows to achieve two distinctive, highly tunable methods for size-sensitive sorting and trapping of particles much smaller than the bubble itself. This method allows higher throughput than typical passive sorting techniques, since it does not require the inclusion of device features on the order of the particle size. We propose a simple mechanism, based on channel and flow geometry, which reliably describes and predicts the sorting behavior observed in experiment. It is also shown that an asymptotic theory that incorporates the device geometry and superimposed channel flow accurately models key flow features such as peak speeds and particle trajectories, provided it is appropriately modified to account for 3D effects caused by the axial confinement of the bubble. PMID:26958103

  12. Oscillating microbubbles for selective particle sorting in acoustic microfluidic devices

    Science.gov (United States)

    Rogers, Priscilla; Xu, Lin; Neild, Adrian

    2012-05-01

    In this study, acoustic waves were used to excite a microbubble for selective particle trapping and sorting. Excitation of the bubble at its volume resonance, as necessary to drive strong fluid microstreaming, resulted in the particles being either selectively attracted to the bubble or continuing to follow the local microstreamlines. The operating principle exploited two acoustic phenomena acting on the particle suspension: the drag force arising from the acoustic microstreaming and the secondary Bjerknes force, i.e. the attractive radiation force produced between an oscillating bubble and a non-buoyant particle. It was also found that standing wave fields within the fluid chamber could be used to globally align bubbles and particles for local particle sorting by the bubble.

  13. [Relevance of contrast ultrasound with microbubbles in vascular medecine].

    Science.gov (United States)

    Erdmann, Andreas; Ney, Barbara; Alatri, Adriano; Calanca, Luca; Mazzolai, Lucia

    2016-12-07

    Application of ultrasound contrast media has become a standard in diagnostic imaging in cardiology and in the characterization of focal lesions in multiple organs, especially of the liver. In the past years there was a growing body of evidence for their usefulness in vascular medicine. The development of contrast media, microbubbles with a stabilizing envelope and filled with gaz, small enough to pass through pulmonary capillaries made real-time imaging of organ perfusion possible. Ultrasound contrast media are rapidly eliminated by exhalation and can safely be administered to patients with renal failure. The objective of this review is to describe the basic principles of ultrasound contrast imaging and to inform about vascular applications of contrast ultrasound.

  14. Eliminating high-order scattering effects in optical microbubble sizing.

    Science.gov (United States)

    Qiu, Huihe

    2003-04-01

    Measurements of bubble size and velocity in multiphase flows are important in much research and many industrial applications. It has been found that high-order refractions have great impact on microbubble sizing by use of phase-Doppler anemometry (PDA). The problem has been investigated, and a model of phase-size correlation, which also takes high-order refractions into consideration, is introduced to improve the accuracy of bubble sizing. Hence the model relaxes the assumption of a single-scattering mechanism in a conventional PDA system. The results of simulation based on this new model are compared with those based on a single-scattering-mechanism approach or a first-order approach. An optimization method for accurately sizing air bubbles in water has been suggested.

  15. Microbubble drag reduction in liquid turbulent boundary layers

    International Nuclear Information System (INIS)

    Merkle, C.L.; Deutsch, S.

    1992-01-01

    The interactions between a dense cloud of small bubbles and a liquid turbulent boundary layer are reviewed on the basis of available experimental observations to understand and quantify their capability for reducing skin friction. Gas bubbles are generally introduced into the boundary layer by injection through a porous surface or by electrolysis. After injection, the bubbles stay near the wall in boundary-layer-like fashion giving rise to strong gradients in both velocity and gas concentration. In general, the magnitude of the skin friction reduction increases as the volume of bubbles in the boundary layer is increased until a maximum skin friction reduction of typically 80-90% of the undisturbed skin friction level is reached. The volumetric gas flow required for this maximum is nominally equal to the volume flow of the liquid in the boundary layer. Bubble size estimates indicate that in most microbubble experiments the bubbles have been intermediate in size between the inner and outer scales of the undisturbed boundary layer. Additional studies with other nondimensional bubble sizes would be useful. However, the bubble size is most likely controlled by the injection process, and considerably different conditions would be required to change this ratio appreciably. The trajectories of the bubble clouds are primarily determined by the random effects of turbulence and bubble-bubble interactions. The effects of buoyancy represent a weaker effect. The trajectories are unlike the deterministic trajectory of an individual bubble in a time-averaged boundary layer. Bubbles are most effective in high speed boundary layers and, for the bubble sizes tested to date, produce an effect that persists for some on hundred boundary layer thicknesses. Modeling suggests that microbubbles reduce skin friction by increasing the turbulence Reynolds number in the buffer layer in a manner similar to polymers

  16. Non-destructive controls

    International Nuclear Information System (INIS)

    Nouvet, A.

    1978-01-01

    The non-destructive controls permit, while respecting their integrity, the direct and individual examination of parts or complete objects as they are manufactured, as well as to follow the evolution of their eventual defects while in operation. The choice of control methods depends on the manufacturing process and shapes of parts, on the physical properties of their components as well as the nature, position and size of the defects which are likely to be detected. Whether it is a question of controls by means of ionizing radiation, flux of neutrons, ultrasons, acoustic source, sweating, magnetoscopy. Foucault currents, thermography, detection of leaks or non-destructive metallography, each has a limited field of application such that they are less competitive than complementary [fr

  17. Destructive distillation under pressure

    Energy Technology Data Exchange (ETDEWEB)

    1932-09-08

    A process of destructive distillation of distillable carbonaceous material under pressure is described, consisting of regulating the temperature by introducing the carbonaceous materials to a point where the reaction of hydrogenation has begun but has not stopped, by placing it in indirect heat-exchange with a cooling agent at a critical temperature below the reaction temperature, the agent being under pressure and introduced in the liquid state. Water is used as the cooling agent.

  18. Biodistribution, kinetics, and biological fate of SPION microbubbles in the rat

    Directory of Open Access Journals (Sweden)

    Barrefelt A

    2013-08-01

    Full Text Available Åsa Barrefelt,1,2,* Maryam Saghafian,2,* Raoul Kuiper,3 Fei Ye,4 Gabriella Egri,5 Moritz Klickermann,5 Torkel B Brismar,1 Peter Aspelin,1 Mamoun Muhammed,4 Lars Dähne,5 Moustapha Hassan2,6 1Department of Clinical Science, Intervention and Technology, Division of Medical Imaging and Technology, Karolinska Institutet, and Department of Radiology, Karolinska University Hospital-Huddinge, Stockholm, Sweden; 2Experimental Cancer Medicine, Department of Laboratory Medicine, Karolinska Institutet, Stockholm, Sweden; 3Karolinska Institute Core Facility for Morphologic Phenotype Analysis, Clinical Research Center, Karolinska University Hospital-Huddinge, Stockholm, Sweden; 4Division of Functional Materials, Department of Materials and Nano Physics, Royal Institute of Technology, Stockholm, Sweden; 5Surflay Nanotec GmbH, Berlin, Germany; 6Clinical Research Center, Karolinska University Hospital-Huddinge, Stockholm, Sweden *These authors contributed equally to this work Background: In the present investigation, we studied the kinetics and biodistribution of a contrast agent consisting of poly(vinyl alcohol (PVA microbubbles containing superparamagnetic iron oxide (SPION trapped between the PVA layers (SPION microbubbles. Methods: The biological fate of SPION microbubbles was determined in Sprague-Dawley rats after intravenous administration. Biodistribution and elimination of the microbubbles were studied in rats using magnetic resonance imaging for a period of 6 weeks. The rats were sacrificed and perfusion-fixated at different time points. The magnetic resonance imaging results obtained were compared with histopathologic findings in different organs. Results: SPION microbubbles could be detected in the liver using magnetic resonance imaging as early as 10 minutes post injection. The maximum signal was detected between 24 hours and one week post injection. Histopathology showed the presence of clustered SPION microbubbles predominantly in the lungs from

  19. Fabrication and application of a magnetic-targeting and controlled-release system using ST68-based microbubbles

    International Nuclear Information System (INIS)

    Xing Zhanwen; Ke Hengte; Wang Jinrui; Zhao Bo; Qu Enze; Yue Xiuli; Dai Zhifei

    2013-01-01

    Objective: To manufacture magnetic microbubbles with dual-response to ultrasound and magnetic fields. Methods: Microbubbles of ultrasound contrast agent (ST68) based on a surfactant were prepared by the acoustic cavitation method. Fe 3 O 4 magnetic nanoparticles with negative charge were synthesized using the polyol procedure. Magnetic microbubbles were generated by depositing polyethylenimine and Fe 3 O 4 magnetic nanoparticles alternately onto the microbubbles using the layer-by-layer self-assembly. In vitro ultrasonography was performed on a silicone tube with/without magnetic microbubbles (3 × 10 8 /ml) by a self-made device to observe the movement of magnetic microbubbles under the effects of magnetic field. In vivo imaging was performed on the kidney of New Zealand rabbits before and after the injection of magnetic microbubbles. Results: The Fe 3 O 4 nanoparticles carried a stable negative charge of (-24.6 ± 6.7) mV and more than 98% of the particles were less than 8 μm in diameter, meeting the size requirement of an ultrasound contrast agent for intravenous administration. There was no echoic signal in the silicone tube before injection of magnetic microbubbles, but there were strong echoic signals after injection. After applying a magnetic field, the magnetic microbubbles moved along the direction of the magnetic flux. In vivo ultrasound imaging could not visualize the kidney before injection of magnetic microbubbles, but could remarkably visualize the kidney after injection. Conclusions: The magnetic microbubbles exhibit favorable magnetic targeting and ultrasound contrast enhancement characteristics. Such properties may serve as the foundation to study their potential for simultaneous diagnosis and treatment in the future. (authors)

  20. Low temperature destructive distillation

    Energy Technology Data Exchange (ETDEWEB)

    1938-07-05

    A process is given and apparatus is described for the destructive distillation at low temperature of coal, oil shale, and the like by subjection to the action of a stream of hot gases or superhearted steam, flowing in a closed circuit. Subsequent treatment of the distillation residues with a gas stream containing oxygen results in combustion of the carbon-containing material therein brings to a high temperature the solid residue, in which the process comprises subsequently contacting the hot solid residue with the fluid stream effecting the distillation.

  1. The inhibitory receptor FcgammaRII reduces joint inflammation and destruction in experimental immune complex-mediated arthritides not only by inhibition of FcgammaRI/III but also by efficient clearance and endocytosis of immune complexes.

    NARCIS (Netherlands)

    Lent, P.L.E.M. van; Nabbe, K.C.A.M.; Boross, P.; Blom, A.B.; Roth, J.; Holthuysen, A.E.M.; Sloetjes, A.W.; Verbeek, S.; Berg, W.B. van den

    2003-01-01

    Studies of FcgammaRII-/- mice identified the inhibitory function of this receptor in joint inflammation and cartilage destruction induced with immune complexes (ICs). To extend our insight in the role of FcgammaRII in arthritis, we explored the role of FcgammaRII in the absence of activating

  2. Coordinate expression of activating Fc gamma receptors I and III and inhibiting Fc gamma receptor type II in the determination of joint inflammation and cartilage destruction during immune complex-mediated arthritis.

    NARCIS (Netherlands)

    Nabbe, K.C.A.M.; Blom, A.B.; Holthuysen, A.E.M.; Boross, P.; Roth, J.; Verbeek, S.; Lent, P.L.E.M. van; Berg, W.B. van den

    2003-01-01

    OBJECTIVE: To study the role of the activating Fc gamma receptor types I and III (Fc gamma RI and Fc gamma RIII, respectively) and the inhibiting Fc gamma receptor II (Fc gamma RII) in inflammation and in various aspects of cartilage destruction during arthritis that is solely induced by immune

  3. Ultrasonic microbubble contrast agents and the transplant kidney

    Energy Technology Data Exchange (ETDEWEB)

    Kay, D.H., E-mail: davidhkay@doctors.org.u [Department of Radiology, Western Infirmary, Glasgow (United Kingdom); Mazonakis, M.; Geddes, C. [Department of Renal Medicine, Western Infirmary, Glasgow (United Kingdom); Baxter, G. [Department of Radiology, Western Infirmary, Glasgow (United Kingdom)

    2009-11-15

    Aim: To evaluate the potential application of microbubble agents in the immediate post-transplant period, by studying contrast uptake and washout, and to correlate these values with clinical indices, and thus, assess the potential prognostic value of this technique. Materials and methods: The study group comprised 20 consecutive renal transplant patients within 7 days of transplantation. Sonovue was administered as an intravenous bolus with continuous imaging of the transplant kidney at low mechanical index (MI) for 1 min post-injection. These data were analysed off-line by two observers, and time intensity curves (TIC) for the upper, mid, and lower poles constructed. Within each pole, a region of interest (5 mm square) was placed over the cortex, medullary pyramid, and interlobar artery, resulting in a total of nine TIC for each patient. TIC parameters included the arrival time (AT), time to peak (TTP), peak intensity (Max), gradient of the slope (M), and the area under curve (AUC). Results: For both observers there was good agreement for all values measured from the cortex and medulla, but poor interobserver correlation for the vascular values. In addition, there was only agreement for these values in the upper and mid-pole of the transplant with poor agreement for the lower pole values. The mid-pole of the transplant kidney was chosen as the point of measurement for subsequent studies. Mid-pole values were correlated with clinical data and outcome over the 3-month post-transplant period. Renal microbubble perfusion correlated with the transplant estimated glomerular filtration rate (eGFR) at 3 months post-transplantation (p = 0.016). Discussion: In conclusion, this is the first study to confirm reproducibility of the Sonovue TIC data in transplant patients and to quantify regional variation and perfusion. The statistically significant estimates of transplant perfusion may be of future benefit to transplant recipients and potentially utilized as a prognostic tool

  4. Buoyancy-activated cell sorting using targeted biotinylated albumin microbubbles.

    Directory of Open Access Journals (Sweden)

    Yu-Ren Liou

    Full Text Available Cell analysis often requires the isolation of certain cell types. Various isolation methods have been applied to cell sorting, including fluorescence-activated cell sorting and magnetic-activated cell sorting. However, these conventional approaches involve exerting mechanical forces on the cells, thus risking cell damage. In this study we applied a novel isolation method called buoyancy-activated cell sorting, which involves using biotinylated albumin microbubbles (biotin-MBs conjugated with antibodies (i.e., targeted biotin-MBs. Albumin MBs are widely used as contrast agents in ultrasound imaging due to their good biocompatibility and stability. For conjugating antibodies, biotin is conjugated onto the albumin MB shell via covalent bonds and the biotinylated antibodies are conjugated using an avidin-biotin system. The albumin microbubbles had a mean diameter of 2 μm with a polydispersity index of 0.16. For cell separation, the MDA-MB-231 cells are incubated with the targeted biotin-MBs conjugated with anti-CD44 for 10 min, centrifuged at 10 g for 1 min, and then allowed 1 hour at 4 °C for separation. The results indicate that targeted biotin-MBs conjugated with anti-CD44 antibodies can be used to separate MDA-MB-231 breast cancer cells; more than 90% of the cells were collected in the MB layer when the ratio of the MBs to cells was higher than 70:1. Furthermore, we found that the separating efficiency was higher for targeted biotin-MBs than for targeted avidin-incorporated albumin MBs (avidin-MBs, which is the most common way to make targeted albumin MBs. We also demonstrated that the recovery rate of targeted biotin-MBs was up to 88% and the sorting purity was higher than 84% for a a heterogenous cell population containing MDA-MB-231 cells (CD44(+ and MDA-MB-453 cells (CD44-, which are classified as basal-like breast cancer cells and luminal breast cancer cells, respectively. Knowing that the CD44(+ is a commonly used cancer

  5. Microbubble-based fiber-optic Fabry-Perot pressure sensor for high-temperature application.

    Science.gov (United States)

    Li, Zhe; Jia, Pinggang; Fang, Guocheng; Liang, Hao; Liang, Ting; Liu, Wenyi; Xiong, Jijun

    2018-03-10

    Using arc discharge technology, we fabricated a fiber-optic Fabry-Perot (FP) pressure sensor with a very low temperature coefficient based on a microbubble that can be applied in a high-temperature environment. The thin-walled microbubble can be fabricated by heating the gas-pressurized hollow silica tube (HST) using a commercial fusion splicer. Then, the well-cut single-mode fiber (SMF) was inserted into the microbubble, and they were fused together. Thus, the FP cavity can be formed between the end of the SMF and the inner surface of the microbubble. The diameter of the microbubble can be up to 360 μm with the thickness of the wall being approximately 0.5 μm. Experimental results show that such a sensor has a linear sensitivity of approximately -6.382  nm/MPa, -5.912  nm/MPa at 20°C, and 600°C within the pressure range of 1 MPa. Due to the thermal expansion coefficient of the SMF being slightly larger than that of silica, we can fuse the SMF and the HST with different lengths; thus, the sensor has a very low temperature coefficient of approximately 0.17 pm/°C.

  6. Drag reduction mechanism by microbubble injection within a channel boundary layer

    International Nuclear Information System (INIS)

    Ling Zhen; Hassan, Y.

    2005-01-01

    In this study, the drag reduction due to microbubble injection in the boundary layer of a fully developed turbulent channel flow was investigated. Particle Image Velocimetry (PIV) techniques were taken. The effects of the presence of microbubbles in the boundary layer were assessed. A drag reduction of 38.4% was obtained with void fraction of 4.9%. The algorithms of wavelet auto-correlation maps were applied to the PIV velocity field measurement. Modifications in the wavelet auto-correlation maps due to the presence of microbubbles were studied and compared in three-dimensions. By using 3-D plotting routines and the wavelet auto-correlation maps, it can be deduced from this study that the microbubble injection within the boundary layer increases the turbulent energy of the streamwise velocity components of the large scale (large eddy size, low frequency) range and decreases the energy of the small scale (small eddy size, high frequency) range. The wavelet auto-correlation maps of the normal velocities indicate that the microbubble presence decrease the turbulent energy of normal velocity components for both the large scale (large eddy size, low frequency) and the small scale (small eddy size, high frequency) ranges. (authors)

  7. Microbubbles induce renal hemorrhage when exposed to diagnostic ultrasound in anesthetized rats.

    Science.gov (United States)

    Wible, James H; Galen, Karen P; Wojdyla, Jolette K; Hughes, Michael S; Klibanov, Alexander L; Brandenburger, Gary H

    2002-01-01

    The generation of ultrasound (US) bioeffects using a clinical imaging system is controversial. We tested the hypothesis that the presence of microbubbles in the US field of a medical imager induces biologic effects. Both kidneys of anesthetized rats were insonified for 5 min using a medical imaging system after the administration of microbubbles. One kidney was insonified using a continuous mode (30 Hz) and the opposite kidney was insonified using an intermittent (1 Hz) technique. The microbubbles were exposed to three different transducer frequencies and four transducer output powers. After insonification, the animals were euthanized, the kidneys were removed and their gross appearance scored under "blinded" conditions using a defined scale. After the administration of microbubbles, US imaging of the kidney caused hemorrhage in the renal tissue. The severity and area of hemorrhage increased with an increase in the transducer power and a decrease in the transducer frequency. Intermittent insonification in the presence of microbubbles produced a greater degree of renal hemorrhage than continuous imaging techniques.

  8. Enhancing surface methane fluxes from an oligotrophic lake: exploring the microbubble hypothesis.

    Science.gov (United States)

    McGinnis, Daniel F; Kirillin, Georgiy; Tang, Kam W; Flury, Sabine; Bodmer, Pascal; Engelhardt, Christof; Casper, Peter; Grossart, Hans-Peter

    2015-01-20

    Exchange of the greenhouse gases carbon dioxide (CO2) and methane (CH4) across inland water surfaces is an important component of the terrestrial carbon (C) balance. We investigated the fluxes of these two gases across the surface of oligotrophic Lake Stechlin using a floating chamber approach. The normalized gas transfer rate for CH4 (k600,CH4) was on average 2.5 times higher than that for CO2 (k600,CO2) and consequently higher than Fickian transport. Because of its low solubility relative to CO2, the enhanced CH4 flux is possibly explained by the presence of microbubbles in the lake’s surface layer. These microbubbles may originate from atmospheric bubble entrainment or gas supersaturation (i.e., O2) or both. Irrespective of the source, we determined that an average of 145 L m(–2) d(–1) of gas is required to exit the surface layer via microbubbles to produce the observed elevated k600,CH4. As k600 values are used to estimate CH4 pathways in aquatic systems, the presence of microbubbles could alter the resulting CH4 and perhaps C balances. These microbubbles will also affect the surface fluxes of other sparingly soluble gases in inland waters, including O2 and N2.

  9. Micro-bubble generated by laser irradiation on an individual carbon nanocoil

    International Nuclear Information System (INIS)

    Sun, Yanming; Pan, Lujun; Liu, Yuli; Sun, Tao

    2015-01-01

    Highlights: • We have investigated laser irradiated microbubbles which can be generated at fixed point on surface of an individual carbon nanocoil (CNC) immerged in deionized water. • The microbubble can be operated easily and flexibly. • Based on classical heat and mass transfer theories, the bubble growth data is in good agreement with the simplified model. - Abstract: We have investigated the micro-bubbles generated by laser induction on an individual carbon nanocoil (CNC) immerged in deionized water. The photon energy of the incident focused laser beam is absorbed by CNC and converted to thermal energy, which efficiently vaporizes the surrounding water, and subsequently a micro-bubble is generated at the laser location. The dynamics behavior of bubble generation, including its nucleation, expansion and steady-state, has been studied experimentally and theoretically. We have derived equations to analyze the expansion process of a bubble based on classical heat and mass transfer theories. The conclusion is in good agreement with the experiment. CNC, which acts as a realistic micro-bubble generator, can be operated easily and flexibly

  10. Hydrostatic Pressurization of Lung Surfactant Microbubbles: Observation of a Strain-Rate Dependent Elasticity.

    Science.gov (United States)

    Thomas, Alec N; Borden, Mark A

    2017-11-28

    The microbubble offers a unique platform to study lung surfactant mechanics at physiologically relevant geometry and length scale. In this study, we compared the response of microbubbles (∼15 μm initial radius) coated with pure dipalmitoyl-phosphatidylcholine (DPPC) versus naturally derived lung surfactant (SURVANTA) when subjected to linearly increasing hydrostatic pressure at different rates (0.5-2.3 kPa/s) at room temperature. The microbubbles contained perfluorobutane gas and were submerged in buffered saline saturated with perfluorobutane at atmospheric pressure. Bright-field microscopy showed that DPPC microbubbles compressed spherically and smoothly, whereas SURVANTA microbubbles exhibited wrinkling and smoothing cycles associated with buckling and collapse. Seismograph analysis showed that the SURVANTA collapse amplitude was constant, but the collapse rate increased with the pressurization rate. An analysis of the pressure-volume curves indicated that the dilatational elasticity increased during compression for both shell types. The initial dilatational elasticity for SURVANTA was nearly twice that of DPPC at higher pressurization rates (>1.5 kPa/s), producing a pressure drop of up to 60 kPa across the film prior to condensation of the perfluorobutane core. The strain-rate dependent stiffening of SURVANTA shells likely arises from their composition and microstructure, which provide enhanced in-plane monolayer rigidity and lateral repulsion from surface-associated collapse structures. Overall, these results provide new insights into lung surfactant mechanics and collapse behavior during compression.

  11. Microfluidics-based microbubbles in methylene blue solution for photoacoustic and ultrasound imaging

    Science.gov (United States)

    Das, Dhiman; Sivasubramanian, Kathyayini; Yang, Chun; Pramanik, Manojit

    2018-02-01

    Contrast agents which can be used for more than one bio-imaging technique has gained a lot of attention from researchers in recent years. In this work, a microfluidic device employing a flow-focusing junction, is used for the continuous generation of monodisperse nitrogen microbubbles in methylene blue, an optically absorbing organic dye, for dual-modal photoacoustic and ultrasound imaging. Using an external phase of polyoxyethylene glycol 40 stearate (PEG 40), a non-ionic surfactant, and 50% glycerol solution at a flow rate of 1 ml/hr and gas pressure at 1.75 bar, monodisperse nitrogen microbubbles of diameter 7 microns were obtained. The external phase also contained methylene blue hydrate at a concentration of 1 gm/litre. The monodisperse microbubbles produced a strong ultrasound signal as expected. It was observed that the signal-to-noise (SNR) ratio of the photoacoustic signal for the methylene blue solution in the presence of the monodisperse microbubbles was 68.6% lower than that of methylene blue solution in the absence of microbubbles. This work is of significance because using microfluidics, we can precisely control the bubbles' production rate and bubble size which increases ultrasound imaging efficiency. A uniform size distribution of the bubbles will have narrower resonance frequency bandwidth which will respond well to specific ultrasound frequencies.

  12. Fluid Viscosity Affects the Fragmentation and Inertial Cavitation Threshold of Lipid-Encapsulated Microbubbles.

    Science.gov (United States)

    Helfield, Brandon; Black, John J; Qin, Bin; Pacella, John; Chen, Xucai; Villanueva, Flordeliza S

    2016-03-01

    Ultrasound and microbubble optimization studies for therapeutic applications are often conducted in water/saline, with a fluid viscosity of 1 cP. In an in vivo context, microbubbles are situated in blood, a more viscous fluid (∼4 cP). In this study, ultrahigh-speed microscopy and passive cavitation approaches were employed to investigate the effect of fluid viscosity on microbubble behavior at 1 MHz subject to high pressures (0.25-2 MPa). The propensity for individual microbubble (n = 220) fragmentation was found to significantly decrease in 4-cP fluid compared with 1-cP fluid, despite achieving similar maximum radial excursions. Microbubble populations diluted in 4-cP fluid exhibited decreased wideband emissions (up to 10.2 times), and increasingly distinct harmonic emission peaks (e.g., ultraharmonic) with increasing pressure, compared with those in 1-cP fluid. These results suggest that in vitro studies should consider an evaluation using physiologic viscosity perfusate before transitioning to in vivo evaluations. Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  13. Fluid viscosity affects the fragmentation and inertial cavitation threshold of lipid encapsulated microbubbles

    Science.gov (United States)

    Helfield, Brandon; Black, John J.; Qin, Bin; Pacella, John; Chen, Xucai; Villanueva, Flordeliza S.

    2015-01-01

    Ultrasound and microbubble optimization studies for therapeutic applications are often conducted in water/saline, with a fluid viscosity of 1 cP. In an in vivo context, microbubbles are situated in blood, a more viscous fluid (~4 cP). In this study, ultra-high speed microscopy and passive cavitation approaches were employed to investigate the effect of fluid viscosity on microbubble behavior at 1 MHz subject to high pressures (0.25 – 2 MPa). The propensity for individual microbubble (n=220) fragmentation was shown to significantly decrease in 4 cP fluid as compared to 1 cP fluid, despite achieving similar maximum radial excursions. Microbubble populations diluted in 4 cP fluid exhibited decreased wideband emissions (up to 10.2 times), and increasingly distinct harmonic emission peaks (e.g. ultraharmonic) with increasing pressure as compared to 1 cP fluid. These results suggest that in vitro studies should consider an evaluation using physiologic viscosity perfusate before transitioning to in vivo evaluations. PMID:26674676

  14. Algae separation from urban landscape water using a high density microbubble layer enhanced by micro-flocculation.

    Science.gov (United States)

    Chen, Shuwen; Xu, Jingcheng; Liu, Jia; Wei, Qiaoling; Li, Guangming; Huang, Xiangfeng

    2014-01-01

    Eutrophication of raw water results in outbreaks of algae, which hinders conventional water treatment. In this study, high density microbubble layers combined with micro-flocculation was adopted to remove algae from urban landscape water, and the effects of pressure, hydraulic loading, microbubble layer height and flocculation dosage on the removal efficiency for algae were studied. The greatest removal efficiency for algae, chemical oxygen demand, nitrogen and phosphorus was obtained at 0.42 MPa with hydraulic loading at 5 m/h and a flocculation dosage of 4 mg/L using a microbubble layer with a height of 130 cm. Moreover, the size, clearance distance and concentration of microbubbles were found to be affected by pressure and the height of the microbubble layer. Based on the study, this method was an alternative for algae separation from urban landscape water and water purification.

  15. Optical micro-bubble resonators as promising biosensors

    Science.gov (United States)

    Giannetti, A.; Barucci, A.; Berneschi, S.; Cosci, A.; Cosi, F.; Farnesi, D.; Nunzi Conti, G.; Pelli, S.; Soria, S.; Tombelli, S.; Trono, C.; Righini, G. C.; Baldini, F.

    2015-05-01

    Recently, optical micro-bubble resonators (OMBRs) have gained an increasing interest in many fields of photonics thanks to their particular properties. These hollow microstructures can be suitable for the realization of label - free optical biosensors by combining the whispering gallery mode (WGM) resonator properties with the intrinsic capability of integrated microfluidics. In fact, the WGMs are morphology-dependent modes: any change on the OMBR inner surface (due to chemical and/or biochemical binding) causes a shift of the resonance position and reduces the Q factor value of the cavity. By measuring this shift, it is possible to obtain information on the concentration of the analyte to be detected. A crucial step for the development of an OMBR-based biosensor is constituted by the functionalization of its inner surface. In this work we report on the development of a physical and chemical process able to guarantee a good homogeneity of the deposed bio-layer and, contemporary, to preserve a high quality factor Q of the cavity. The OMBR capability of working as bioassay was proved by different optical techniques, such as the real time measurement of the resonance broadening after each functionalization step and fluorescence microscopy.

  16. Optimized open-flow mixing: insights from microbubble streaming

    Science.gov (United States)

    Rallabandi, Bhargav; Wang, Cheng; Guo, Lin; Hilgenfeldt, Sascha

    2015-11-01

    Microbubble streaming has been developed into a robust and powerful flow actuation technique in microfluidics. Here, we study it as a paradigmatic system for microfluidic mixing under a continuous throughput of fluid (open-flow mixing), providing a systematic optimization of the device parameters in this practically important situation. Focusing on two-dimensional advective stirring (neglecting diffusion), we show through numerical simulation and analytical theory that mixing in steady streaming vortices becomes ineffective beyond a characteristic time scale, necessitating the introduction of unsteadiness. By duty cycling the streaming, such unsteadiness is introduced in a controlled fashion, leading to exponential refinement of the advection structures. The rate of refinement is then optimized for particular parameters of the time modulation, i.e. a particular combination of times for which the streaming is turned ``on'' and ``off''. The optimized protocol can be understood theoretically using the properties of the streaming vortices and the throughput Poiseuille flow. We can thus infer simple design principles for practical open flow micromixing applications, consistent with experiments. Current Address: Mechanical and Aerospace Engineering, Princeton University.

  17. Three-dimensional features on oscillating microbubbles streaming flows

    Science.gov (United States)

    Rossi, Massimiliano; Marin, Alvaro G.; Wang, Cheng; Hilgenfeldt, Sascha; Kähler, Christian J.

    2013-11-01

    Ultrasound-driven oscillating micro-bubbles have been used as active actuators in microfluidic devices to perform manifold tasks such as mixing, sorting and manipulation of microparticles. A common configuration consists in side-bubbles, created by trapping air pockets in blind channels perpendicular to the main channel direction. This configuration results in bubbles with a semi-cylindrical shape that creates a streaming flow generally considered quasi two-dimensional. However, recent experiments performed with three-dimensional velocimetry methods have shown how microparticles can present significant three-dimensional trajectories, especially in regions close to the bubble interface. Several reasons will be discussed such as boundary effects of the bottom/top wall, deformation of the bubble interface leading to more complex vibrational modes, or bubble-particle interactions. In the present investigation, precise measurements of particle trajectories close to the bubble interface will be performed by means of 3D Astigmatic Particle Tracking Velocimetry. The results will allow us to characterize quantitatively the three-dimensional features of the streaming flow and to estimate its implications in practical applications as particle trapping, sorting or mixing.

  18. Micro-bubble morphologies following drop impacts onto a pool surface

    KAUST Repository

    Thoroddsen, Sigurdur T; Thoraval, M.-J.; Takehara, K.; Etoh, T.G.

    2012-01-01

    When a drop impacts at low velocity onto a pool surface, a hemispheric air layer cushions and can delay direct contact. Herein we use ultra-high-speed video to study the rupture of this layer, to explain the resulting variety of observed distribution of bubbles. The size and distribution of micro-bubbles is determined by the number and location of the primary punctures. Isolated holes lead to the formation of bubble necklaces when the edges of two growing holes meet, whereas bubble nets are produced by regular shedding of micro-bubbles from a sawtooth edge instability. For the most viscous liquids the air film contracts more rapidly than the capillary-viscous velocity through repeated spontaneous ruptures of the edge. From the speed of hole opening and the total volume of micro-bubbles we conclude that the air sheet ruptures when its thickness approaches ?100.

  19. Micro-bubble morphologies following drop impacts onto a pool surface

    KAUST Repository

    Thoroddsen, Sigurdur T.

    2012-10-01

    When a drop impacts at low velocity onto a pool surface, a hemispheric air layer cushions and can delay direct contact. Herein we use ultra-high-speed video to study the rupture of this layer, to explain the resulting variety of observed distribution of bubbles. The size and distribution of micro-bubbles is determined by the number and location of the primary punctures. Isolated holes lead to the formation of bubble necklaces when the edges of two growing holes meet, whereas bubble nets are produced by regular shedding of micro-bubbles from a sawtooth edge instability. For the most viscous liquids the air film contracts more rapidly than the capillary-viscous velocity through repeated spontaneous ruptures of the edge. From the speed of hole opening and the total volume of micro-bubbles we conclude that the air sheet ruptures when its thickness approaches ?100.

  20. Pancreatic cancer cell detection by targeted lipid microbubbles and multiphoton imaging

    Science.gov (United States)

    Cromey, Benjamin; McDaniel, Ashley; Matsunaga, Terry; Vagner, Josef; Kieu, Khanh Quoc; Banerjee, Bhaskar

    2018-04-01

    Surgical resection of pancreatic cancer represents the only chance of cure and long-term survival in this common disease. Unfortunately, determination of a cancer-free margin at surgery is based on one or two tiny frozen section biopsies, which is far from ideal. Not surprisingly, cancer is usually left behind and is responsible for metastatic disease. We demonstrate a method of receptor-targeted imaging using peptide ligands, lipid microbubbles, and multiphoton microscopy that could lead to a fast and accurate way of examining the entire cut surface during surgery. Using a plectin-targeted microbubble, we performed a blinded in-vitro study to demonstrate avid binding of targeted microbubbles to pancreatic cancer cells but not noncancerous cell lines. Further work should lead to a much-needed point-of-care diagnostic test for determining clean margins in oncologic surgery.

  1. Transit of micro-bubbles through the pulmonary circulation of Thoroughbred horses during exercise.

    Science.gov (United States)

    La Gerche, A; Daffy, J R; Mooney, D J; Forbes, G; Davie, A J

    2013-10-01

    It has been observed that microbubbles may pass through the pulmonary circulation of dogs and humans during exercise. In humans, this phenomenon has been associated with lower pulmonary artery pressures, enhanced right ventricular function and greater exercise capacity. In the exercising Thoroughbred horse, extraordinarily high cardiac outputs exert significant pulmonary vascular stresses. The aim of this study was to determine, using contrast echocardiography, whether Thoroughbred horses performing strenuous exercise developed pulmonary transit of agitated contrast microbubbles (PTAC). At rest, agitated contrast was observed in the right ventricle, but not in the left ventricle. However, post-exercise microbubbles were observed in the left ventricle, confirming the occurrence of PTAC with exercise but not at rest. Further investigation is warranted to investigate whether this phenomenon may be associated with superior physiology and performance measures as has been implicated in other species. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Alkali cyanides; destructive distillation

    Energy Technology Data Exchange (ETDEWEB)

    Clancy, J C

    1925-12-02

    The destructive distillation of carbonaceous substances can be accomplished by heating them in a bath of molten alkali and cyanide. Liquid hydrocarbons are produced. The separation of the cyanide from the coke or carbonaceous residues by filtration leaves a substantial quantity of cyanide absorbed by the carbon. A feasible method for removal has been developed by mixing the mixture of cyanide and coke with sodium carbonate or other alkali in the molten state, then treating this substance with nitrogen with or without ammonia to convert most of the carbon to cyanide. The carbonaceous material may be mixed with a liquid hydrocarbon such as petroleum, shale oil, or heavy tar oil, heated, and introduced below the surface of the liquid cyanide which partially decomposes and hydrogenates the coal to increase the yield of hydrocarbons. Dry ammonia may be bubbled through the reaction mixture to effect agitation and to form more cyanide.

  3. Destructive distillation: oils

    Energy Technology Data Exchange (ETDEWEB)

    West, J; Glover, S

    1918-01-31

    Canned and other coals are destructively distilled in continuously operated vertical retorts which at their upper portions are maintained at temperatures suitable for low temperature oil distillation such as about 700/sup 0/C, and at their lower portions the temperature is higher and such as to be suitable for the production of gas, e.g., about 1400/sup 0/C. Superheated steam is introduced into the lower portion of the retort, preferably by means of the arrangement described in Specification 120,458, and this is converted into blue water gas which assists the distillation in the center of the coal charge. The retorts are preferably such as are described in Specifications 2663/07 and 7757/14.

  4. Improving ultrasound gene transfection efficiency by controlling ultrasound excitation of microbubbles.

    Science.gov (United States)

    Fan, Z; Chen, D; Deng, C X

    2013-09-28

    Ultrasound application in the presence of microbubbles has shown great potential for non-viral gene transfection via transient disruption of cell membrane (sonoporation). However, improvement of its efficiency has largely relied on empirical approaches without consistent and translatable results. The goal of this study is to develop a rational strategy based on new results obtained using novel experimental techniques and analysis to improve sonoporation gene transfection. In this study, we conducted experiments using targeted microbubbles that were attached to cell membrane to facilitate sonoporation. We quantified the dynamic activities of microbubbles exposed to pulsed ultrasound and the resulting sonoporation outcome, and identified distinct regimes of characteristic microbubble behaviors: stable cavitation, coalescence and translation, and inertial cavitation. We found that inertial cavitation generated the highest rate of membrane poration. By establishing direct correlation of ultrasound-induced bubble activities with intracellular uptake and pore size, we designed a ramped pulse exposure scheme for optimizing microbubble excitation to improve sonoporation gene transfection. We implemented a novel sonoporation gene transfection system using an aqueous two phase system (ATPS) for efficient use of reagents and high throughput operation. Using plasmids coding for the green fluorescence protein (GFP), we achieved a sonoporation transfection efficiency in rate aortic smooth muscle cells (RASMCs) of 6.9%±2.2% (n=9), comparable with lipofection (7.5%±0.8%, n=9). Our results reveal characteristic microbubble behaviors responsible for sonoporation and demonstrated a rational strategy to improve sonoporation gene transfection. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. Reversible and irreversible vascular bioeffects induced by ultrasound and microbubbles in chorioallantoic membrane model

    Science.gov (United States)

    Tarapacki, Christine; Kuebler, Wolfgang M.; Tabuchi, Arata; Karshafian, Raffi

    2017-03-01

    Background: The application of ultrasound and microbubbles at therapeutic conditions has been shown to improve delivery of molecules, cause vasoconstriction, modulate blood flow and induce a vascular shut down in in vivo cancerous tissues. The underlying mechanism has been associated with the interaction of ultrasonically-induced microbubble oscillation and cavitation with the blood vessel wall. In this study, the effect of ultrasound and microbubbles on blood flow and vascular architecture was studied using a fertilized chicken egg CAM (chorioallantoic membrane) model. Methods: CAM at day 12 of incubation (Hamburger-Hamilton stage 38-40) were exposed to ultrasound at varying acoustic pressures (160, 240 and 320 kPa peak negative pressure) in the presence of Definity microbubbles and 70 kDa FITC dextran fluorescent molecules. A volume of 50 µL Definity microbubbles were injected into a large anterior vein of the CAM prior to ultrasound exposure. The ultrasound treatment sequence consisted of 5 s exposure at 500 kHz frequency, 8 cycles and 1 kHz pulse repetition frequency with 5 s off for a total exposure of 2 minutes. Fluorescent videos and images of the CAM vasculature were acquired using intravital microscopy prior, during and following the ultrasound exposure. Perfusion was quantified by measuring the length of capillaries in a region of interest using Adobe Illustrator. Results and Discussion: The vascular bioeffects induced by USMB increased with acoustic peak negative pressure. At 160 kPa, no visible differences were observed compared to the control. At 240 kPa, a transient decrease in perfusion with subsequent recovery within 15 minutes was observed, whereas at 320 kPa, the fluorescent images showed an irreversible vascular damage. The study indicates that a potential mechanism for the transient decrease in perfusion may be related to blood coagulation. The results suggest that ultrasound and microbubbles can induce reversible and irreversible vascular

  6. Ultrasonically induced dynamics of a contrast agent microbubble between two parallel elastic walls

    International Nuclear Information System (INIS)

    Doinikov, Alexander A; Bouakaz, Ayache

    2013-01-01

    This work presents the derivation of a Rayleigh–Plesset-like equation that describes the radial oscillation of a contrast agent microbubble between two elastic walls, assuming that the bubble is attached to one of them. The obtained equation is then used in numerical simulations in order to establish how the presence of the second wall affects the resonance properties and the scattered echo of the contrast microbubble. The effect of encapsulation on the dynamics of the microbubble is simulated by the Marmottant shell model which is commonly used for the modeling of the dynamics of lipid-shelled contrast agents. Two cases are examined. In the first, the mechanical properties of the walls are set to correspond to OptiCell chambers which are widely used in experiments on microbubble contrast agents. In the second, the properties of the walls correspond to walls of blood vessels. It is shown that the presence of the second wall increases the resonance frequency of the contrast microbubble and decreases the amplitudes of the radial oscillation and the scattered echo of the microbubble as compared to the case that the second wall is absent. It is also shown that the presence of the second wall can change noticeably the intensity of the second harmonic in the spectrum of the scattered pressure. It is demonstrated that, depending on the value of the driving frequency, the presence of the second wall can either increase or decrease the intensity of the second harmonic as compared to its intensity in the case that the second wall is absent. (paper)

  7. Detection of an occult hepatocellular carcinoma using ultrasound with liver-specific microbubbles

    International Nuclear Information System (INIS)

    Harvey, Christopher J.; Lim, Adrian K.P.; Blomley, Martin J.K.; Cosgrove, David O.; Taylor-Robinson, Simon D.; Gedroyc, Wladyslaw M.W.

    2002-01-01

    The radiological surveillance of cirrhosis to detect the development of hepatocellular carcinoma (HCC) is problematic because no highly sensitive and specific imaging investigation is available. Ultrasound is typically the first modality used but is less accurate than other imaging modalities. We report the first case of a patient with cirrhosis in whom US imaging with liver-specific microbubbles detected an HCC prior to its detection by MR. The use of liver-specific microbubble US contrast agents is an exciting development in the detection of HCC in chronic liver disease and may help to rectify some of the shortcomings of US. (orig.)

  8. Study of interactions between cells and microbubbles in high speed centrifugation field for biomolecule delivery.

    Science.gov (United States)

    He, Chuan; Chen, Jie

    2014-01-01

    Biomolecule delivery has a very wide range of applications in biology and medicine. In this study, a microbubble based delivery method was developed. In a high centrifugation field, cells deform and collide with microbubbles to induce intracellular pathways on cell membranes. As a result, biomaterials can then easily enter cells. Experimental results show that this delivery method can achieve high delivery efficiency. Simulation results showed that cells with more deformed structure experienced higher strain on cell membranes than cells with less deformed structure. The models can help explain how centrifugation affects cell membrane permeability. By controlling cell morphology and its mechanical properties, high biomolecule delivery efficiency can be achieved.

  9. Characteristics of phenomenon and sound in microbubble emission boiling

    International Nuclear Information System (INIS)

    Zhu Guangyu; Sun Licheng; Tang Jiguo

    2014-01-01

    Background: Nowadays, the efficient heat transfer technology is required in nuclear energy. Therefore, micro-bubble emission boiling (MEB) is getting more attentions from many researchers due to its extremely high heat-transfer dissipation capability. Purpose: An experimental setup was built up to study the correspondences between the characteristics on the amplitude spectrum of boiling sound in different boiling modes. Methods: The heat element was a copper block heated by four Si-C heaters. The upper of the copper block was a cylinder with the diameter of 10 mm and height of 10 mm. Temperature data were measured by three T-type sheathed thermocouples fitted on the upper of the copper block and recorded by NI acquisition system. The temperature of the heating surface was estimated by extrapolating the temperature distribution. Boiling sound data were acquired by hydrophone and processed by Fourier transform. Bubble behaviors were captured by high-speed video camera with light system. Results: In nucleate boiling region, the boiling was not intensive and as a result, the spectra didn't present any peak. While the MEB fully developed on the heating surface, an obvious peak came into being around the frequency of 300 Hz. This could be explained by analyzing the video data. The periodic expansion and collapse into many extremely small bubbles of the vapor film lead to MEB presenting an obvious characteristic peak in its amplitude spectrum. Conclusion: The boiling mode can be distinguished by its amplitude spectrum. When the MEB fully developed, it presented a characteristic peak in its amplitude spectrum around the frequency between 300-400 Hz. This proved that boiling sound of MEB has a close relation with the behavior of vapor film. (authors)

  10. Destructive hydrogenation. [British patent

    Energy Technology Data Exchange (ETDEWEB)

    1929-07-15

    Liquid or readily liquefiable products are obtained from solid distillable carbonaceous materials such as coals, oil shales or other bituminous substances by subjecting the said initial materials to destructive hydrogenation under mild conditions so that the formation of benzine is substantially avoided, and then subjecting the treated material to extraction by solvents. By hydrogenating under mild conditions the heavy oils which prevent the asphaltic substances from being precipitated are preserved, and the separation of the liquid products from the solid residue is facilitated. Solid paraffins and high boiling point constituents suitable for the production of lubricating oils may be removed before or after the extraction process. The extraction is preferably carried out under pressure with solvents which do not precipitate asphaltic substances. Brown coal containing 11 per cent ash is passed at 450/sup 0/C, and 200 atmospheres pressure in counter current to hydrogen; 40 per cent of the coal is converted into liquid products which are condensed out of the hydrogen stream; the pasty residue, on extraction with benzene, yields 45 per cent of high molecular weight products suitable for the production of lubricating oil.

  11. Innovation in Non Destructive Testing

    NARCIS (Netherlands)

    Wassink, C.H.P.

    2012-01-01

    In many established companies the pace of innovation is low. The Non-Destructive Testing sector is an example of a sector where the pace of innovation is very slow. Non-Destructive Testing (NDT) refers to the set of non-invasive activities used to determine the condition of objects or installations

  12. PLGA Nanoparticles for Ultrasound-Mediated Gene Delivery to Solid Tumors

    Directory of Open Access Journals (Sweden)

    Marxa Figueiredo

    2012-01-01

    Full Text Available This paper focuses on novel approaches in the field of nanotechnology-based carriers utilizing ultrasound stimuli as a means to spatially target gene delivery in vivo, using nanoparticles made with either poly(lactic-co-glycolic acid (PLGA or other polymers. We specifically discuss the potential for gene delivery by particles that are echogenic (amenable to destruction by ultrasound composed either of polymers (PLGA, polystyrene or other contrast agent materials (Optison, SonoVue microbubbles. The use of ultrasound is an efficient tool to further enhance gene delivery by PLGA or other echogenic particles in vivo. Echogenic PLGA nanoparticles are an attractive strategy for ultrasound-mediated gene delivery since this polymer is currently approved by the US Food and Drug Administration for drug delivery and diagnostics in cancer, cardiovascular disease, and also other applications such as vaccines and tissue engineering. This paper will review recent successes and the potential of applying PLGA nanoparticles for gene delivery, which include (a echogenic PLGA used with ultrasound to enhance local gene delivery in tumors or muscle and (b PLGA nanoparticles currently under development, which could benefit in the future from ultrasound-enhanced tumor targeted gene delivery.

  13. Splenic abnormalities: a comparative review of ultrasound, microbubble-enhanced ultrasound and computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Peddu, P.; Shah, M.; Sidhu, P.S. E-mail: paul.sidhu@kingsch.nhs.uk

    2004-09-01

    The ultrasound appearances of abnormalities of the spleen are reviewed and images compared with computed tomography. Focal lesions, both benign and malignant, trauma, infarction and congenital abnormalities are presented. The use of microbubble ultrasound contrast media as an aid to identifying and characterizing abnormalities is discussed.

  14. Decontamination System Development of Radioative Activated Carbon using Micro-bubbles

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Jong seon; Kim, Wi soo [NESS, Daejeon (Korea, Republic of); Han, Byoung sub. [Enesys Co., Daejeon (Korea, Republic of)

    2016-10-15

    This study was aimed to develop a decontamination system by applying such technical characteristics that minimizes a generation of secondary wastes while decontaminating radiation wastes. The radioactive activated carbon is removed from the end-of-life air cleaning filter in replacement or decommission of nuclear power plant or nuclear facility. By removing radioactive activated carbon, the filter would be classified as a low radioactive contaminant. And thus the amount of radioactive wastes and the treatment cost would be decreased. We are in development of the activated carbon cleaning technique by utilizing micro-bubbles, which improve efficiency and minimize damage of activated carbon. The purpose of using micro-bubbles is to decontamination carbon micropore, which is difficult to access, by principle of cavitation phenomenon generated in collapse of micro-bubbles. In this study, we introduced the micro-bubble decontamination system developed to decontaminate activated carbon. For further researches, we will determine carbon weight change and the decontamination rate under the experimental conditions such as temperature and pH.

  15. Decontamination System Development of Radioative Activated Carbon using Micro-bubbles

    International Nuclear Information System (INIS)

    Jeon, Jong seon; Kim, Wi soo; Han, Byoung sub.

    2016-01-01

    This study was aimed to develop a decontamination system by applying such technical characteristics that minimizes a generation of secondary wastes while decontaminating radiation wastes. The radioactive activated carbon is removed from the end-of-life air cleaning filter in replacement or decommission of nuclear power plant or nuclear facility. By removing radioactive activated carbon, the filter would be classified as a low radioactive contaminant. And thus the amount of radioactive wastes and the treatment cost would be decreased. We are in development of the activated carbon cleaning technique by utilizing micro-bubbles, which improve efficiency and minimize damage of activated carbon. The purpose of using micro-bubbles is to decontamination carbon micropore, which is difficult to access, by principle of cavitation phenomenon generated in collapse of micro-bubbles. In this study, we introduced the micro-bubble decontamination system developed to decontaminate activated carbon. For further researches, we will determine carbon weight change and the decontamination rate under the experimental conditions such as temperature and pH

  16. Microbubble signal and trial of org in acute stroke treatment (TOAST) classification in ischemic stroke.

    Science.gov (United States)

    Lee, Chan-Hyuk; Kang, Hyun Goo; Lee, Ji Sung; Ryu, Han Uk; Jeong, Seul-Ki

    2018-07-15

    Right-to-left shunt (RLS) through a patent foramen ovale (PFO) is likely associated with ischemic stroke. Many studies have attempted to demonstrate the association between RLS and ischemic stroke. However, information on the association between the degree of RLS and the subtypes of ischemic stroke categorized by the Trial of ORG 10172 in Acute Stroke Treatment (TOAST) classification is lacking. This was a retrospective study involving 508 patients with ischemic stroke who underwent a transcranial Doppler (TCD) microbubble test between 2013 and 2015. The degree of RLS was divided into 4 grades according to the microbubble signal (MBS) as follows: no MBS, grade 1; MBS  20, grade 3; curtain sign, grade 4. The degree of RLS and the type of ischemic stroke as classified by TOAST were analyzed and compared with other clinical information and laboratory findings. The higher RLS grade was associated with the cardioembolism (CE) and stroke of undetermined etiology (SUE), and the microbubble signals were inversely related with small vessel disease (SVD). An MBS higher than grade 3 showed a 2.95-fold higher association with SUE than large artery atherosclerosis (LAA), while grade 4 MBS revealed an approximately 8-fold higher association with SUE than LAA. RLS identified by the TCD microbubble test was significantly and independently associated with cryptogenic ischemic stroke (negative evaluation). Subsequent studies are needed to determine the biologic relationship between RLS and ischemic stroke, particularly the cryptogenic subtype of ischemic stroke. Copyright © 2018 Elsevier B.V. All rights reserved.

  17. Magnetic stents retain nanoparticle-bound antirestenotic drugs transported by lipid microbubbles.

    Science.gov (United States)

    Räthel, T; Mannell, H; Pircher, J; Gleich, B; Pohl, U; Krötz, F

    2012-05-01

    Coating coronary stents with antirestenotic drugs revolutionized interventional cardiology. We developed a system for post-hoc drug delivery to uncoated stents. We coupled rapamycin or a chemically similar fluorescent dye to superparamagnetic nanoparticles. The antiproliferative activity of rapamycin coupled to nanoparticles was confirmed in vitro in primary porcine vascular cells. The particles were then incorporated into lipid based microbubbles. Commercially available stents were made magnetizable by nickel plating and used to induce strong field gradients in order to capture magnetic microbubbles from flowing liquids when placed in an external magnetic field. Nanoparticle bound Rapamycin dose dependently inhibited cell proliferation in vitro. Magnetic microcbubbles carrying coated nanoparticles were caught by magnets placed external to a flow-through tube. Plating commercial stents with nickel resulted in increased deposition at stent struts and allowed for widely increased distance of external magnets. Deposition depended on circulation time and velocity and distance of magnets. Deposited microbubbles were destroyed by ultrasound and delivered their cargo to targeted sites. Drugs can be incorporated into nanoparticle loaded microbubbles and thus be delivered to magnetizable stents from circulating fluids by applying external magnetic fields. This technology could allow for post-hoc drug coating of already implanted vascular stents.

  18. Wavelet Spatial Energy Spectrums Studies on Drag Reduction by Micro-bubble Injection

    International Nuclear Information System (INIS)

    Ling Zhen; Yassin Hassan

    2006-01-01

    In this study, continuous wavelet transforms and spatial correlation techniques are employed to determine the space-localized wavenumber energy spectrum of the velocity signals in turbulent channel flow. The flow conditions correspond to single phase flow and micro-bubbles injected two phase flow. The wavelet energy spectrums demonstrate that the wavenumber (eddy size) content of the velocity signals is not only space-dependent but also micro-bubbles can impact the eddy size content. Visual observations of the wavelet energy spectrum spatial distribution was realized by using Particle Image Velocimetry (PIV) measurement technique. The two phase flow condition corresponds to a drag reduction of 38.4% with void fraction of 4.9%. The present results provide evidence that micro-bubbles in the boundary layer of a turbulent channel flow can help adjust the eddy size distributions near the wall. This can assist in explaining that micro-bubbles are performing as buffers to keep the energy of fluid particles going in stream-wise direction and reducing the energy of fluid particles going in normal direction. (authors)

  19. Microbubble-induced detachment of coadhering oral bacteria from salivary pellicles

    NARCIS (Netherlands)

    Sharma, PK; Gibcus, MJ; van der Mei, HC; Busscher, HJ

    The presence and maturity of the salivary pellicle influences microbial adhesion and its tenacity in the oral cavity, posing a challenge to different plaque-control systems. Some plaque-control systems rely on surface-tension forces arising from passing microbubbles sprayed over the pellicle.

  20. Sterilization of microorganisms by the supercritical carbon dioxide micro-bubble method.

    Science.gov (United States)

    Ishikawa, H; Shimoda, M; Shiratsuchi, H; Osajima, Y

    1995-10-01

    Lactobacillus brevis and Saccharomyces cerevisiae were completely sterilized by the supercritical (SC) CO2 micro-bubble method. Gaseous (G) and liquid (LQ) CO2 were used in a similar manner to compare the sterilizing effect. Among the three treatments, the microorganisms were only effectively sterilized by the SC CO2 treatment at 25 MPa and 35 degrees C.

  1. Wavelength-dependent Faraday–Tyndall effect on laser-induced microbubble in gold colloid

    International Nuclear Information System (INIS)

    Liaw, Jiunn-Woei; Tsai, Shiao-Wen; Lin, Hung-Hsun; Yen, Tzu-Chen; Chen, Bae-Renn

    2012-01-01

    The cavitation microbubbles in dilute gold colloids of different concentrations (2–10 ppm) induced by a focused nanosecond-pulsed laser beam were measured and characterized at different wavelengths by using the passive and active ultrasound measurements. Three colloids with gold nanoparticles (GNPs) of different sizes (10, 45, and 75 nm) were used for experiment. The results show that the lifespan of the microbubble is reduced as the concentration of GNP increases, particularly at the wavelength of 532 nm, the surface plasmon resonance (SPR) of GNP. In contrast, at the off-resonant wavelength (e.g. 700 nm), the lifespan reduction is relatively small. This wavelength-dependent cavitation is attributed to the Faraday–Tyndall effect, a strong light scattering by GNPs. A slight defocusing of the Gaussian beam in gold colloid was proposed. Hence, the waist of the focused beam increases to reduce the optical breakdown in gold colloid. For simplicity, a linear relation between the incremental waist radius of Gaussian beam and the concentration of GNP was assumed. According to this formulation, the theoretical results are consistent with the experimental ones. In addition, the dynamics of the microbubble in gold colloid measured by the active ultrasound method agree with the Rayleigh–Plesset model. -- Highlights: ► The Faraday–Tyndall effect of gold colloid on laser induced microbubble is studied. ► Faraday–Tyndall effect of gold colloid causes the defocusing of laser beam. ► Lifespan of the microbubble is reduced as the concentration of GNP increases. ► Light scattering of laser beam at the surface plasmon resonance of GNP is the maximum.

  2. Non-destructive inservice inspections

    International Nuclear Information System (INIS)

    Kauppinen, P.; Sarkimo, M.; Lahdenperae, K.

    1998-01-01

    In order to assess the possible damages occurring in the components and structures of operating nuclear power plants during service the main components and structures are periodically inspected by non-destructive testing techniques. The reliability of non-destructive testing techniques applied in these inservice inspections is of major importance because the decisions concerning the needs for repair of components are mainly based on the results of inspections. One of the targets of this research program has been to improve the reliability of non-destructive testing. This has been addressed in the sub-projects which are briefly summarised here. (author)

  3. Methylene blue microbubbles as a model dual-modality contrast agent for ultrasound and activatable photoacoustic imaging

    Science.gov (United States)

    Jeon, Mansik; Song, Wentao; Huynh, Elizabeth; Kim, Jungho; Kim, Jeesu; Helfield, Brandon L.; Leung, Ben Y. C.; Goertz, David E.; Zheng, Gang; Oh, Jungtaek; Lovell, Jonathan F.; Kim, Chulhong

    2014-01-01

    Ultrasound and photoacoustic imaging are highly complementary modalities since both use ultrasonic detection for operation. Increasingly, photoacoustic and ultrasound have been integrated in terms of hardware instrumentation. To generate a broadly accessible dual-modality contrast agent, we generated microbubbles (a standard ultrasound contrast agent) in a solution of methylene blue (a standard photoacoustic dye). This MB2 solution was formed effectively and was optimized as a dual-modality contrast solution. As microbubble concentration increased (with methylene blue concentration constant), photoacoustic signal was attenuated in the MB2 solution. When methylene blue concentration increased (with microbubble concentration held constant), no ultrasonic interference was observed. Using an MB2 solution that strongly attenuated all photoacoustic signal, high powered ultrasound could be used to burst the microbubbles and dramatically enhance photoacoustic contrast (>800-fold increase), providing a new method for spatiotemporal control of photoacoustic signal generation.

  4. Targeted microbubbles for imaging tumor angiogenesis: assessment of whole-body biodistribution with dynamic micro-PET in mice

    DEFF Research Database (Denmark)

    Willmann, Jürgen K; Cheng, Zhen; Davis, Corrine

    2008-01-01

    To evaluate in vivo whole-body biodistribution of microbubbles (MBs) targeted to tumor angiogenesis-related vascular endothelial growth factor (VEGF) receptor 2 (VEGFR2) by using dynamic micro-positron emission tomography (PET) in living mice.......To evaluate in vivo whole-body biodistribution of microbubbles (MBs) targeted to tumor angiogenesis-related vascular endothelial growth factor (VEGF) receptor 2 (VEGFR2) by using dynamic micro-positron emission tomography (PET) in living mice....

  5. Osteoclast inhibition impairs chondrosarcoma growth and bone destruction.

    Science.gov (United States)

    Otero, Jesse E; Stevens, Jeff W; Malandra, Allison E; Fredericks, Douglas C; Odgren, Paul R; Buckwalter, Joseph A; Morcuende, Jose

    2014-12-01

    Because Chondrosarcoma is resistant to available chemotherapy and radiation regimens, wide resection is the mainstay in treatment, which frequently results in high morbidity and which may not prevent local recurrence. There is a clear need for improved adjuvant treatment of this malignancy. We have observed the presence of osteoclasts in the microenvironment of chondrosarcoma in human pathological specimens. We utilized the Swarm rat chondrosarcoma (SRC) model to test the hypothesis that osteoclasts affect chondrosarcoma pathogenesis. We implanted SRC tumors in tibia of Sprague-Dawley rats and analyzed bone histologically and radiographically for bone destruction and tumor growth. At three weeks, tumors invaded local bone causing cortical disruption and trabecular resorption. Bone destruction was accompanied by increased osteoclast number and resorbed bone surface. Treatment of rats with the zoledronic acid prevented cortical destruction, inhibited trabecular resorption, and resulted in decreased tumor volume in bone. To confirm that inhibition of osteoclasts per se, and not off-target effects of drug, was responsible for the prevention of tumor growth and bone destruction, we implanted SRC into osteopetrotic rat tibia. SRC-induced bone destruction and tumor growth were impaired in osteopetrotic bone compared with control bone. The results from our animal model demonstrate that osteoclasts contribute to chondrosarcoma-mediated bone destruction and tumor growth and may represent a therapeutic target in particular chondrosarcoma patients. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  6. Enhancement of aerobic biodegradation in an oxygen-limiting environment using a saponin-based microbubble suspension

    International Nuclear Information System (INIS)

    Choi, Yong Ju; Kim, Young-Jin; Nam, Kyoungphile

    2009-01-01

    This study investigated the ability of a saponin-based microbubble suspension to enhance aerobic biodegradation of phenanthrene by subsurface delivery. As the microbubble suspension flowed through a sand column pressure buildup and release was repeatedly observed, which delivered oxygen to the less permeable regions. Burkholderia cepacia RPH1, a phenanthrene-degrading bacterium, was mainly transported in a suspended form in the microbubble suspension. When three pore volumes of the microbubble suspension containing B. cepacia RPH1 was introduced into a column contaminated with phenanthrene (100 mg/kg), the oxygen content declined to 5% from an initial value of 20% within 5 days and correspondingly, 34.4% of initial phenanthrene was removed in 8 days. The addition of two further three pore volumes enhanced the biodegradation efficiency by a factor of 2.2. Our data suggest that a saponin-based microbubble suspension could be a potential carrier for enhancing the aerobic biodegradation under an oxygen-limiting environment. - Microbubble suspension can enhance the phenanthrene biodegradation under an oxygen-limiting condition.

  7. Enhancement of aerobic biodegradation in an oxygen-limiting environment using a saponin-based microbubble suspension

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Yong Ju; Kim, Young-Jin [Department of Civil and Environmental Engineering, Seoul National University, Shillim-dong, Gwanak-gu, Seoul (Korea, Republic of); Nam, Kyoungphile, E-mail: kpnam@snu.ac.k [Department of Civil and Environmental Engineering, Seoul National University, Shillim-dong, Gwanak-gu, Seoul (Korea, Republic of)

    2009-08-15

    This study investigated the ability of a saponin-based microbubble suspension to enhance aerobic biodegradation of phenanthrene by subsurface delivery. As the microbubble suspension flowed through a sand column pressure buildup and release was repeatedly observed, which delivered oxygen to the less permeable regions. Burkholderia cepacia RPH1, a phenanthrene-degrading bacterium, was mainly transported in a suspended form in the microbubble suspension. When three pore volumes of the microbubble suspension containing B. cepacia RPH1 was introduced into a column contaminated with phenanthrene (100 mg/kg), the oxygen content declined to 5% from an initial value of 20% within 5 days and correspondingly, 34.4% of initial phenanthrene was removed in 8 days. The addition of two further three pore volumes enhanced the biodegradation efficiency by a factor of 2.2. Our data suggest that a saponin-based microbubble suspension could be a potential carrier for enhancing the aerobic biodegradation under an oxygen-limiting environment. - Microbubble suspension can enhance the phenanthrene biodegradation under an oxygen-limiting condition.

  8. [Molecular imaging of thrombus with microbubbles targeted to alphavbeta3-integrin using an agarose flow chamber model].

    Science.gov (United States)

    Hu, Guang-quan; Liu, Jian; Yang, Li; Yan, Yi; Wu, Jue-fei; Xie, Jia-jia; Cai, Jing-jing; Ji, Li-jing; Bin, Jian-ping

    2010-03-01

    To assess the binding ability of microbubbles targeted to alphavbeta3-integrin (MBp) for thrombus-targeted contrast-enhanced ultrasound. Targeted microbubbles were prepared by conjugating the monoclonal antibody against alphavbeta3-integrin to lipid shell of the microbubble via the avidin-biotin bridges. Equivalent isotype control microbubbles (MB) or targeted ultrasound microbubbles (MBp) were randomly added into the flow chamber. After a 30-min incubation with the thrombus fixed in an agarose flow chamber model, the thrombus was washed with a continuous flow of PBS solution (15 cm/s) for 2, 4, 6, 8 and 10 min, followed by thrombus imaging using contrast-enhanced ultrasound and measurement of the video intensity (VI) values of the images. The VI of the thrombus in MBp group was reduced by 28%-66%, while that in control MB group was decreased by 87%-94%, and the VI values of the thrombus group were significantly greater in former group at each of the time points (Pevaluation of the thrombus-binding capability of the targeted microbubble (MBp) by simulating the shear stress in vivo can be helpful for predicting the in vivo effects of ultrasonic molecular imaging using MBp.

  9. Mechanical and dynamic characteristics of encapsulated microbubbles coupled by magnetic nanoparticles as multifunctional imaging and drug delivery agents

    Science.gov (United States)

    Guo, Gepu; Lu, Lu; Yin, Leilei; Tu, Juan; Guo, Xiasheng; Wu, Junru; Xu, Di; Zhang, Dong

    2014-11-01

    Development of magnetic encapsulated microbubble agents that can integrate multiple diagnostic and therapeutic functions is a key focus in both biomedical engineering and nanotechnology and one which will have far-reaching impact on medical diagnosis and therapies. However, properly designing multifunctional agents that can satisfy particular diagnostic/therapeutic requirements has been recognized as rather challenging, because there is a lack of comprehensive understanding of how the integration of magnetic nanoparticles to microbubble encapsulating shells affects their mechanical properties and dynamic performance in ultrasound imaging and drug delivery. Here, a multifunctional imaging contrast and in-situ gene/drug delivery agent was synthesized by coupling super paramagnetic iron oxide nanoparticles (SPIOs) into albumin-shelled microbubbles. Systematical studies were performed to investigate the SPIO-concentration-dependence of microbubble mechanical properties, acoustic scattering response, inertial cavitation activity and ultrasound-facilitated gene transfection effect. These demonstrated that, with the increasing SPIO concentration, the microbubble mean diameter and shell stiffness increased and ultrasound scattering response and inertial cavitation activity could be significantly enhanced. However, an optimized ultrasound-facilitated vascular endothelial growth factor transfection outcome would be achieved by adopting magnetic albumin-shelled microbubbles with an appropriate SPIO concentration of 114.7 µg ml-1. The current results would provide helpful guidance for future development of multifunctional agents and further optimization of their diagnostic/therapeutic performance in clinic.

  10. Mechanical and dynamic characteristics of encapsulated microbubbles coupled by magnetic nanoparticles as multifunctional imaging and drug delivery agents

    International Nuclear Information System (INIS)

    Guo, Gepu; Lu, Lu; Tu, Juan; Guo, Xiasheng; Zhang, Dong; Yin, Leilei; Wu, Junru; Xu, Di

    2014-01-01

    Development of magnetic encapsulated microbubble agents that can integrate multiple diagnostic and therapeutic functions is a key focus in both biomedical engineering and nanotechnology and one which will have far-reaching impact on medical diagnosis and therapies. However, properly designing multifunctional agents that can satisfy particular diagnostic/therapeutic requirements has been recognized as rather challenging, because there is a lack of comprehensive understanding of how the integration of magnetic nanoparticles to microbubble encapsulating shells affects their mechanical properties and dynamic performance in ultrasound imaging and drug delivery. Here, a multifunctional imaging contrast and in-situ gene/drug delivery agent was synthesized by coupling super paramagnetic iron oxide nanoparticles (SPIOs) into albumin-shelled microbubbles. Systematical studies were performed to investigate the SPIO-concentration-dependence of microbubble mechanical properties, acoustic scattering response, inertial cavitation activity and ultrasound-facilitated gene transfection effect. These demonstrated that, with the increasing SPIO concentration, the microbubble mean diameter and shell stiffness increased and ultrasound scattering response and inertial cavitation activity could be significantly enhanced. However, an optimized ultrasound-facilitated vascular endothelial growth factor transfection outcome would be achieved by adopting magnetic albumin-shelled microbubbles with an appropriate SPIO concentration of 114.7 µg ml −1 . The current results would provide helpful guidance for future development of multifunctional agents and further optimization of their diagnostic/therapeutic performance in clinic. (paper)

  11. Lipid microbubbles as a vehicle for targeted drug delivery using focused ultrasound-induced blood-brain barrier opening.

    Science.gov (United States)

    Sierra, Carlos; Acosta, Camilo; Chen, Cherry; Wu, Shih-Ying; Karakatsani, Maria E; Bernal, Manuel; Konofagou, Elisa E

    2017-04-01

    Focused ultrasound in conjunction with lipid microbubbles has fully demonstrated its ability to induce non-invasive, transient, and reversible blood-brain barrier opening. This study was aimed at testing the feasibility of our lipid-coated microbubbles as a vector for targeted drug delivery in the treatment of central nervous system diseases. These microbubbles were labeled with the fluorophore 5-dodecanoylaminfluorescein. Focused ultrasound targeted mouse brains in vivo in the presence of these microbubbles for trans-blood-brain barrier delivery of 5-dodecanoylaminfluorescein. This new approach, compared to previously studies of our group, where fluorescently labeled dextrans and microbubbles were co-administered, represents an appreciable improvement in safety outcome and targeted drug delivery. This novel technique allows the delivery of 5-dodecanoylaminfluorescein at the region of interest unlike the alternative of systemic exposure. 5-dodecanoylaminfluorescein delivery was assessed by ex vivo fluorescence imaging and by in vivo transcranial passive cavitation detection. Stable and inertial cavitation doses were quantified. The cavitation dose thresholds for estimating, a priori, successful targeted drug delivery were, for the first time, identified with inertial cavitation were concluded to be necessary for successful delivery. The findings presented herein indicate the feasibility and safety of the proposed microbubble-based targeted drug delivery and that, if successful, can be predicted by cavitation detection in vivo.

  12. Lipid microbubbles as a vehicle for targeted drug delivery using focused ultrasound-induced blood–brain barrier opening

    Science.gov (United States)

    Sierra, Carlos; Acosta, Camilo; Chen, Cherry; Wu, Shih-Ying; Karakatsani, Maria E; Bernal, Manuel

    2016-01-01

    Focused ultrasound in conjunction with lipid microbubbles has fully demonstrated its ability to induce non-invasive, transient, and reversible blood–brain barrier opening. This study was aimed at testing the feasibility of our lipid-coated microbubbles as a vector for targeted drug delivery in the treatment of central nervous system diseases. These microbubbles were labeled with the fluorophore 5-dodecanoylaminfluorescein. Focused ultrasound targeted mouse brains in vivo in the presence of these microbubbles for trans-blood–brain barrier delivery of 5-dodecanoylaminfluorescein. This new approach, compared to previously studies of our group, where fluorescently labeled dextrans and microbubbles were co-administered, represents an appreciable improvement in safety outcome and targeted drug delivery. This novel technique allows the delivery of 5-dodecanoylaminfluorescein at the region of interest unlike the alternative of systemic exposure. 5-dodecanoylaminfluorescein delivery was assessed by ex vivo fluorescence imaging and by in vivo transcranial passive cavitation detection. Stable and inertial cavitation doses were quantified. The cavitation dose thresholds for estimating, a priori, successful targeted drug delivery were, for the first time, identified with inertial cavitation were concluded to be necessary for successful delivery. The findings presented herein indicate the feasibility and safety of the proposed microbubble-based targeted drug delivery and that, if successful, can be predicted by cavitation detection in vivo. PMID:27278929

  13. Influencing factors on microbubble ozonation treatment of acid red 3R wastewater

    Directory of Open Access Journals (Sweden)

    Yurong YA

    2017-08-01

    Full Text Available The microbubble ozonation was used to treat acid red 3R wastewater in order to investigate the influencing factors on its performance. The effects of ozone dose, initial acid red 3R concentration and activated carbon on the performance of microbubble ozonation treatment of acid red 3R wastewater are investigated. The decolorization rate, TOC removal rate, pH variation and ozone utilization efficiency in the microbubble ozonation treatment are compared under different treatment conditions. The results indicate that when increasing ozone dose or decreasing initial acid red 3R concentration, both decolorization rate and TOC removal rate of acid red 3R wastewater increase, but ozone utilization efficiency decreases. The coal-based activated carbon shows strong catalytic activity for microbubble ozonation, which could enhance the decolorization rate and TOC removal rate of acid red 3R wastewater. The better performance of microbubble ozonation treatment is achieved when the ozone dose is 48.3 mg/min and the initial acid red 3R mass concentration is 100 mg/L. Under these conditions, the decolorization efficiency reaches to 100% after treatment for 30 min, the TOC removal efficiency reaches to 78.0% after treatment for 120 min, the reaction rate constant of TOC removal is 0.015 min-1 and the ozone utilization efficiency is higher than 99%. With addition of the coal-based activated carbon of 5 g/L, the decolorization efficiency reaches to 100% after treatment for 15 min, the TOC removal efficiency reaches to 91.2% after treatment for 120 min and the reaction rate constant of TOC removal increases to 0037 min-1.The accumulation and following degradation of intermediate products of small molecule organic acid happens during treatment process, and as a result, the solution pH decreases initially and then increases. Therefore, the optimization of influencing factors for microbubble ozonation could increase both contaminant removal

  14. Verification of Chemical Weapons Destruction

    International Nuclear Information System (INIS)

    Lodding, J.

    2010-01-01

    The Chemical Weapons Convention is the only multilateral treaty that bans completely an entire category of weapons of mass destruction under international verification arrangements. Possessor States, i.e. those that have chemical weapons stockpiles at the time of becoming party to the CWC, commit to destroying these. All States undertake never to acquire chemical weapons and not to help other States acquire such weapons. The CWC foresees time-bound chemical disarmament. The deadlines for destruction for early entrants to the CWC are provided in the treaty. For late entrants, the Conference of States Parties intervenes to set destruction deadlines. One of the unique features of the CWC is thus the regime for verifying destruction of chemical weapons. But how can you design a system for verification at military sites, while protecting military restricted information? What degree of assurance is considered sufficient in such circumstances? How do you divide the verification costs? How do you deal with production capability and initial declarations of existing stockpiles? The founders of the CWC had to address these and other challenges in designing the treaty. Further refinement of the verification system has followed since the treaty opened for signature in 1993 and since inspection work was initiated following entry-into-force of the treaty in 1997. Most of this work concerns destruction at the two large possessor States, Russia and the United States. Perhaps some of the lessons learned from the OPCW experience may be instructive in a future verification regime for nuclear weapons. (author)

  15. Fabrication and imaging study of ultrasound/fluorescence bi-modal contrast agent based on polymeric microbubbles

    International Nuclear Information System (INIS)

    Xing Zhanwen; Ke Hengte; Wang Jinrui; Zhao Bo; Qu Enze; Yue Xiuli; Dai Zhifei

    2013-01-01

    Objective: To fabricate an ultrasound/fluorescence bi-modal contrast agent by encapsulating fluorescent quantum dots into polymeric ultrasound contrast agent microbubbles. Methods: Polylactic acid (PLA, 500 mg), (1R)-(+)-camphor (50 mg) and CdSe/ZnS quantum dots (0.5 ml, 2.3 μmol/L)were dissolved or dispersed in dichloromethane (10 ml) to form in an organic phase. Ammonium carbonate solution and poly (vinyl alcohol) solution were employed as the internal and external water phase, respectively. The fluorescent microbubbles were generated using double emulsion solvent evaporation and lyophilization methods. The morphology and illumination were characterized by scanning electron microscopy (SEM) and fluorescence spectrophotometry. Synchronized contrast-enhanced ultrasound and fluorescence imaging was acquired by injecting fluorescent microbubbles into the silicone tube coupled to a self-made ultrasound/fluorescence imaging device. Ultrasound/fluorescence bi-modal in vivo imaging was acquired on the kidney of New Zealand rabbits and suckling mice. Results: The fluorescent microbubbles were hollow spheres with an averaged diameter of (1.62 ± 1.47) μm. More than 99% of these microbubbles were less than 8 μm in diameter, which met the size criteria for ultrasound contrast agents. The fluorescence emission peak of the microbubbles appeared at 632 nm, indicating that good luminescence properties of quantum dots were maintained. In vitro ultrasound/fluorescence imaging showed no echoic signal when the silicone tube was filled with saline, but there was a strong echo when filled with fluorescent microbubbles. The liquid column with fluorescent microbubbles emitted red luminescence under ultraviolet irradiation. The kidney of the rabbit was remarkably enhanced after the administration of fluorescent microbubbles. Bright fluorescence could be observed at the injection site of the suckling mice via subcutaneous injection. Conclusions: A bi-modal but single contrast agent

  16. Cross correlation coefficients of turbulent boundary layer with micro-bubble injection

    International Nuclear Information System (INIS)

    Claudia del Carmen Gutierrez-Torres; Yassin A Hassan; Jose Alfredo Jimenez-Bernal

    2005-01-01

    Full text of publication follows: Injection of micro-bubbles within the turbulent boundary layer has been investigated for a several years as a method to achieve drag reduction. However, the physical mechanism of this phenomenon is not fully understood yet. Experiments in a channel flow for single phase (water) and two phase (water and micro-bubbles) flows under different void fraction conditions are reported for a Reynolds number of 5128. Particle Image Velocimetry technique is used to measure instantaneous velocity fields. Consequently the cross-correlation coefficient Ruv can be calculated along the stream-wise direction for various different y + positions and along the normal direction for the fluctuating components of the velocity obtained from the instantaneous velocity fields. The experiments were carried out in a rectangular acrylic channel, whose dimensions are 4.8 m length, 20.6 cm wide and 5.6 cm height. Water was driven trough the channel by gravity from a tank, which was located 3 m above the channel. Then, water was conducted to a lower tank; from which water was pumped to the upper thank forming a closed loop. Upper tank's water level was kept constant through the tests to ensure constant flow rate trough the channel. The velocity field in the x-y plane was obtained by particle image velocimetry (PIV) at 3.15 m downstream from the channel inlet. A Nd:YAG laser with a wavelength of 532 nm (green light) and power of 350 mJ per pulse is utilized. The particles used for seeding have a diameter that goes from 6-9 μm with a specific gravity almost identical to water s specific gravity. The laser light scattered from the seeding particles was recorded using a CCD Kodak Megaplus camera, Model ES 1.0, 1008 x 1018 pixels. The viewing area was 1.28 cm 2 and was located close to the channel wall. The system recorded 30 velocity fields per second. Each velocity field was obtained from a pair of consecutive images capturing the second image of the pair 1 ms after

  17. Microbubble embedded with upconversion nanoparticles as a bimodal contrast agent for fluorescence and ultrasound imaging

    International Nuclear Information System (INIS)

    Jin, Birui; Lin, Min; You, Minli; Xu, Feng; Lu, Tianjian; Zong, Yujin; Wan, Mingxi; Duan, Zhenfeng

    2015-01-01

    Bimodal imaging offers additional imaging signal thus finds wide spread application in clinical diagnostic imaging. Fluorescence/ultrasound bimodal imaging contrast agent using fluorescent dyes or quantum dots for fluorescence signal has emerged as a promising method, which however requires visible light or UV irradiation resulting in photobleaching, photoblinking, auto-fluorescence and limited tissue penetration depth. To surmount these problems, we developed a novel bimodal contrast agent using layer-by-layer assembly of upconversion nanoparticles onto the surface of microbubbles. The resulting microbubbles with average size of 2 μm provide enhanced ultrasound echo for ultrasound imaging and upconversion emission upon near infrared irradiation for fluorescence imaging. The developed bimodal contrast agent holds great potential to be applied in ultrasound target technique for targeted diseases diagnostics and therapy. (paper)

  18. Cross correlation coefficients of turbulent boundary layer with micro-bubble injection

    Energy Technology Data Exchange (ETDEWEB)

    Claudia del Carmen Gutierrez-Torres [LABINTHAP-SEPI-ESIME, Instituto Politecnico Nacional, U.P. Adolfo Lopez Mateos Edif. 5 3er. Piso, Col Lindavista, C.P. 07738, Mexico, D. F. (Mexico); Yassin A Hassan; Jose Alfredo Jimenez-Bernal [Texas A and M University, College Station, Tx. 77843-3133 (United States)

    2005-07-01

    Full text of publication follows: Injection of micro-bubbles within the turbulent boundary layer has been investigated for a several years as a method to achieve drag reduction. However, the physical mechanism of this phenomenon is not fully understood yet. Experiments in a channel flow for single phase (water) and two phase (water and micro-bubbles) flows under different void fraction conditions are reported for a Reynolds number of 5128. Particle Image Velocimetry technique is used to measure instantaneous velocity fields. Consequently the cross-correlation coefficient Ruv can be calculated along the stream-wise direction for various different y{sup +} positions and along the normal direction for the fluctuating components of the velocity obtained from the instantaneous velocity fields. The experiments were carried out in a rectangular acrylic channel, whose dimensions are 4.8 m length, 20.6 cm wide and 5.6 cm height. Water was driven trough the channel by gravity from a tank, which was located 3 m above the channel. Then, water was conducted to a lower tank; from which water was pumped to the upper thank forming a closed loop. Upper tank's water level was kept constant through the tests to ensure constant flow rate trough the channel. The velocity field in the x-y plane was obtained by particle image velocimetry (PIV) at 3.15 m downstream from the channel inlet. A Nd:YAG laser with a wavelength of 532 nm (green light) and power of 350 mJ per pulse is utilized. The particles used for seeding have a diameter that goes from 6-9 {mu}m with a specific gravity almost identical to water s specific gravity. The laser light scattered from the seeding particles was recorded using a CCD Kodak Megaplus camera, Model ES 1.0, 1008 x 1018 pixels. The viewing area was 1.28 cm{sup 2} and was located close to the channel wall. The system recorded 30 velocity fields per second. Each velocity field was obtained from a pair of consecutive images capturing the second image of

  19. DESTRUCTIVE EDUCATIONAL PRACTICES AT UNIVERSITY

    Directory of Open Access Journals (Sweden)

    Андрей Владимирович Феоктистов

    2013-05-01

    Full Text Available The article is devoted to problems of origin and development of destructive educational practices at university. The authors focus on complex of interactions that disturb the existing in the academic environment norms and ethical principles. The most vivid evidence of destructive educational practice is the corruption issue. On the basis of the analyzed publications dealing with dynamics of corruption in the Russian higher education and the results of the survey by questionnaire, carried out at the technical university, the complex of recommendations has been prepared and suggested that is directed at minimization of destructive behavior at university.DOI: http://dx.doi.org/10.12731/2218-7405-2013-4-28

  20. Facilitation of Drug Transport across the Blood–Brain Barrier with Ultrasound and Microbubbles

    OpenAIRE

    Meairs, Stephen

    2015-01-01

    Medical treatment options for central nervous system (CNS) diseases are limited due to the inability of most therapeutic agents to penetrate the blood–brain barrier (BBB). Although a variety of approaches have been investigated to open the BBB for facilitation of drug delivery, none has achieved clinical applicability. Mounting evidence suggests that ultrasound in combination with microbubbles might be useful for delivery of drugs to the brain through transient opening of the BBB. This techni...

  1. Effect of low-frequency low-intensity ultrasound with microbubbles on prostate cancer hypoxia.

    Science.gov (United States)

    Hou, Rui; Xu, Yanjun; Lu, Qijie; Zhang, Yang; Hu, Bing

    2017-10-01

    Angiogenesis plays an important role in tumor growth, invasiveness, and metastasis. It is well established that prostate cancer is exposed to fluctuating oxygen tensions and both acute and chronic hypoxia exist, and these conditions can upregulate angiogenesis-associated proteins such as hypoxia-inducible factor 1 alpha and vascular endothelial growth factor A. Low-frequency low-intensity ultrasound with microbubbles can induce obvious microvessel damage in tumors, cause cell necrosis or apoptosis. However, there is no information about whether the blocking blood effect of low-frequency low-intensity ultrasound with microbubbles has an influence on hypoxia environment of prostate cancer. Therefore, we investigated the impact of different low-frequency low-intensity ultrasound with microbubbles radiation times on prostate tumors, observed the change in the hypoxia-inducible factor 1 alpha and vascular endothelial growth factor A protein levels, as well as cell proliferation, apoptosis, and tumor volume. The results indicated that as the radiation was repeated four times on each treatment day, the effects of interruption were durable, the cell proliferation was inhibited, and apoptosis was promoted, and the hypoxia-inducible factor 1 alpha and vascular endothelial growth factor A expression levels were lower in the treatment group than in the control group. When the radiation was carried out once per treatment day, the hypoxia response was stimulated, the hypoxia-inducible factor 1 alpha and vascular endothelial growth factor A expression levels were higher compared with the control group, and cell proliferation was promoted. In addition, the tumor volume increased obviously in the hypoxia-stimulated group, whereas tumors grew slowly in the hypoxia-suppressed group. The results of this work demonstrated that under the same conditions, different radiation times of low-frequency low-intensity ultrasound with microbubbles affect the hypoxia response differently, and the

  2. Regimes of Micro-bubble Formation Using Gas Injection into Ladle Shroud

    Science.gov (United States)

    Chang, Sheng; Cao, Xiangkun; Zou, Zongshu

    2018-06-01

    Gas injection into a ladle shroud is a practical approach to produce micro-bubbles in tundishes, to promote inclusion removal from liquid steel. A semi-empirical model was established to characterize the bubble formation considering the effect of shearing action combined with the non-fully bubble break-up by turbulence. The model shows a good accuracy in predicting the size of bubbles formed in complex flow within the ladle shroud.

  3. Light and ultrasound activated microbubbles around gold nanorods for photoacoustic microsurgery

    Science.gov (United States)

    Cavigli, Lucia; Centi, Sonia; Lai, Sarah; Borri, Claudia; Micheletti, Filippo; Tortoli, Paolo; Panettieri, Ilaria; Streit, Ingolf; Rossi, Francesca; Ratto, Fulvio; Pini, Roberto

    2017-07-01

    Photoacoustic imaging and microsurgery have recently attracted attention for applications in oncology. Here, we present a versatile set-up to trigger vapor microbubbles around plasmonic nanoparticles by a combined light-ultrasound excitation. This system enables the detection and parametrization of bubbles as a function of several variables, such us optical fluence, ultrasound intensity, nanoparticles concentration, thus providing useful directions to the development of new strategies for treatments based on optical cavitation.

  4. Grain destruction in interstellar shocks

    International Nuclear Information System (INIS)

    Seab, C.G.; Shull, J.M.

    1984-01-01

    One of the principal methods for removing grains from the Interstellar Medium is to destroy them in shock waves. Previous theoretical studies of shock destruction have generally assumed only a single size and type of grain; most do not account for the effect of the grain destruction on the structure of the shock. Earlier calculations have been improved in three ways: first, by using a ''complete'' grain model including a distribution of sizes and types of grains; second, by using a self-consistent shock structure that incorporates the changing elemental depletions as the grains are destroyed; and third, by calculating the shock-processed ultraviolet extinction curves for comparison with observations. (author)

  5. The destruction of organic matter

    CERN Document Server

    Gorsuch, T T

    1970-01-01

    International Series of Monographs in Analytical Chemistry, Volume 39: The Destruction of Organic Matter focuses on the identification of trace elements in organic compounds. The monograph first offers information on the processes involved in the determination of trace elements in organic matters, as well as the methods not involving complete destruction of these elements. The text surveys the sources of errors in the processes responsible in pinpointing elements in organic compounds. These processes include sampling, disruption of the samples, manipulation, and measurements. The book

  6. Facilitation of Drug Transport across the Blood–Brain Barrier with Ultrasound and Microbubbles

    Directory of Open Access Journals (Sweden)

    Stephen Meairs

    2015-08-01

    Full Text Available Medical treatment options for central nervous system (CNS diseases are limited due to the inability of most therapeutic agents to penetrate the blood–brain barrier (BBB. Although a variety of approaches have been investigated to open the BBB for facilitation of drug delivery, none has achieved clinical applicability. Mounting evidence suggests that ultrasound in combination with microbubbles might be useful for delivery of drugs to the brain through transient opening of the BBB. This technique offers a unique non-invasive avenue to deliver a wide range of drugs to the brain and promises to provide treatments for CNS disorders with the advantage of being able to target specific brain regions without unnecessary drug exposure. If this method could be applied for a range of different drugs, new CNS therapeutic strategies could emerge at an accelerated pace that is not currently possible in the field of drug discovery and development. This article reviews both the merits and potential risks of this new approach. It assesses methods used to verify disruption of the BBB with MRI and examines the results of studies aimed at elucidating the mechanisms of opening the BBB with ultrasound and microbubbles. Possible interactions of this novel delivery method with brain disease, as well as safety aspects of BBB disruption with ultrasound and microbubbles are addressed. Initial translational research for treatment of brain tumors and Alzheimer’s disease is presented.

  7. Facilitation of Drug Transport across the Blood-Brain Barrier with Ultrasound and Microbubbles.

    Science.gov (United States)

    Meairs, Stephen

    2015-08-31

    Medical treatment options for central nervous system (CNS) diseases are limited due to the inability of most therapeutic agents to penetrate the blood-brain barrier (BBB). Although a variety of approaches have been investigated to open the BBB for facilitation of drug delivery, none has achieved clinical applicability. Mounting evidence suggests that ultrasound in combination with microbubbles might be useful for delivery of drugs to the brain through transient opening of the BBB. This technique offers a unique non-invasive avenue to deliver a wide range of drugs to the brain and promises to provide treatments for CNS disorders with the advantage of being able to target specific brain regions without unnecessary drug exposure. If this method could be applied for a range of different drugs, new CNS therapeutic strategies could emerge at an accelerated pace that is not currently possible in the field of drug discovery and development. This article reviews both the merits and potential risks of this new approach. It assesses methods used to verify disruption of the BBB with MRI and examines the results of studies aimed at elucidating the mechanisms of opening the BBB with ultrasound and microbubbles. Possible interactions of this novel delivery method with brain disease, as well as safety aspects of BBB disruption with ultrasound and microbubbles are addressed. Initial translational research for treatment of brain tumors and Alzheimer's disease is presented.

  8. Preparation of monodisperse microbubbles using an integrated embedded capillary T-junction with electrohydrodynamic focusing.

    Science.gov (United States)

    Parhizkar, Maryam; Stride, Eleanor; Edirisinghe, Mohan

    2014-07-21

    This work investigates the generation of monodisperse microbubbles using a microfluidic setup combined with electrohydrodynamic processing. A basic T-junction microfluidic device was modified by applying an electrical potential difference across the outlet channel. A model glycerol air system was selected for the experiments. In order to investigate the influence of the electric field strength on bubble formation, the applied voltage was increased systematically up to 21 kV. The effect of solution viscosity and electrical conductivity was also investigated. It was found that with increasing electrical potential difference, the size of the microbubbles reduced to ~25% of the capillary diameter whilst their size distribution remained narrow (polydispersity index ~1%). A critical value of 12 kV was found above which no further significant reduction in the size of the microbubbles was observed. The findings suggest that the size of the bubbles formed in the T-junction (i.e. in the absence of the electric field) is strongly influenced by the viscosity of the solution. The eventual size of bubbles produced by the composite device, however, was only weakly dependent upon viscosity. Further experiments, in which the solution electrical conductivity was varied by the addition of a salt indicated that this had a much stronger influence upon bubble size.

  9. Drug perfusion enhancement in tissue model by steady streaming induced by oscillating microbubbles.

    Science.gov (United States)

    Oh, Jin Sun; Kwon, Yong Seok; Lee, Kyung Ho; Jeong, Woowon; Chung, Sang Kug; Rhee, Kyehan

    2014-01-01

    Drug delivery into neurological tissue is challenging because of the low tissue permeability. Ultrasound incorporating microbubbles has been applied to enhance drug delivery into these tissues, but the effects of a streaming flow by microbubble oscillation on drug perfusion have not been elucidated. In order to clarify the physical effects of steady streaming on drug delivery, an experimental study on dye perfusion into a tissue model was performed using microbubbles excited by acoustic waves. The surface concentration and penetration length of the drug were increased by 12% and 13%, respectively, with streaming flow. The mass of dye perfused into a tissue phantom for 30s was increased by about 20% in the phantom with oscillating bubbles. A computational model that considers fluid structure interaction for streaming flow fields induced by oscillating bubbles was developed, and mass transfer of the drug into the porous tissue model was analyzed. The computed flow fields agreed with the theoretical solutions, and the dye concentration distribution in the tissue agreed well with the experimental data. The computational results showed that steady streaming with a streaming velocity of a few millimeters per second promotes mass transfer into a tissue. © 2013 Published by Elsevier Ltd.

  10. Acoustic microstreaming due to an ultrasound contrast microbubble near a wall

    Science.gov (United States)

    Mobadersany, Nima; Sarkar, Kausik

    2017-11-01

    In an ultrasound field, in addition to the sinusoidal motion of fluid particles, particles experience a steady streaming velocity due to nonlinear second order effects. Here, we have simulated the microstreaming flow near a plane rigid wall caused by the pulsations of contrast microbubbles. Although these microbubbles were initially developed as a contrast enhancing agents for ultrasound imaging, they generate additional therapeutic effects that can be harnessed for targeted drug delivery or blood brain barrier (BBB) opening. The microbubbles have a gas core coated with a stabilizing layer of lipids or proteins. We use analytical models as well as boundary element (BEM) simulation to simulate the flow around these bubbles implementing interfacial rheology models for the coating. The microstreaming flow is characterized by two wall bounded vortices. The size of the vortices decreases with the decrease of the separation from the wall. The vortex-induced shear stress is simulated and analyzed as a function of excitation parameters and geometry. These microstreaming shear stress plays a critical role in increasing the membrane permeability facilitating drug delivery or rupturing biological tissues.

  11. Optimization and characterization of stable lipid-based, oxygen-filled microbubbles by mixture design.

    Science.gov (United States)

    Polizzotti, Brian D; Thomson, Lindsay M; O'Connell, Daniel W; McGowan, Francis X; Kheir, John N

    2014-08-01

    Tissue hypoxia is a final common pathway that leads to cellular injury and death in a number of critical illnesses. Intravenous injections of self-assembling, lipid-based oxygen microbubbles (LOMs) can be used to deliver oxygen gas, preventing organ injury and death from systemic hypoxemia. However, current formulations exhibit high polydispersity indices (which may lead to microvascular obstruction) and poor shelf-lives, limiting the translational capacity of LOMs. In this study, we report our efforts to optimize LOM formulations using a mixture response surface methodology (mRSM). We study the effect of changing excipient proportions (the independent variables) on microbubble diameter and product loss (the dependent variables). By using mRSM analysis, the experimental data were fit using a reduced Scheffé linear mixture model. We demonstrate that formulations manufactured from 1,2-distearoyl-sn-glycero-3-phosphocholine, corn syrup, and water produce micron-sized microbubbles with low polydispersity indices, and decreased product loss (relative to previously described formulations) when stored at room temperature over a 30-day period. Optimized LOMs were subsequently tested for their oxygen-releasing ability and found to have similar release kinetics as prior formulations. © 2014 Wiley Periodicals, Inc.

  12. Quantitation of MRI sensitivity to quasi-monodisperse microbubble contrast agents for spatially resolved manometry.

    Science.gov (United States)

    Bencsik, Martin; Al-Rwaili, Amgad; Morris, Robert; Fairhurst, David J; Mundell, Victoria; Cave, Gareth; McKendry, Jonathan; Evans, Stephen

    2013-11-01

    The direct in-vivo measurement of fluid pressure cannot be achieved with MRI unless it is done with the contribution of a contrast agent. No such contrast agents are currently available commercially, whilst those demonstrated previously only produced qualitative results due to their broad size distribution. Our aim is to quantitate then model the MR sensitivity to the presence of quasi-monodisperse microbubble populations. Lipid stabilised microbubble populations with mean radius 1.2 ± 0.8 μm have been produced by mechanical agitation. Contrast agents with increasing volume fraction of bubbles up to 4% were formed and the contribution the bubbles bring to the relaxation rate was quantitated. A periodic pressure change was also continuously applied to the same contrast agent, until MR signal changes were only due to bubble radius change and not due to a change in bubble density. The MR data compared favourably with the prediction of an improved numerical simulation. An excellent MR sensitivity of 23 % bar(-1) has been demonstrated. This work opens up the possibility of generating microbubble preparations tailored to specific applications with optimised MR sensitivity, in particular MRI based in-vivo manometry. Copyright © 2012 Wiley Periodicals, Inc.

  13. Spatiotemporal evolution of cavitation dynamics exhibited by flowing microbubbles during ultrasound exposure.

    Science.gov (United States)

    Choi, James J; Coussios, Constantin-C

    2012-11-01

    Ultrasound and microbubble-based therapies utilize cavitation to generate bioeffects, yet cavitation dynamics during individual pulses and across consecutive pulses remain poorly understood under physiologically relevant flow conditions. SonoVue(®) microbubbles were made to flow (fluid velocity: 10-40 mm/s) through a vessel in a tissue-mimicking material and were exposed to ultrasound [frequency: 0.5 MHz, peak-rarefactional pressure (PRP): 150-1200 kPa, pulse length: 1-100,000 cycles, pulse repetition frequency (PRF): 1-50 Hz, number of pulses: 10-250]. Radiated emissions were captured on a linear array, and passive acoustic mapping was used to spatiotemporally resolve cavitation events. At low PRPs, stable cavitation was maintained throughout several pulses, thus generating a steady rise in energy with low upstream spatial bias within the focal volume. At high PRPs, inertial cavitation was concentrated in the first 6.3 ± 1.3 ms of a pulse, followed by an energy reduction and high upstream bias. Multiple pulses at PRFs below a flow-dependent critical rate (PRF(crit)) produced predictable and consistent cavitation dynamics. Above the PRF(crit), energy generated was unpredictable and spatially biased. In conclusion, key parameters in microbubble-seeded flow conditions were matched with specific types, magnitudes, distributions, and durations of cavitation; this may help in understanding empirically observed in vivo phenomena and guide future pulse sequence designs.

  14. Molecular evaluation of thrombosis using X-ray phase contrast imaging with microbubbles targeted to P-selectin in mice

    International Nuclear Information System (INIS)

    Tang, Rongbiao; Chai, Wei-Min; Yan, Fuhua; Chen, Ke-Min; Yang, Guo-Yuan

    2016-01-01

    X-ray phase contrast imaging (PCI) provides excellent image contrast by utilizing the phase shift. The introduction of microbubbles into tissues can cause a phase shift to make microbubbles visibly identified on PCI. In this study, we assessed the feasibility of targeted microbubble-based PCI for the detection of thrombosis. The absorption and phase contrast images of P-selectin-targeted microbubbles (MB P ) were obtained and compared in vitro. MB P , control IgG-targeted microbubbles (MB C ), and unbound microbubbles (MB U ) were tested for binding specificity on thrombi expressing P-selectin. MB P were used as molecular PCI probes to evaluate P-selectin expression in a mouse model of arteriovenous shunt thrombosis that was created using PE tubes in the bypass outside of the mouse body. PCI clearly showed the microbubbles not viewable via absorption contrast imaging (ACI). In vitro attachment of MB P (91.60 ± 11.63) to thrombi was significantly higher than attachment of MB C (17.80 ± 4.02, P < 0.001) or MB U (9.80 ± 2.59, P < 0.001). In the mouse model of arteriovenous shunt thrombosis, the binding affinity of MB P (15.50 ± 6.25) was significantly greater than that of MB C (0.50 ± 0.84, P < 0.001) or MB U (0.33 ± 0.52, P < 0.001). Our results indicate that molecular PCI may be considered as a novel and promising imaging modality for the investigation of thrombosis. (orig.)

  15. T cell-mediated hepatitis in mice infected with lymphocytic choriomeningitis virus. Liver cell destruction by H-2 class I-restricted virus-specific cytotoxic T cells as a physiological correlate of the 51Cr-release assay

    International Nuclear Information System (INIS)

    Zinkernagel, R.M.; Haenseler, E.; Leist, T.; Cerny, A.; Hengartner, H.; Althage, A.

    1986-01-01

    A model for immunologically T cell-mediated hepatitis was established in mice infected with lymphocytic choriomeningitis virus (LCMV). The severity of hepatitis was monitored histologically and by determination of changes in serum levels of the enzymes alanine aminotransferase (ALT), aspartate aminotransferase (AST), glutamate dehydrogenase (GLDH), and alkaline phosphatase (AP). Kinetics of histological disease manifestations, increases of liver enzyme levels in the serum, and cytotoxic T cell activities in livers and spleens all correlated and were dependent upon several parameters: LCMV-isolate; LCMV-WE caused extensive hepatitis, LCMV-Armstrong virtually none. Virus dose. Route of infection; i.v. or i.p. infection caused hepatitis, whereas infection into the footpad did not. The general genetic background of the murine host; of the strains tested, Swiss mice and A-strain mice were more susceptible than C57BL or CBA mice; BALB/c and DBA/2 mice were least susceptible. The degree of immunocompetence of the murine host; T cell deficient nu/nu mice never developed hepatitis, whereas nu/+ or +/+ mice always did. B cell-depleted anti-IgM-treated mice developed immune-mediated hepatitis comparably or even more extensively than control mice. Local cytotoxic T cell activity; mononuclear cells isolated from livers during the period of overt hepatitis were two to five times more active than equal numbers of spleen cells. Adoptive transfer of nylon wool-nonadherent anti-Thy-1.2 and anti-Lyt-2 plus C-sensitive, anti-L3T4 plus C-resistant lymphocytes into irradiated mice preinfected with LCMV-WE caused a rapid time- and dose-dependent linear increase of serum enzyme levels. This increase was caused by adoptive transfer of lymphocytes if immune cell donors and recipient mice shared class I, but not when they shared class II histocompatibility antigens

  16. Conceptualizing Chronic Self-Destructiveness.

    Science.gov (United States)

    Kelley, Kathryn

    Self-destructiveness can be viewed in two ways: as performing an act which one knows cognitively is not conducive to one's welfare but nonetheless leads to some pleasurable affect (e.g., overeating, smoking); or not performing an act one knows one should perform but which has some negative affective consequences (e.g., dental checkups, saving…

  17. Animal Spirits Meets Creative Destruction

    NARCIS (Netherlands)

    Francois, P.; Lloyd-Ellis, H.

    2001-01-01

    We show how a Schumpeterian process of creative destruction can induce coordination in the timing of entrepreneurial activities across diverse sectors of the economy.Consequently, a multi-sector economy, in which sector-specific, productivity improvements are made by independent, profit-seeking

  18. Dynamic Scoring Through Creative Destruction

    NARCIS (Netherlands)

    van Oudheusden, P.

    2012-01-01

    Abstract: We examine the dynamic feedback effects of fiscal policies on the government budget and economy activity in a calibrated general equilibrium framework featuring endogenous growth through creative destruction. For several European countries, we find that making tax incentives with respect

  19. Exergy destruction in ammonia scrubbers

    NARCIS (Netherlands)

    Zisopoulos, Filippos K.; Goot, van der Atze Jan; Boom, Remko M.

    2018-01-01

    A theoretical ammonia scrubbing process by sulfuric acid solution is assessed with the concept of exergy. The exergy destruction of chemical neutralization is mainly (75–94%) due to changes in the chemical exergy of streams and thermal effects from the reaction while mixing effects have a limited

  20. Ultrasound-mediated drug delivery by gas bubbles generated from a chemical reaction.

    Science.gov (United States)

    Lee, Sungmun; Al-Kaabi, Leena; Mawart, Aurélie; Khandoker, Ahsan; Alsafar, Habiba; Jelinek, Herbert F; Khalaf, Kinda; Park, Ji-Ho; Kim, Yeu-Chun

    2018-02-01

    Highly echogenic and ultrasound-responsive microbubbles such as nitrogen and perfluorocarbons have been exploited as ultrasound-mediated drug carriers. Here, we propose an innovative method for drug delivery using microbubbles generated from a chemical reaction. In a novel drug delivery system, luminol encapsulated in folate-conjugated bovine serum albumin nanoparticles (Fol-BSAN) can generate nitrogen gas (N 2 ) by chemical reaction when it reacts with hydrogen peroxide (H 2 O 2 ), one of reactive oxygen species (ROS). ROS plays an important role in the initiation and progression of cancer and elevated ROS have been observed in cancer cells both in vitro and in vivo. High-intensity focussed ultrasound (HIFU) is used to burst the N 2 microbubbles, causing site-specific delivery of anticancer drugs such as methotrexate. In this research, the drug delivery system was optimised by using water-soluble luminol and Mobil Composition of Matter-41 (MCM-41), a mesoporous material, so that the delivery system was sensitive to micromolar concentrations of H 2 O 2 . HIFU increased the drug release from Fol-BSAN by 52.9 ± 2.9% in 10 minutes. The cytotoxicity of methotrexate was enhanced when methotrexate is delivered to MDA-MB-231, a metastatic human breast cancer cell line, using Fol-BSAN with HIFU. We anticipate numerous applications of chemically generated microbubbles for ultrasound-mediated drug delivery.

  1. Transient permeabilization of cell membranes by ultrasound-exposed microbubbles is related to formation of hydrogen peroxide.

    Science.gov (United States)

    Juffermans, L J M; Dijkmans, P A; Musters, R J P; Visser, C A; Kamp, O

    2006-10-01

    In the present study, we addressed the interactions among ultrasound, microbubbles, and living cells as well as consequent arising bioeffects. We specifically investigated whether hydrogen peroxide (H(2)O(2)) is involved in transient permeabilization of cell membranes in vitro after ultrasound exposure at low diagnostic power, in the presence of stable oscillating microbubbles, by measuring the generation of H(2)O(2) and Ca(2+) influx. Ultrasound, in the absence or presence of SonoVue microbubbles, was applied to H9c2 cells at 1.8 MHz with a mechanical index (MI) of 0.1 or 0.5 during 10 s. This was repeated every minute, for a total of five times. The production of H(2)O(2) was measured intracellularly with CM-H(2)DCFDA. Cell membrane permeability was assessed by measuring real-time changes in intracellular Ca(2+) concentration with fluo-4 using live-cell fluorescence microscopy. Ultrasound, in the presence of microbubbles, caused a significant increase in intracellular H(2)O(2) at MI 0.1 of 50% and MI 0.5 of 110% compared with control (P ultrasound exposure was completely blocked at MI 0.1 (P ultrasound-exposed microbubbles.

  2. Hemostatic mechanism underlying microbubble-enhanced non-focused ultrasound in the treatment of a rabbit liver trauma model

    Science.gov (United States)

    Zhao, Da-wei; Tian, Meng; Yang, Jian-zheng; Du, Peng; Bi, Jie; Zhu, Xinjian

    2016-01-01

    The aim of our study was to investigate the hemostatic mechanism underlying microbubble-enhanced non-focused ultrasound treatment of liver trauma. Thirty rabbits with liver trauma were randomly divided into three groups—the microbubble-enhanced ultrasound (MEUS; further subdivided based on exposure intensity into MEUS1 [0.11 W/cm2], MEUS2 [0.55 W/cm2], and MEUS3 [1.1 W/cm2]), ultrasound without microbubbles (US), and microbubbles without ultrasound (MB) groups. The pre- and post-treatment bleeding weight and visual bleeding scores were evaluated. The serum liver enzyme concentrations as well as the blood perfusion level represented by mean peak contrast intensity (PI) ratio in the treatment area were analyzed. The hemostatic mechanism was evaluated by histological and transmission electron microscopic examination of liver tissue samples. The MEUS subgroups 1–3 (grade 0–1, grade 0–2, and grade 1–2, respectively) exhibited significantly lower post-treatment visual bleeding scores than the US and MB groups (both, grade 3–4; all, P hepatic cells became edematous and compressed the hepatic sinus and associated blood vessels. However, the serum liver enzyme levels were not significantly altered. Microbubble-enhanced non-focused ultrasound does not significantly affect blood perfusion and liver function and can be used to induce rapid hemostasis in case of liver trauma. PMID:27633577

  3. Total destruction of PCB transformers

    International Nuclear Information System (INIS)

    Myers, D.S.

    1991-01-01

    This paper reports that if elimination of PCB liability, including lingering liabilities, is the goal, then landfilling cannot be and option. The law is clear that the generator of PCB waste is responsible for that waste until this destruction. Landfilling is not destruction. Retrofilling as askarel units will not get rid of all PCB liabilities, either. Askarel retrofilling can only make this claim when it can give a lifetime guaranty of no detectable PCBs. States like Washington and California regulate, as hazardous waste, fluids which contain greater than 2 and 5 ppm PCB, respectively. There is no guarantee that your state will not so regulate PCBs in the future or that the federal laws might tighten up. Therefore, replacement and disposal by Resource Recovery constitutes the only lifetime guarantee on the market that the PCBs in your askarel transformers will never come back to haunt you

  4. Defining Weapons of Mass Destruction

    Science.gov (United States)

    2012-01-01

    Cyprus, Liberia, Malta, Marshall Islands , Mongolia, Panama, and St. Vin- cent and the Grenadines, according to a State Department summary available...1972 Biological and Toxin Weapons Convention, and the 1993 Chemical Weapons Convention. As such, NBC weapons represent a group of weapons that the...Development, Produc- tion and Stockpiling of Bacteriological (Biological) and Toxin Weapons and on Their Destruction contains two references to WMD

  5. Chondrule destruction in nebular shocks

    Energy Technology Data Exchange (ETDEWEB)

    Jacquet, Emmanuel; Thompson, Christopher, E-mail: ejacquet@mnhn.fr [Canadian Institute for Theoretical Astrophysics, University of Toronto, 60 St George Street, Toronto, ON M5S 3H8 (Canada)

    2014-12-10

    Chondrules are millimeter-sized silicate spherules ubiquitous in primitive meteorites, but whose origin remains mysterious. One of the main proposed mechanisms for producing them is melting of solids in shock waves in the gaseous protoplanetary disk. However, evidence is mounting that chondrule-forming regions were enriched in solids well above solar abundances. Given the high velocities involved in shock models, destructive collisions would be expected between differently sized grains after passage of the shock front as a result of differential drag. We investigate the probability and outcome of collisions of particles behind a one-dimensional shock using analytic methods as well as a full integration of the coupled mass, momentum, energy, and radiation equations. Destruction of protochondrules seems unavoidable for solid/gas ratios ε ≳ 0.1, and possibly even for solar abundances because of 'sandblasting' by finer dust. A flow with ε ≳ 10 requires much smaller shock velocities (∼2 versus 8 km s{sup –1}) in order to achieve chondrule-melting temperatures, and radiation trapping allows slow cooling of the shocked fragments. Initial destruction would still be extensive; although re-assembly of millimeter-sized particles would naturally occur by grain sticking afterward, the compositional heterogeneity of chondrules may be difficult to reproduce. We finally note that solids passing through small-scale bow shocks around few kilometer-sized planetesimals might experience partial melting and yet escape fragmentation.

  6. Destructive analysis and evaluation services

    International Nuclear Information System (INIS)

    Kuhn, E.; Lemaire, R.; Wenzel, U.; Aigner, H.; Bagliano, G.; Deron, S.; Jordan, L.

    1986-07-01

    This manual describes the procedures for independent verification measurements by Destructive Analysis as required by the Divisions of Operations. It includes the relevant instructions and information necessary to achieve the verification from sampling through final use of the evaluation results. It is a working/reference document for the Inspectors and for the supporting units, as well as a training manual for Inspectors which brings together all the necessary information for verification by Destructive Analysis. This manual gives information essential to the Inspector and to the units of the Safeguards Analytical Services (SAS) in the following areas: material stratification, sampling, sample conditioning and data collection; packaging, transporting, tracking, receipt and analysis of samples; and evaluation and final use of the evaluation results. This information is provided as: specific instructions and/or examples; summaries of relevant, existing documents; and references to existing documents. Forms are available for sample, item and stratum data collection as well as for transfer of samples and for the reporting of results. A complete typical example package of the documents related to the verification by Destructive Analysis is included. In addition, summaries of the analytical procedures used at the Safeguards Analytical Laboratory (SAL) of the IAEA and the expected measurement performance for element assay and isotopic abundance are provided. (author)

  7. Cell Lysis and Detoxification of Cyanotoxins Using a Novel Combination of Microbubble Generation and Plasma Microreactor Technology for Ozonation

    Directory of Open Access Journals (Sweden)

    Jagroop Pandhal

    2018-04-01

    Full Text Available There has been a steady rise in the incidences of algal blooms globally, and worryingly, there is increasing evidence that changes in the global climate are leading to a shift toward cyanobacterial blooms. Many cyanobacterial genera are harmful, producing several potent toxins, including microcystins, for which there are over 90 described analogues. There are a wide range of negative effects associated with these toxins including gastroenteritis, cytotoxicity, hepatotoxicity and neurotoxicity. Although a variety of oxidation based treatment methods have been described, ozonation and advanced oxidation are acknowledged as most effective as they readily oxidise microcystins to non-toxic degradation products. However, most ozonation technologies have challenges for scale up including high costs and sub-optimum efficiencies, hence, a low cost and scalable ozonation technology is needed. Here we designed a low temperature plasma dielectric barrier discharge (DBD reactor with an incorporated fluidic oscillator for microbubble delivery of ozone. Both technologies have the potential to drastically reduce the costs of ozonation at scale. Mass spectrometry analysis revealed very rapid (<2 min destruction of two pure microcystins (MC-LR and MC-RR, together with removal of by-products even at low flow rate 1 L min−1 where bubble size was 0.56–0.6 mm and the ozone concentration within the liquid was 20 ppm. Toxicity levels were calculated through protein phosphatase inhibition assays and indicated loss of toxicity as well as confirming the by-products were also non-toxic. Finally, treatment of whole Microcystis aeruginosa cells showed that even at these very low ozone levels, cells can be killed and toxins (MC-LR and Desmethyl MC-LR removed. Little change was observed in the first 20 min of treatment followed by rapid increase in extracellular toxins, indicating cell lysis, with most significant release at the higher 3 L min−1 flow rate compared to 1 L

  8. The multiphase flow system used in exploiting depleted reservoirs: water-based Micro-bubble drilling fluid

    International Nuclear Information System (INIS)

    Zheng Lihui; He Xiaoqing; Wang Xiangchun; Fu Lixia

    2009-01-01

    Water-based micro-bubble drilling fluid, which is used to exploit depleted reservoirs, is a complicated multiphase flow system that is composed of gas, water, oil, polymer, surfactants and solids. The gas phase is separate from bulk water by two layers and three membranes. They are 'surface tension reducing membrane', 'high viscosity layer', 'high viscosity fixing membrane', 'compatibility enhancing membrane' and 'concentration transition layer of liner high polymer (LHP) and surfactants' from every gas phase centre to the bulk water. 'Surface tension reducing membrane', 'high viscosity layer' and 'high viscosity fixing membrane' bond closely to pack air forming 'air-bag', 'compatibility enhancing membrane' and 'concentration transition layer of LHP and surfactants' absorb outside 'air-bag' to form 'incompact zone'. From another point of view, 'air-bag' and 'incompact zone' compose micro-bubble. Dynamic changes of 'incompact zone' enable micro-bubble to exist lonely or aggregate together, and lead the whole fluid, which can wet both hydrophilic and hydrophobic surface, to possess very high viscosity at an extremely low shear rate but to possess good fluidity at a higher shear rate. When the water-based micro-bubble drilling fluid encounters leakage zones, it will automatically regulate the sizes and shapes of the bubbles according to the slot width of fracture, the height of cavern as well as the aperture of openings, or seal them by making use of high viscosity of the system at a very low shear rate. Measurements of the rheological parameters indicate that water-based micro-bubble drilling fluid has very high plastic viscosity, yield point, initial gel, final gel and high ratio of yield point and plastic viscosity. All of these properties make the multiphase flow system meet the requirements of petroleum drilling industry. Research on interface between gas and bulk water of this multiphase flow system can provide us with information of synthesizing effective

  9. Dynamic manipulation of the subharmonic scattering of phospholipid-coated microbubbles

    Energy Technology Data Exchange (ETDEWEB)

    Faez, Telli; Renaud, Guillaume; De Jong, Nico [Biomedical Engineering Thoraxcenter, Erasmus Medical Center, PO Box 2040, 3000 CA Rotterdam (Netherlands); Defontaine, Marielle; Calle, Samuel, E-mail: t.faez@erasmusmc.nl [INSERM U930-CNRS ERL3106, Universite Francois Rabelais, UFR Medecine, 10 bd Tonnelle, 37000 Tours (France)

    2011-10-07

    In this paper, the influence of a dynamic variation in the ambient pressure on the subharmonic response of phospholipid-coated microbubbles was investigated. The ambient pressure in water was modulated by a 2.5 kHz acoustic wave with a peak amplitude of 15 kPa. We investigated the fundamental and subharmonic emissions at two driving frequencies: 5 and 10 MHz. The modulation of the bubble radius induced by the dynamic variation in the liquid ambient pressure subsequently causes modulations of the scattered acoustic pressure at the fundamental and subharmonic frequencies (half the fundamental frequency). As a first result, we measured that the variation in the ambient pressure of 15 kPa can modulate the subharmonic amplitude up to 10 dB as compared to the static atmospheric pressure condition. As a second result, we noticed that the relative subharmonic amplitude modulation as a function of the LF acoustic pressure was symmetrical for the 5 MHz driving frequency but asymmetric for 10 MHz. In the latter case, the subharmonic amplitude was more enhanced for an ambient overpressure than reduced for an ambient depression of the same amplitude likely due to the buckling of the lipid shell. However, the fundamental amplitude was symmetrically modulated during bubble compression and expansion. Moreover, subharmonic and fundamental amplitude modulations were found to be either in phase or out of phase with the low-frequency acoustic pressure. Numerical simulations showed that this behavior can be obtained depending on the bubbles' diameter. The highest subharmonic amplitude was measured when microbubbles were insonified at 10 MHz. This fact together with the asymmetry observed in the subharmonic modulation suggests that smaller bubbles with a buckling shell are excited at 10 MHz compared to 5 MHz. These results present new potentials for in vitro characterization of contrast agent microbubbles and possibly a new imaging modality.

  10. Microbubble-based enhancement of radiation effect: Role of cell membrane ceramide metabolism.

    Directory of Open Access Journals (Sweden)

    Azza Al-Mahrouki

    Full Text Available Ultrasound (US stimulated microbubbles (MB is a new treatment approach that sensitizes cancer cells to radiation (XRT. The molecular pathways in this response remain unelucidated, however, previous data has supported a role for cell membrane-metabolism related pathways including an up regulation of UDP glycosyltransferase 8 (UGT8, which catalyzes the transfer of galactose to ceramide, a lipid that is associated with the induction of apoptotic signalling. In this study, the role of UGT8 in responses of prostate tumours to ultrasound-stimulated microbubble radiation enhancement therapy is investigated. Experiments were carried out with cells in vitro and tumours in vivo in which UGT8 levels had been up regulated or down regulated. Genetically modified PC3 cells were treated with XRT, US+MB, or a combination of XRT+US+MB. An increase in the immunolabelling of ceramide was observed in cells where UGT8 was down-regulated as opposed to cells where UGT8 was either not regulated or was up-regulated. Clonogenic assays have revealed a decreased level of cellular survival with the down-regulation of UGT8. Xenograft tumours generated from stably transfected PC3 cells were also treated with US+MB, XRT or US+MB+XRT. Histology demonstrated more cellular damage in tumours with down-regulated UGT8 in comparison with control tumours. In contrast, tumours with up-regulated UGT8 had less damage than control tumours. Power Doppler imaging indicated a reduction in the vascular index with UGT8 down-regulation and photoacoustic imaging revealed a reduction in oxygen saturation. This was contrary to when UGT8 was up regulated. The down regulation of UGT8 led to the accumulation of ceramide resulting in more cell death signalling and therefore, a greater enhancement of radiation effect when vascular disruption takes place through the use of ultrasound-stimulated microbubbles.

  11. An algorithm for sensing venous oxygenation using ultrasound-modulated light enhanced by microbubbles

    Science.gov (United States)

    Honeysett, Jack E.; Stride, Eleanor; Deng, Jing; Leung, Terence S.

    2012-02-01

    Near-infrared spectroscopy (NIRS) can provide an estimate of the mean oxygen saturation in tissue. This technique is limited by optical scattering, which reduces the spatial resolution of the measurement, and by absorption, which makes the measurement insensitive to oxygenation changes in larger deep blood vessels relative to that in the superficial tissue. Acousto-optic (AO) techniques which combine focused ultrasound (US) with diffuse light have been shown to improve the spatial resolution as a result of US-modulation of the light signal, however this technique still suffers from low signal-to-noise when detecting a signal from regions of high optical absorption. Combining an US contrast agent with this hybrid technique has been proposed to amplify an AO signal. Microbubbles are a clinical contrast agent used in diagnostic US for their ability to resonate in a sound field: in this work we also make use of their optical scattering properties (modelled using Mie theory). A perturbation Monte Carlo (pMC) model of light transport in a highly absorbing blood vessel containing microbubbles surrounded by tissue is used to calculate the AO signal detected on the top surface of the tissue. An algorithm based on the modified Beer-Lambert law is derived which expresses intravenous oxygen saturation in terms of an AO signal. This is used to determine the oxygen saturation in the blood vessel from a dual wavelength microbubble-contrast AO measurement. Applying this algorithm to the simulation data shows that the venous oxygen saturation is accurately recovered, and this measurement is robust to changes in the oxygenation of the superficial tissue layer.

  12. Estimation of mechanical properties of gelatin using a microbubble under acoustic radiation force

    International Nuclear Information System (INIS)

    Shirota, Eriko; Ando, Keita

    2015-01-01

    This paper is concerned with observations of the translation of a microbubble (80 μm or 137 μm in radius) in a viscoelastic medium (3 w% gelatin), which is induced by acoustic radiation force originating from 1 MHz focused ultrasound. An optical system using a high-speed camera was designed to visualize the bubble translation and deformation. If the bubble remains its spherical shape under the sonication, the bubble translation we observed can be described by theory based on the Voigt model for linear viscoelastic solids; mechanical properties of the gelatin are calculated from measurements of the terminal displacement under the sonication. (paper)

  13. Scaling behavior of microbubbles rising in water-saturated porous media

    Science.gov (United States)

    Kong, X.; Ma, Y.; Scheuermann, A.; Bringemeier, D.; Galindo-Torres, S. A.; Saar, M. O.; Li, L.

    2015-12-01

    Gas transport in the form of discrete microbubbles in saturated porous media is of importance in a number of processes relevant to many geo-environmental and engineering systems such as bubbling of greenhouse gases in river and sea beds, hydrocarbon gas migration in coal cleats and rock fractures, and air sparging for remediation of soil contaminated with volatile organic compounds. Under the assumption of no or minor volume expansion during gravity-driven migration, the transport of a single microbubble can be well described using various drag force models. However, not enough attention has been paid to the collective behavior of microbubbles during their ascend as a plume through the saturated porous medium, involving dynamic interactions between individual bubbles, bubbles and the ambient fluid, as well as bubbles and the solid matrix. With our quasi-2D, lab-scale microbubble migration experiments, where bubbles are continuously released from a diffuser at the bottom of a porous bed of hydrated gel beads, we establish a scaling relationship between the gas (bubble) release rate and various characteristic parameters of the bubble plume, such as plume tip velocity, plume width, and breakthrough time of the plume front. We find that the characteristic width of the bubble plume varies as a power of both the gas release rate and the bed thickness, with exponents of 0.2 and 0.4, respectively. Moreover, the characteristic breakthrough time also scales with both the gas release rate and the bed thickness with power-law exponents of -0.4 and 1.2, respectively. The mean pore-water velocity of the circulating ambient water also follows a power-law relationship with the gas release rate being an exponent of 0.6 of the gas release rate. This can be quantitatively proven using a simplified momentum exchange model together with the above power-law exponents for the bubble plume. These analyses on the experimental results are carried out on the basis of non

  14. Resonance Frequency of Optical Microbubble Resonators: Direct Measurements and Mitigation of Fluctuations

    Directory of Open Access Journals (Sweden)

    Alessandro Cosci

    2016-08-01

    Full Text Available This work shows the improvements in the sensing capabilities and precision of an Optical Microbubble Resonator due to the introduction of an encaging poly(methyl methacrylate (PMMA box. A frequency fluctuation parameter σ was defined as a score of resonance stability and was evaluated in the presence and absence of the encaging system and in the case of air- or water-filling of the cavity. Furthermore, the noise interference introduced by the peristaltic and the syringe pumping system was studied. The measurements showed a reduction of σ in the presence of the encaging PMMA box and when the syringe pump was used as flowing system.

  15. Experience destructive therapy anogenital warts

    Directory of Open Access Journals (Sweden)

    M. R. Rahmatulina

    2016-01-01

    Full Text Available Objective. To assess the efficiency and tolerability of the Mardil Zinc Max, solution for external application, in topical therapy of patients with anogenital warts. Materials and methods. The study involved 58 women and 12 men at the age of 18 to 57 years old, suffering from anogenital warts. the diagnosis was confirmed by identification of human papillomavirus by the polymerase chain reaction in real time. All the patients were treated by the chemical destruction of anogenital warts with the 1.5% solution of zinc chloropropionate in 50% 2-chloropropionic acid (Mardil Zinc Max by a single application of the solution on the pathological eruptions. The results of treatment were assessed in 2 weeks, in 1, 3, 6 and 9 months after the destructive therapy. Results. In 2 weeks 62 (88.6% patients showed a clinical cure with complete tissue regeneration in the lesions, in 8 (11,4% cases in areas of the preparation erosions were visualized in the epithelialization phase, and they completely resolved within 1 week. recurrences of anogenital warts were detected in 1 (1,4% patient in the observation period up to 3 months and in 2 (2,8% patients during 9 months after carrying out the destruction. Adverse drug events have not been identified in the course of therapy and follow-up. Conclusions. As a result of the treatment of anogenital warts with the Mardil Zinc Max high rate of performance and security was set (100%, as well as the low percentage (4,2% of development of relapses.

  16. Inhibition of prostate cancer growth using doxorubicin assisted by ultrasound-targeted nanobubble destruction

    Directory of Open Access Journals (Sweden)

    Fan X

    2016-07-01

    Full Text Available Xiaozhou Fan,1,* Luofu Wang,2,* Yanli Guo,1 Xingyu Xiong,1 Lianhua Zhu,1 Kejing Fang1 1Department of Ultrasound, Southwest Hospital, 2Department of Urology, Daping Hospital, Third Military Medical University, Chongqing, People’s Republic of China *These authors contributed equally to this work Abstract: Ultrasound (US-targeted microbubble destruction has been widely used as an effective drug-delivery system. However, nanobubbles (NBs have better stability and stronger penetration than microbubbles, and drug delivery assisted by US-targeted NB destruction (UTND still needs to be investigated. Our aim was to investigate the effect of doxorubicin (DOX on the inhibition of prostate cancer growth under UTND. Contrast-enhanced US imaging of transplanted PC3 prostate cancer in mice showed that under a combination of 1 W/cm2 US power and a 100 Hz intermittent pulse with a “5 seconds on, 5 seconds off” mode, NBs with an average size of (485.7±33 nm were effectively destroyed within 15 minutes in the tumor location. PC3 cells and 20 tumor-bearing mice were divided into four groups: a DOX group, a DOX + NB group, a DOX + US group, and a DOX + NB + US group. The cell growth-inhibition rate and DOX concentration of xenografts in the DOX + NB + US group were highest. Based on another control group and these four groups, another 25 tumor-bearing mice were used to observe the treatment effect of nine DOX injections under UTND. The xenografts in the DOX + NB + US group decreased more obviously and had more cellular apoptosis than other groups. Finally, electron microscopy was used to estimate the cavitation effect of NBs under US irradiation in the control group, NB group, US group, and NB + US group. The results of scanning electron microscopy showed that PC3 cells in the DOX + NB + US group had more holes and significantly increased cell-surface folds. Meanwhile, transmission electric microscopy confirmed that more lanthanum nitrate particles entered

  17. Longitudinal Relations Between Constructive and Destructive Conflict and Couples’ Sleep

    Science.gov (United States)

    El-Sheikh, Mona; Koss, Kalsea J.; Kelly, Ryan J.; Rauer, Amy J.

    2016-01-01

    We examined longitudinal relations between interpartner constructive (negotiation) and destructive (psychological and physical aggression) conflict strategies and couples’ sleep over 1 year. Toward explicating processes of effects, we assessed the intervening role of internalizing symptoms in associations between conflict tactics and couples’ sleep. Participants were 135 cohabiting couples (M age = 37 years for women and 39 years for men). The sample included a large representation of couples exposed to economic adversity. Further, 68% were European American and the remainder were primarily African American. At Time 1 (T1), couples reported on their conflict and their mental health (depression, anxiety). At T1 and Time 2, sleep was examined objectively with actigraphs for 7 nights. Three sleep parameters were derived: efficiency, minutes, and latency. Actor–partner interdependence models indicated that husbands’ use of constructive conflict forecasted increases in their own sleep efficiency as well as their own and their wives’ sleep duration over time. Actor and partner effects emerged, and husbands’ and wives’ use of destructive conflict strategies generally predicted worsening of some sleep parameters over time. Several mediation and intervening effects were observed for destructive conflict strategies. Some of these relations reveal that destructive conflict is associated with internalizing symptoms, which in turn are associated with some sleep parameters longitudinally. These findings build on a small, albeit growing, literature linking sleep with marital functioning, and illustrate that consideration of relationship processes including constructive conflict holds promise for gaining a better understanding of factors that influence the sleep of men and women. PMID:25915089

  18. Nilotinib-Associated Destructive Thyroiditis

    Directory of Open Access Journals (Sweden)

    Suhalia Bakerywala

    2015-01-01

    Full Text Available Protein tyrosine kinase inhibitors are currently an important drug class in the treatment of leukemia. They represent targeted cancer therapy and have become the treatment of choice in chronic myeloid leukemia. Tyrosine kinases are enzymes expressed in multiple tissues and are involved in several signaling pathways influencing cellular growth. Below we describe a patient who developed an unusual complication of tyrosine kinase inhibitor therapy: thyrotoxicosis due to destructive thyroiditis. We review the pathophysiology of tyrosine kinase inhibitor-induced thyroid dysfunction particularly with regard to new second-generation tyrosine kinase inhibitors.

  19. Creative destruction and export patterns

    DEFF Research Database (Denmark)

    Hansen, Jørgen Drud; Kvedaras, Virmantas; Nielsen, Jørgen Ulff-Møller

    2014-01-01

    varieties obsolete. For a given technology (variety) production costs decrease after an infant period due to learning. While all firms are assumed to be symmetric in a life-cycle perspective, at a given point in time firms of different ages differ in productivity, firm size, product quality, and export...... behavior. The model highlights a process of creative destruction, which allows firms to produce in a finite span of periods determined by the intensity of product and process innovations. The model predicts a wide range of export behavior of the individual firm during its life cycle depending...

  20. Quantitative investigation of the edge enhancement in in-line phase contrast projections and tomosynthesis provided by distributing microbubbles on the interface between two tissues: a phantom study

    Science.gov (United States)

    Wu, Di; Donovan Wong, Molly; Li, Yuhua; Fajardo, Laurie; Zheng, Bin; Wu, Xizeng; Liu, Hong

    2017-12-01

    The objective of this study was to quantitatively investigate the ability to distribute microbubbles along the interface between two tissues, in an effort to improve the edge and/or boundary features in phase contrast imaging. The experiments were conducted by employing a custom designed tissue simulating phantom, which also simulated a clinical condition where the ligand-targeted microbubbles are self-aggregated on the endothelium of blood vessels surrounding malignant cells. Four different concentrations of microbubble suspensions were injected into the phantom: 0%, 0.1%, 0.2%, and 0.4%. A time delay of 5 min was implemented before image acquisition to allow the microbubbles to become distributed at the interface between the acrylic and the cavity simulating a blood vessel segment. For comparison purposes, images were acquired using three system configurations for both projection and tomosynthesis imaging with a fixed radiation dose delivery: conventional low-energy contact mode, low-energy in-line phase contrast and high-energy in-line phase contrast. The resultant images illustrate the edge feature enhancements in the in-line phase contrast imaging mode when the microbubble concentration is extremely low. The quantitative edge-enhancement-to-noise ratio calculations not only agree with the direct image observations, but also indicate that the edge feature enhancement can be improved by increasing the microbubble concentration. In addition, high-energy in-line phase contrast imaging provided better performance in detecting low-concentration microbubble distributions.

  1. Destructive spondyloarthropathy in hemodialysis patients

    International Nuclear Information System (INIS)

    Orzincolo, C.; Ghedini, M.; Cardona, P.; Bedani, P.L.; Scutellari, P. N.

    1991-01-01

    Destructive spondyloarthropathy (DSA) has been observed in patients undergoing long-term hemodialysis. The pathophysiology of this condition is still unknown, but there is evidence that amyloid depositions play an important role in its development. Despite several reports, the radiological evolution of these lesions is poorly known. The authors report the results of the radiographic follow-up (12-18 months) of 9 cases (7 female and 2 male patients; age 63±6 years) hemodilized for over 60 months (mean: 126±33). In 7 cases. radiographic patterns of destructive arthropathy were seen in peripheral joints as well. X-ray pictures demonstrated: 1) increased erosion of vertebral end plates (in all cases); 2) increased narrowing of invertebral spaces (in 5 cases); 3) increased collapse of vertebral bodies (in 5 cases); 4) increased malalignment of the involved segments (in 4 cases). In 3 autopsied cases β 2 -microglobulin amyloid depositions were found in disc and ligamentous paravertebral tissue. These results confirm that: 1) DSA is progressive in longterm hemodialysis patients; 2) radiographic evolution is often very quick; 3) the cervical spine is the most frequently involved location and the one where lesions are quickest to develop; 4) severe malalignament of the involved spine may be present, with subsequent neurological complications

  2. Evaluation of nitrate destruction methods

    International Nuclear Information System (INIS)

    Taylor, P.A.; Kurath, D.E.; Guenther, R.

    1993-01-01

    A wide variety of high nitrate-concentration aqueous mixed [radioactive and Resource Conservation and Recovery Act (RCRA) hazardous] wastes are stored at various US Department of Energy (DOE) facilities. These wastes will ultimately be solidified for final disposal, although the waste acceptance criteria for the final waste form is still being determined. Because the nitrates in the wastes will normally increase the volume or reduce the integrity of all of the waste forms under consideration for final disposal, nitrate destruction before solidification of the waste will generally be beneficial. This report describes and evaluates various technologies that could be used to destroy the nitrates in the stored wastes. This work was funded by the Department of Energy's Office of Technology Development, through the Chemical/Physical Technology Support Group of the Mixed Waste Integrated Program. All the nitrate destruction technologies will require further development work before a facility could be designed and built to treat the majority of the stored wastes. Several of the technologies have particularly attractive features: the nitrate to ammonia and ceramic (NAC) process produces an insoluble waste form with a significant volume reduction, electrochemical reduction destroys nitrates without any chemical addition, and the hydrothermal process can simultaneously treat nitrates and organics in both acidic and alkaline wastes. These three technologies have been tested using lab-scale equipment and surrogate solutions. At their current state of development, it is not possible to predict which process will be the most beneficial for a particular waste stream

  3. Self-Destructing Dark Matter

    Energy Technology Data Exchange (ETDEWEB)

    Grossman, Yuval [Cornell U., LEPP; Harnik, Roni [Fermilab; Telem, Ofri [Cornell U., LEPP; Zhang, Yue [Northwestern U.

    2017-12-01

    We present Self-Destructing Dark Matter (SDDM), a new class of dark matter models which are detectable in large neutrino detectors. In this class of models, a component of dark matter can transition from a long-lived state to a short-lived one by scattering off of a nucleus or an electron in the Earth. The short-lived state then decays to Standard Model particles, generating a dark matter signal with a visible energy of order the dark matter mass rather than just its recoil. This leads to striking signals in large detectors with high energy thresholds. We present a few examples of models which exhibit self destruction, all inspired by bound state dynamics in the Standard Model. The models under consideration exhibit a rich phenomenology, possibly featuring events with one, two, or even three lepton pairs, each with a fixed invariant mass and a fixed energy, as well as non-trivial directional distributions. This motivates dedicated searches for dark matter in large underground detectors such as Super-K, Borexino, SNO+, and DUNE.

  4. Targeting property and toxicity of a novel ultrasound contrast agent microbubble carrying the targeting and drug-loaded complex FA-CNTs-PTX on MCF7 cells.

    Science.gov (United States)

    Zhang, Jie; Zhang, Yu; Liu, Junxi; Li, Guozhong; Wen, Zhaohui; Zhao, Yue; Zhang, Xiangyu; Liu, Fenghua

    2017-10-01

    The application of ultrasound contrast agents not only is confined to the enhancement of ultrasound imaging but also has started to be used as a drug system for diagnosis and treatment. In this paper, Span60 and PEG1500 were used as membrane materials, and a new targeting and drug-loading multifunctional ultrasound contrast agent microbubble enveloping the FA-CNTs-PTX complex was successfully prepared by acoustic cavitation. With the breast cancer cell line MCF7 as the research target, the effects of the microbubble with FA-CNTs-PTX on the proliferation and toxicity of MCF7 cells were studied using a CCK-8 and AO/EB double-staining method. The influences of the microbubbles with FA-CNTs-PTX on the cellular morphology and apoptosis period of the MCF7 cells were detected using an inverted fluorescence microscope. The apoptosis of MCF7 cells induced by the microbubbles with FA-CNTs-PTX was investigated with flow cytometry and an annexin and PI double staining fluorescence quantitative analysis. The results indicated that the ultrasound contrast agent microbubble with FA-CNTs-PTX remarkably inhibited the proliferation of MCF7 cells, which was mainly controlled by the drug loading rate and the nanometer size of the microbubbles. Moreover, the proliferative inhibition rate of the microbubbles with FA-CNTs-PTX was related to the cell apoptosis period of MCF7 cells. Its inhibition degree on the proliferation of MCF7 cells was higher than that of the hepatoma HepG2 cells. The apoptosis rate of MCF7 cells induced by the microbubbles with FA-CNTs-PTX was higher than that of normal human umbilical vein endothelial cells (HUVECs), and the microbubbles with FA-CNTs-PTX could target the MCF7 cells. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Mechanism of Microbubble Growth at Mitral Mechanical Heart Valve (MHV) Closure

    Science.gov (United States)

    Rambod, Edmond; Beizaie, Masoud; Shusser, Michael; Gharib, Morteza

    1999-11-01

    The growth mechanism of microbubbles at mitral MHV closure has been experimentally studied. In the heart, some of the tiny bubbles grow explosively and form larger and persistent bubbles. An experimental set-up was designed to allow the passage of micron-size bubbles through an 80 micron-wide slot, simulating a typical gap between the housing ring and the occluders in MHV. The bubbles were generated using an air-liquid dispenser and were delivered to the system via a 250 micron-diameter hypedermic needle positioned vertically near the slot. A solenoid valve was used to deliver a 10cc volume of liquid in 25ms time through the slot. High-speed imaging was used to study the impact of flow through the slot on bubble growth. The velocity of liquid through the slot was assessed to be in the range of 12-15 m/s. Our observations confirmed the rapid and drastic growth of microbubbles following their passage through the narrow slot, due to pressure drop. Vortices, which were induced by flow separation on the downstream of the slot, caused the grown bubbles to shatter and form more stable bubbles.

  6. Acoustic scattering from a contrast agent microbubble near an elastic wall of finite thickness

    International Nuclear Information System (INIS)

    Doinikov, Alexander A; Aired, Leila; Bouakaz, Ayache

    2011-01-01

    Interest in the problem under consideration in this study is motivated by targeted ultrasound imaging where one has to deal with microbubble contrast agents pulsating near blood vessel walls. A modified Rayleigh–Plesset equation is derived that describes the oscillation of a contrast agent microbubble near an elastic wall of finite thickness. It is assumed that the medium behind the wall is a fluid but it is shown that the equation obtained is easily transformable to the case that the medium behind the wall is an elastic solid. In contrast to the model of a rigid wall, which predicts decreasing natural frequency of a bubble near the wall, the elastic wall model reveals that the bubble natural frequency can both decrease and increase, and in cases of interest for medical applications, the bubble natural frequency usually increases. It is found that the influence of an elastic wall on the acoustic response of a bubble is determined by the ratio between a cumulative parameter, which integrally characterizes the mechanical properties of the wall and has the dimension of density, and the density of the liquid surrounding the bubble. It is shown that the acoustic influence of the arterial wall on the bubble is weak and apparently cannot be used to recognize the moment when the bubble approaches the wall. However, in experiments where the behavior of bubbles near various plastic walls is observed, changes in the bubble response, such as increasing natural frequency and decreasing oscillation amplitude, are detectable.

  7. Toward automated selective retina treatment (SRT): an optical microbubble detection technique

    Science.gov (United States)

    Seifert, Eric; Park, Young-Gun; Theisen-Kunde, Dirk; Roh, Young-Jung; Brinkmann, Ralf

    2018-02-01

    Selective retina therapy (SRT) is an ophthalmological laser technique, targeting the retinal pigment epithelium (RPE) with repetitive microsecond laser pulses, while causing no thermal damage to the neural retina, the photoreceptors as well as the choroid. The RPE cells get damaged mechanically by microbubbles originating, at the intracellular melanosomes. Beneficial effects of SRT on Central Serous Retinopathy (CSR) and Diabetic Macula Edema (DME) have already been shown. Variations in the transmission of the anterior eye media and pigmentation variation of RPE yield in intra- and inter- individual thresholds of the pulse energy required for selective RPE damage. Those selective RPE lesions are not visible. Thus, dosimetry-systems, designed to detect microbubbles as an indicator for RPE cell damage, are demanded elements to facilitate SRT application. Therefore, a technique based on the evaluation of backscattered treatment light has been developed. Data of 127 spots, acquired during 10 clinical treatments of CSR patients, were assigned to a RPE cell damage class, validated by fluorescence angiography (FLA). An algorithm has been designed to match the FLA based information. A sensitivity of 0.9 with a specificity close to 1 is achieved. The data can be processed within microseconds. Thus, the process can be implemented in existing SRT lasers with an automatic pulse wise increasing energy and an automatic irradiation ceasing ability to enable automated treatment close above threshold to prevent adverse effects caused by too high pulse energy. Alternatively, a guidance procedure, informing the treating clinician about the adequacy of the actual settings, is possible.

  8. Nonlinear oscillation and interfacial stability of an encapsulated microbubble under dual-frequency ultrasound

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yunqiao [MOE Key Laboratory of Hydrodynamics, Department of Engineering Mechanics, Shanghai Jiao Tong University, Shanghai 200240 (China); Calvisi, Michael L [Department of Mechanical and Aerospace Engineering, University of Colorado, Colorado Springs, CO 80918, United States of America (United States); Wang, Qianxi, E-mail: yunqiaoliu@sjtu.edu.cn [School of Mathematics, University of Birmingham, Birmingham B15 2TT (United Kingdom)

    2017-04-15

    Encapsulated microbubbles (EMBs) are widely used in medical ultrasound imaging as contrast-enhanced agents. However, the potential damaging effects of violent collapsing EMBs to cells and tissues in clinical settings have remained a concern. Dual-frequency ultrasound is a promising technique for improving the efficacy and safety of sonography. The system modeled consists of the external liquid, membrane and internal gases of an EMB. The microbubble dynamics are simulated using a simple nonlinear interactive theory, considering the compressibility of the internal gas, viscosity of the liquid flow and viscoelasticity of the membrane. The radial oscillation and interfacial stability of an EMB under single- and dual-frequency excitations are compared. The simulation results show that the dual-frequency technique produces larger backscatter pressure at higher harmonics of the primary driving frequency—this enriched acoustic spectrum can enhance blood-tissue contrast and improve the quality of sonographic images. The results further show that the acoustic pressure threshold associated with the onset of shape instability is greater for dual-frequency driving. This suggests that the dual-frequency technique stabilizes the encapsulated bubble, thereby improving the efficacy and safety of contrast-enhanced agents. (paper)

  9. Investigation on the relationship between overpressure and sub-harmonic response from encapsulated microbubbles

    International Nuclear Information System (INIS)

    Wu Jun; Xu Di; Fan Ting-Bo; Zhang Dong

    2014-01-01

    Sub-harmonic component generated from microbubbles is proven to be potentially used in noninvasive blood pressure measurement. Both theoretical and experimental studies are performed in the present work to investigate the dependence of the sub-harmonic generation on the overpressure with different excitation pressure amplitudes and pulse lengths. With 4-MHz ultrasound excitation at an applied acoustic pressure amplitude of 0.24 MPa, the measured sub-harmonic amplitude exhibits a decreasing change as overpressure increases; while non-monotonic change is observed for the applied acoustic pressures of 0.36 MPa and 0.48 MPa, and the peak position in the curve of the sub-harmonic response versus the overpressure shifts toward higher overpressure as the excitation pressure amplitude increases. Furthermore, the exciting pulse with long duration could lead to a better sensitivity of the sub-harmonic response to overpressure. The measured results are explained by the numerical simulations based on the Marmottant model. The numerical simulations qualitatively accord with the measured results. This work might provide a preliminary proof for the optimization of the noninvasive blood pressure measurement through using sub-harmonic generation from microbubbles. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  10. Investigation on the relationship between overpressure and sub-harmonic response from encapsulated microbubbles

    Science.gov (United States)

    Wu, Jun; Fan, Ting-Bo; Xu, Di; Zhang, Dong

    2014-10-01

    Sub-harmonic component generated from microbubbles is proven to be potentially used in noninvasive blood pressure measurement. Both theoretical and experimental studies are performed in the present work to investigate the dependence of the sub-harmonic generation on the overpressure with different excitation pressure amplitudes and pulse lengths. With 4-MHz ultrasound excitation at an applied acoustic pressure amplitude of 0.24 MPa, the measured sub-harmonic amplitude exhibits a decreasing change as overpressure increases; while non-monotonic change is observed for the applied acoustic pressures of 0.36 MPa and 0.48 MPa, and the peak position in the curve of the sub-harmonic response versus the overpressure shifts toward higher overpressure as the excitation pressure amplitude increases. Furthermore, the exciting pulse with long duration could lead to a better sensitivity of the sub-harmonic response to overpressure. The measured results are explained by the numerical simulations based on the Marmottant model. The numerical simulations qualitatively accord with the measured results. This work might provide a preliminary proof for the optimization of the noninvasive blood pressure measurement through using sub-harmonic generation from microbubbles.

  11. Enhanced cell killing and apoptosis of oral squamous cell carcinoma cells with ultrasound in combination with cetuximab coated albumin microbubbles.

    Science.gov (United States)

    Narihira, Kyoichi; Watanabe, Akiko; Sheng, Hong; Endo, Hitomi; Feril, Loreto B; Irie, Yutaka; Ogawa, Koichi; Moosavi-Nejad, Seyedeh; Kondo, Seiji; Kikuta, Toshihiro; Tachibana, Katsuro

    2018-03-01

    Targeted microbubbles have the potential to be used for ultrasound (US) therapy and diagnosis of various cancers. In the present study, US was irradiated to oral squamous cell carcinoma cells (HSC-2) in the presence of cetuximab-coated albumin microbubbles (CCAM). Cell killing rate with US treatment at 0.9 W/cm 2 and 1.0 W/cm 2 in the presence of CCAM was greater compared to non-targeted albumin microbubbles (p < .05). On the other hand, selective cell killing was not observed in human myelomonocytic lymphoma cell line (U937) that had no affinity to cetuximab. Furthermore, US irradiation in the presence of CCAM showed a fivefold increase of cell apoptotic rate for HSC-2 cells (21.0 ± 3.8%) as compared to U937 cells (4.0 ± 0.8%). Time-signal intensity curve in a tissue phantom demonstrated clear visualisation of CCAM with conventional US imaging device. Our experiment verifies the hypothesis that CCAM was selective to HSC-2 cells and may be applied as a novel therapeutic/diagnostic microbubble for oral squamous cell carcinoma.

  12. Indirect Self-Destructiveness and Emotional Intelligence.

    Science.gov (United States)

    Tsirigotis, Konstantinos

    2016-06-01

    While emotional intelligence may have a favourable influence on the life and psychological and social functioning of the individual, indirect self-destructiveness exerts a rather negative influence. The aim of this study has been to explore possible relations between indirect self-destructiveness and emotional intelligence. A population of 260 individuals (130 females and 130 males) aged 20-30 (mean age of 24.5) was studied by using the Polish version of the chronic self-destructiveness scale and INTE, i.e., the Polish version of the assessing emotions scale. Indirect self-destructiveness has significant correlations with all variables of INTE (overall score, factor I, factor II), and these correlations are negative. The intensity of indirect self-destructiveness differentiates significantly the height of the emotional intelligence and vice versa: the height of the emotional intelligence differentiates significantly the intensity of indirect self-destructiveness. Indirect self-destructiveness has negative correlations with emotional intelligence as well as its components: the ability to recognize emotions and the ability to utilize emotions. The height of emotional intelligence differentiates the intensity of indirect self-destructiveness, and vice versa: the intensity of indirect self-destructiveness differentiates the height of emotional intelligence. It seems advisable to use emotional intelligence in the prophylactic and therapeutic work with persons with various types of disorders, especially with the syndrome of indirect self-destructiveness.

  13. Microbubble Enzyme-Linked Immunosorbent Assay for the Detection of Targeted Microbubbles in in Vitro Static Binding Assays.

    Science.gov (United States)

    Wischhusen, Jennifer; Padilla, Frederic

    2017-07-01

    Targeted microbubbles (MBs) are ultrasound contrast agents that are functionalized with a ligand for ultrasound molecular imaging of endothelial markers. Novel targeted MBs are characterized in vitro by incubation in protein-coated wells, followed by binding quantification by microscopy or ultrasound imaging. Both methods provide operator-dependent results: Between 3 and 20 fields of view from a heterogeneous sample are typically selected for analysis by microscopy, and in ultrasound imaging, different acoustic settings affect signal intensities. This study proposes a new method to reproducibly quantify MB binding based on enzyme-linked immunosorbent assay (ELISA), in which bound MBs are revealed with an enzyme-linked antibody. MB-ELISA was adapted to in vitro static binding assays, incubating the MBs in inverted position or by agitation, and compared with microscopy. The specificity and sensitivity of MB-ELISA enable the reliable quantification of MB binding in a rapid, high-throughput and whole-well analysis, facilitating the characterization of new targeted contrast agents. Copyright © 2017 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  14. 9 CFR 51.6 - Destruction of animals; time limit for destruction of animals.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Destruction of animals; time limit for destruction of animals. 51.6 Section 51.6 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION... ANIMALS DESTROYED BECAUSE OF BRUCELLOSIS Indemnity for Cattle, Bison, and Swine § 51.6 Destruction of...

  15. Weapons of mass destruction, WMD

    International Nuclear Information System (INIS)

    Vogel, H.

    2007-01-01

    Purpose: Since the invasion into Iraq in 2003, weapons of mass destruction (WMD), have come to general notice; they include today chemical, biological, and atomic/nuclear weapons, (CW, BW, and AW). Radiological findings shall be described. Material and methods: X-ray findings of victims of WMD are described. From CW, own observations are reported. Examples of (possible) X-ray findings of victims of BW are described. AW may induce radiation disease. Results: Exposure to sulfur-lost induces severe bronchitis; if the radiograph shows pulmonary infiltrations, the prognosis is bad; a late consequence maybe bronchiectasis. BW can be based on bacteria, virus or toxins. An approach of the X-ray findings for BW victims is based on the assumption that the disease induced by BW has the same (or a similar) clinic and radiology as that induced by the original microorganism or by the unchanged toxism. This approximation may have its limits, if the germ or toxin has been modified. In survivors of AW, the radiology is probably that of victims of thermal radiation and blast. Conclusion: WMD seem to be a real or a possible threat. They can be used in war, in terrorist attacks, in crime, and in action of secret services. In case that WMD are employed, X-ray diagnostic will be used to evaluate the prognosis (triage) and the risk of infection

  16. Weapons of mass destruction, WMD

    Energy Technology Data Exchange (ETDEWEB)

    Vogel, H. [Asklepios Klinik St. Georg, Roentgenabteilung, Lohmuehlenstrasse 5, D-20099 Hamburg (Germany)], E-mail: Hermann.vogel@ak-stgeorg.lbk-hh.de

    2007-08-15

    Purpose: Since the invasion into Iraq in 2003, weapons of mass destruction (WMD), have come to general notice; they include today chemical, biological, and atomic/nuclear weapons, (CW, BW, and AW). Radiological findings shall be described. Material and methods: X-ray findings of victims of WMD are described. From CW, own observations are reported. Examples of (possible) X-ray findings of victims of BW are described. AW may induce radiation disease. Results: Exposure to sulfur-lost induces severe bronchitis; if the radiograph shows pulmonary infiltrations, the prognosis is bad; a late consequence maybe bronchiectasis. BW can be based on bacteria, virus or toxins. An approach of the X-ray findings for BW victims is based on the assumption that the disease induced by BW has the same (or a similar) clinic and radiology as that induced by the original microorganism or by the unchanged toxism. This approximation may have its limits, if the germ or toxin has been modified. In survivors of AW, the radiology is probably that of victims of thermal radiation and blast. Conclusion: WMD seem to be a real or a possible threat. They can be used in war, in terrorist attacks, in crime, and in action of secret services. In case that WMD are employed, X-ray diagnostic will be used to evaluate the prognosis (triage) and the risk of infection.

  17. Non-destructive testing at Chalk River

    International Nuclear Information System (INIS)

    Hilborn, J.W.

    1976-01-01

    In 1969 CRNL recognized the need for a strong group skilled in non-destructive test procedures. Within two years a new branch called Quality Control Branch was staffed and working. This branch engages in all aspects of non-destructive testing including development of new techniques, new applications of known technology, and special problems in support of operating reactors. (author)

  18. Noninvasive, localized, and transient brain drug delivery using focused ultrasound and microbubbles

    Science.gov (United States)

    Choi, James J.

    In the United States, Alzheimer's disease (AD), Parkinson's disease (PD), and brain cancer caused 72,432, 19,566 and 12,886 deaths in 2006, respectively. Whereas the number of deaths due to major disorders such as heart disease, stroke, and prostate cancer have decreased since 2006, deaths attributed to AD, PD, and brain cancer have not. Treatment options for patients with CNS disorders remain limited despite significant advances in knowledge of CNS disease pathways and development of neurologically potent agents. One of the major obstacles is that the cerebral microvasculature is lined by a specialized and highly regulated blood-brain barrier (BBB) that prevents large agents from entering the brain extracellular space. The purpose of this dissertation is to design a noninvasive, localized, and transient BBB opening system using focused ultrasound (FUS) and determine ultrasound and microbubble conditions that can effectively and safely deliver large pharmacologically-relevant-sized agents to the brain. To meet this end, an in vivo mouse brain drug delivery system using a stereotactic-based targeting method was developed. FUS was applied noninvasively through the intact skin and skull, which allowed for long-term and high-throughput studies. With this system, more than 150 mice were exposed to one of 31 distinct acoustic and microbubble conditions. The feasibility of delivering a large MRI contrast agent was first demonstrated in vivo in both wild-type and transgenic Alzheimer's disease model (APP/PS1) mice. A wide range of acoustic and microbubble conditions were then evaluated for their ability to deliver agents to a target region. Interestingly, the possible design space of parameters was found to be vast and different conditions resulted in distinct spatial distributions and doses delivered. In particular, BBB opening was shown to be dependent on the microbubble diameter, acoustic pressure, pulse repetition frequency (PRF), and pulse length (PL). Each set of

  19. Generation of emulsion droplets and micro-bubbles in microfluidic devices

    KAUST Repository

    Zhang, Jiaming

    2016-04-01

    Droplet-based microfluidic devices have become a preferred versatile platform for various fields in physics, chemistry and biology to manipulate small amounts of liquid samples. In addition to microdroplets, microbubbles are also needed for various pro- cesses in the food, healthcare and cosmetic industries. Polydimethylsiloxane (PDMS) soft lithography, the mainstay for fabricating microfluidic devices, usually requires the usage of expensive apparatus and a complex manufacturing procedure. In ad- dition, current methods have the limited capabilities for fabrication of microfluidic devices within three dimensional (3D) structures. Novel methods for fabrication of droplet-based microfluidic devices for the generation microdroplets and microbubbles are therefore of great interest in current research. In this thesis, we have developed several simple, rapid and low-cost methods for fabrication of microfluidic devices, especially for generation of microdroplets and mi- crobubbles. We first report an inexpensive full-glass microfluidic devices with as- sembly of glass capillaries, for generating monodisperse multiple emulsions. Different types of devices have been designed and tested and the experimental results demon- strated the robust capability of preparing monodisperse single, double, triple and multi-component emulsions. Second, we propose a similar full-glass device for generation of microbubbles, but with assembly of a much smaller nozzle of a glass capillary. Highly monodisperse microbubbles with diameter range from 3.5 to 60 microns have been successfully produced, at rates up to 40 kHz. A simple scaling law based on the capillary number and liquid-to-gas flow rate ratio, successfully predicts the bubble size. Recently, the emergent 3D printing technology provides an attractive fabrication technique, due to its simplicity and low cost. A handful of studies have already demonstrated droplet production through 3D-printed microfluidic devices. However, two

  20. Scalable and reusable micro-bubble removal method to flatten large-area 2D materials

    Science.gov (United States)

    Pham, Phi H. Q.; Quach, Nhi V.; Li, Jinfeng; Burke, Peter J.

    2018-04-01

    Bubbles generated during electro-delamination and chemical etch during large-area two-dimensional (2D) material transfer has been shown to cause rippling, and consequently, results in tears and wrinkles in the transferred film. Here, we demonstrate a scalable and reusable method to remove surface adhered micro-bubbles by using hydrophobic surfaces modified by self-assembled monolayers (SAMs). Bubble removal allows the 2D film to flatten out and prevents the formation of defects. Electrical characterization was used to verify improved transfer quality and was confirmed by increased field-effect mobility and decreased sheet resistance. Raman spectroscopy was also used to validate enhanced electrical quality following transfer. The bubble removal method can be applied to an assortment of 2D materials using diverse hydrophobic SAM variants. Our studies can be integrated into large scale applications and will lead to improved large-area 2D electronics in general.

  1. Porous Polymeric Films from Microbubbles Generated Using a T-Junction Microfluidic Device.

    Science.gov (United States)

    Elsayed, M; Kothandaraman, A; Edirisinghe, M; Huang, J

    2016-12-20

    In this work, a simple microfluidic junction with a T geometry and coarse (200 μm diameter) capillaries was used to generate monodisperse microbubbles with an alginate polymer shell. Subsequently, these bubbles were used to prepare porous alginate films with good control over the pore structure. The lack of pore size, shape, and surface control in scalable forming of polymeric films is a major application-limiting drawback at present. Controlling the thinning process of the shell of the bubbles to tune the surface of the resulting structures was also explored. Films were prepared with nanopatterned surfaces by controlling the thinning of the bubble shell, with the aid of surfactants, to induce efficient bursting (fragmentation) of bubbles to generate nanodroplets, which become embedded within the film surface. This novel feature greatly expands and enhances the use of hydrophilic polymers in a wide range of biomedical applications, particularly in drug delivery and tissue engineering, such as studying cellular responses to different morphological surfaces.

  2. A model for an acoustically driven microbubble inside a rigid tube

    KAUST Repository

    Qamar, Adnan

    2014-09-10

    A theoretical framework to model the dynamics of acoustically driven microbubble inside a rigid tube is presented. The proposed model is not a variant of the conventional Rayleigh-Plesset category of models. It is derived from the reduced Navier-Stokes equation and is coupled with the evolving flow field solution inside the tube by a similarity transformation approach. The results are computed, and compared with experiments available in literature, for the initial bubble radius of Ro=1.5μm and 2μm for the tube diameter of D=12μm and 200μm with the acoustic parameters as utilized in the experiments. Results compare quite well with the existing experimental data. When compared to our earlier basic model, better agreement on a larger tube diameter is obtained with the proposed coupled model. The model also predicts, accurately, bubble fragmentation in terms of acoustic and geometric parameters.

  3. Nonlinear response of ultrasound contrast agent microbubbles: From fundamentals to applications

    International Nuclear Information System (INIS)

    Teng Xu-Dong; Guo Xia-Sheng; Tu Juan; Zhang Dong

    2016-01-01

    Modelling and biomedical applications of ultrasound contrast agent (UCA) microbubbles have attracted a great deal of attention. In this review, we summarize a series of researches done in our group, including (i) the development of an all-in-one solution of characterizing coated bubble parameters based on the light scattering technique and flow cytometry; (ii) a novel bubble dynamic model that takes into consideration both nonlinear shell elasticity and viscosity to eliminate the dependences of bubble shell parameters on bubble size; (iii) the evaluation of UCA inertial cavitation threshold and its relationship with shell parameters; and (iv) the investigations of transfection efficiency and the reduction of cytotoxicity in gene delivery facilitated by UCAs excited by ultrasound exposures. (special topic)

  4. Collisional destruction of fast hydrogen Rydberg atoms

    International Nuclear Information System (INIS)

    King, M.R.

    1984-01-01

    A new modulated electric field technique was developed to study Rydberg atom destruction processes in a fast beam. The process of destruction of a band of Rydberg atom destruction of a band of Rydberg atoms through the combined processes of ionization, excitation, and deexcitation was studied for collisions with gas targets. Rydberg atoms of hydrogen were formed by electron capture, and detected by field ionization. The modulated field technique described proved to be an effective technique for producing a large signal for accurate cross section measurements. The independent particle model for Rydberg atom destruction processes was found to hold well for collisions with molecular nitrogen, argon, and carbon dioxide. The resonances in the cross sections for the free electron scattering with these targets were found to also occur in Rydberg destruction. Suggestions for future investigations of Rydberg atom collision processes in the fast beam regime are given

  5. Ultrasonographic detection of focal liver lesions: increased sensitivity and specificity with microbubble contrast agents

    International Nuclear Information System (INIS)

    Hohmann, J.; Albrecht, T.; Hoffmann, C.W.; Wolf, K.-J.

    2003-01-01

    Ultrasonography (US) is the first choice for screening patients with suspected liver lesions. However, due to a lack of contrast agents, US used to be less sensitive and specific compared with computed tomography (CT) and magnet resonance imaging (MRI). The advent of microbubble contrast agents increased both sensitivity and specificity dramatically. Rapid developments of the contrast agents as well as of special imaging techniques were made in recent years. Today numerous different US imaging methods exist which based either on Doppler or on harmonic imaging. They are using the particular behaviour of microbubbles in a sound field which varies depending on the energy of insonation (low/high mechanical index, MI) as well as on the properties of the agent themselves. Apart from just blood pool enhancement some agents have a hepatosplenic specific late phase. US imaging during this late phase using relatively high MI in phase inversion mode (harmonic imaging) or stimulated acoustic emission (SAE; Doppler method) markedly improves the detection of focal liver lesions and is also very helpful for lesion characterisation. With regards to detection, contrast enhanced US performs similarly to CT as shown by recent studies. Early results of studies using low MI imaging and the newer perfluor agents are also showing promising results for lesion detection. Low MI imaging with these agents has the advantage of real time imaging and is particularly helpful for characterisation of focal lesions based on their dynamic contrast behaviour. Apart from the techniques which based on the morphology of liver lesions there were some attempts for the detection of occult metastases or micrometastases by means of liver blood flow changes. Also in this field the use of US contrast agents appears to have advantages over formerly used non contrast-enhanced methods although no conclusive results are available yet

  6. Longitudinal relations between constructive and destructive conflict and couples' sleep.

    Science.gov (United States)

    El-Sheikh, Mona; Kelly, Ryan J; Koss, Kalsea J; Rauer, Amy J

    2015-06-01

    We examined longitudinal relations between interpartner constructive (negotiation) and destructive (psychological and physical aggression) conflict strategies and couples' sleep over 1 year. Toward explicating processes of effects, we assessed the intervening role of internalizing symptoms in associations between conflict tactics and couples' sleep. Participants were 135 cohabiting couples (M age = 37 years for women and 39 years for men). The sample included a large representation of couples exposed to economic adversity. Further, 68% were European American and the remainder were primarily African American. At Time 1 (T1), couples reported on their conflict and their mental health (depression, anxiety). At T1 and Time 2, sleep was examined objectively with actigraphs for 7 nights. Three sleep parameters were derived: efficiency, minutes, and latency. Actor-partner interdependence models indicated that husbands' use of constructive conflict forecasted increases in their own sleep efficiency as well as their own and their wives' sleep duration over time. Actor and partner effects emerged, and husbands' and wives' use of destructive conflict strategies generally predicted worsening of some sleep parameters over time. Several mediation and intervening effects were observed for destructive conflict strategies. Some of these relations reveal that destructive conflict is associated with internalizing symptoms, which in turn are associated with some sleep parameters longitudinally. These findings build on a small, albeit growing, literature linking sleep with marital functioning, and illustrate that consideration of relationship processes including constructive conflict holds promise for gaining a better understanding of factors that influence the sleep of men and women. (c) 2015 APA, all rights reserved).

  7. The impact of vaporized nanoemulsions on ultrasound-mediated ablation.

    Science.gov (United States)

    Zhang, Peng; Kopechek, Jonathan A; Porter, Tyrone M

    2013-01-01

    The clinical feasibility of using high-intensity focused ultrasound (HIFU) for ablation of solid tumors is limited by the high acoustic pressures and long treatment times required. The presence of microbubbles during sonication can increase the absorption of acoustic energy and accelerate heating. However, formation of microbubbles within the tumor tissue remains a challenge. Phase-shift nanoemulsions (PSNE) have been developed as a means for producing microbubbles within tumors. PSNE are emulsions of submicron-sized, lipid-coated, and liquid perfluorocarbon droplets that can be vaporized into microbubbles using short (5 MPa) acoustic pulses. In this study, the impact of vaporized phase-shift nanoemulsions on the time and acoustic power required for HIFU-mediated thermal lesion formation was investigated in vitro. PSNE containing dodecafluoropentane were produced with narrow size distributions and mean diameters below 200 nm using a combination of sonication and extrusion. PSNE was dispersed in albumin-containing polyacrylamide gel phantoms for experimental tests. Albumin denatures and becomes opaque at temperatures above 58°C, enabling visual detection of lesions formed from denatured albumin. PSNE were vaporized using a 30-cycle, 3.2-MHz, at an acoustic power of 6.4 W (free-field intensity of 4,586 W/cm(2)) pulse from a single-element, focused high-power transducer. The vaporization pulse was immediately followed by a 15-s continuous wave, 3.2-MHz signal to induce ultrasound-mediated heating. Control experiments were conducted using an identical procedure without the vaporization pulse. Lesion formation was detected by acquiring video frames during sonication and post-processing the images for analysis. Broadband emissions from inertial cavitation (IC) were passively detected with a focused, 2-MHz transducer. Temperature measurements were acquired using a needle thermocouple. Bubbles formed at the HIFU focus via PSNE vaporization enhanced HIFU-mediated heating

  8. Can non-destructive inspection be reliable

    International Nuclear Information System (INIS)

    Silk, M.G.; Stoneham, A.M.; Temple, J.A.G.

    1988-01-01

    The paper on inspection is based on the book ''The reliability of non-destructive inspection: assessing the assessment of structures under stress'' by the present authors (published by Adam Hilger 1987). Emphasis is placed on the reliability of inspection and whether cracks in welds or flaws in components can be detected. The need for non-destructive testing and the historical attitudes to non-destructive testing are outlined, along with the case of failure. Factors influencing reliable inspection are discussed, and defect detection trials involving round robin tests are described. The development of reliable inspection techniques and the costs of reliability and unreliability are also examined. (U.K.)

  9. Disruption of tumor neovasculature by microbubble enhanced ultrasound: a potential new physical therapy of anti-angiogenesis.

    Science.gov (United States)

    Liu, Zheng; Gao, Shunji; Zhao, Yang; Li, Peijing; Liu, Jia; Li, Peng; Tan, Kaibin; Xie, Feng

    2012-02-01

    Tumor angiogenesis is of vital importance to the growth and metastasis of solid tumors. The angiogenesis is featured with a defective, leaky and fragile vascular construction. Microbubble enhanced ultrasound (MEUS) cavitation is capable of mechanical disruption of small blood vessels depending on effective acoustic pressure amplitude. We hypothesized that acoustic cavitation combining high-pressure amplitude pulsed ultrasound (US) and circulating microbubble could potentially disrupt tumor vasculature. A high-pressure amplitude, pulsed ultrasound device was developed to induce inertial cavitation of circulating microbubbles. The tumor vasculature of rat Walker 256 was insonated percutaneously with two acoustic pressures, 2.6 MPa and 4.8 MPa, both with intravenous injection of a lipid microbubble. The controls were treated by the ultrasound only or sham ultrasound exposure. Contrast enhanced ultrasound (CEUS) and histology were performed to assess tumor circulation and pathological changes. The CEUS results showed that the circulation of Walker 256 tumors could be completely blocked off for 24 hours in 4.8 MPa treated tumors. The CEUS gray scale value (GSV) indicated that there was significant GSV drop-off in both of the two experimental groups but none in the controls. Histology showed that the tumor microvasculature was disrupted into diffuse hematomas accompanied by thrombosis, intercellular edema and multiple cysts formation. The 24 hours of tumor circulation blockage resulted in massive necrosis of the tumor. MEUS provides a new, simple physical method for anti-angiogenic therapy and may have great potential for clinical applications. Copyright © 2012 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  10. Postradiation destruction of dextran in solutions

    International Nuclear Information System (INIS)

    Bondarenko, N.T.; Sharpatyj, V.A.

    1989-01-01

    Methods of pH-metry, UV absorption and ESR spectroscopy were used to study the oxidation destruction of dextran solutions, stored in the air after gamma irradiation ( 60 Co) bydoses of up to 200 kGy. It is shown that polymer destruction under mentioned conditions is initiated by hydroperoxide decomposition with successive radical transformation into peroxides. Experimentally observed periodical change of acidity of irradiated dextran solutions is also explained by transformations of peroxy radicals

  11. Ultrasound sonication with microbubbles disrupts blood vessels and enhances tumor treatments of anticancer nanodrug

    Directory of Open Access Journals (Sweden)

    Lin CY

    2012-04-01

    Full Text Available Chung-Yin Lin1*, Hsiao-Ching Tseng1*, Heng-Ruei Shiu1, Ming-Fang Wu2, Cheng-Ying Chou3, Win-Li Lin1,41Institute of Biomedical Engineering, 2Laboratory Animal Center, 3Department of Bio-Industrial Mechatronics Engineering, National Taiwan University, Taipei, Taiwan; 4Division of Medical Engineering Research, National Health Research Institutes, Miaoli, Taiwan*These authors contributed equally to this workAbstract: Ultrasound (US sonication with microbubbles (MBs has the potential to disrupt blood vessels and enhance the delivery of drugs into the sonicated tissues. In this study, mouse ear tumors were employed to investigate the therapeutic effects of US, MBs, and pegylated liposomal doxorubicin (PLD on tumors. Tumors started to receive treatments when they grew up to about 15 mm3 (early stage with injection of PLD 10 mg/kg, or up to 50 mm3 (medium stage with PLD 6 (or 4 mg/kg. Experiments included the control, PLD alone, PLD + MBs + US, US alone, and MBs + US groups. The procedure for the PLD + MBs + US group was that PLD was injected first, MB (SonoVue injection followed, and then US was immediately sonicated on the tumor. The results showed that: (1 US sonication with MBs was always able to produce a further hindrance to tumor growth for both early and medium-stage tumors; (2 for the medium-stage tumors, 6 mg/kg PLD alone was able to inhibit their growth, while it did not work for 4 mg/kg PLD alone; (3 with the application of MBs + US, 4 mg/kg PLD was able to inhibit the growth of medium-stage tumors; (4 for early stage tumors after the first treatment with a high dose of PLD alone (10 mg/kg, the tumor size still increased for several days and then decreased (a biphasic pattern; (5 MBs + US alone was able to hinder the growth of early stage tumors, but unable to hinder that of medium stage tumors. The results of histological examinations and blood perfusion measurements indicated that the application of MBs + US disrupts the tumor blood

  12. The Thrombolytic Effect of Diagnostic Ultrasound-Induced Microbubble Cavitation in Acute Carotid Thromboembolism.

    Science.gov (United States)

    Porter, Thomas R; Xie, Feng; Lof, John; Powers, Jeffry; Vignon, Francois; Shi, William; White, Matthew

    2017-08-01

    Acute ischemic stroke is often due to thromboembolism forming over ruptured atherosclerotic plaque in the carotid artery (CA). The presence of intraluminal CA thrombus is associated with a high risk of thromboembolic cerebral ischemic events. The cavitation induced by diagnostic ultrasound high mechanical index (MI) impulses applied locally during a commercially available intravenous microbubble infusion has dissolved intravascular thrombi, especially when using longer pulse durations. The beneficial effects of this in acute carotid thromboembolism is not known. An oversized balloon injury was created in the distal extracranial common CA of 38 porcine carotid arteries. After this, a 70% to 80% stenosis was created in the mid common CA proximal to the injury site using partial balloon inflation. Acute thrombotic CA occlusions were created just distal to the balloon catheter by injecting fresh autologous arterial thrombi. After angiographic documentation of occlusion, the common carotid thrombosis was treated with either diagnostic low MI imaging alone (0.2 MI; Philips S5-1) applied through a tissue mimicking phantom (TMP) or intermittent diagnostic high MI stable cavitation (SC)-inducing impulses with a longer pulse duration (0.8 MI; 20 microseconds' pulse duration) or inertial cavitation (IC) impulses (1.2 MI; 20 microseconds' pulse duration). All treatment times were for 30 minutes. Intravenous ultrasound contrast (2% Definity; Lantheus Medical) was infused during the treatment period. Angiographic recanalization in 4 intracranial and extracranial vessels downstream from the CA occlusion (auricular, ascending pharyngeal, buccinator, and maxillary) was assessed with both magnetic resonance 3-dimensional time-of-flight and phase contrast angiography. All magnetic resonance images were interpreted by an independent neuroradiologist using the thrombolysis in cerebral infarction (TICI) scoring system. By phase contrast angiography, at least mild recanalization (TICI 2a

  13. Synergistic enhancement of micro-bubble formation in ultrasound irradiated H2O-CH3OH mixtures probed by dynamic light scattering

    International Nuclear Information System (INIS)

    Pai, M.R.; Hassan, P.A.; Bharadwaj, S.R.; Kulshreshtha, S.K.

    2008-01-01

    This report investigates the formation of micro-bubbles in water-methanol mixtures upon ultrasound irradiation and its correlation with the yield of H 2 obtained as a result of sono-chemical splitting of water. The yield of hydrogen produced by sono-chemical reaction is monitored at different compositions of water-methanol mixtures. The evidence for the formation of micro-bubbles upon ultrasound irradiation is obtained by the dynamic light scattering technique. Micro-bubble formation during ultrasound irradiation of water-methanol mixtures, their stability and size distribution, has been quantitatively estimated. The effect of composition of the water-methanol mixture and duration of irradiation on the extent of bubble formation has been inferred from the changes in the light scattering intensity and its time correlation function. Exceptional stability of micro-bubbles without any additives is observed at a certain composition of the water-methanol mixture (4:3, v/v). The extent of micro-bubbles formed in the mixture correlates well with the yield of hydrogen detected. (authors)

  14. A high pulse repetition frequency ultrasound system for the ex vivo measurement of mechanical properties of crystalline lenses with laser-induced microbubbles interrogated by acoustic radiation force

    International Nuclear Information System (INIS)

    Yoon, Sangpil; Emelianov, Stanislav; Aglyamov, Salavat; Karpiouk, Andrei

    2012-01-01

    A high pulse repetition frequency ultrasound system for an ex vivo measurement of mechanical properties of an animal crystalline lens was developed and validated. We measured the bulk displacement of laser-induced microbubbles created at different positions within the lens using nanosecond laser pulses. An impulsive acoustic radiation force was applied to the microbubble, and spatio-temporal measurements of the microbubble displacement were assessed using a custom-made high pulse repetition frequency ultrasound system consisting of two 25 MHz focused ultrasound transducers. One of these transducers was used to emit a train of ultrasound pulses and another transducer was used to receive the ultrasound echoes reflected from the microbubble. The developed system was operating at 1 MHz pulse repetition frequency. Based on the measured motion of the microbubble, Young’s moduli of surrounding tissue were reconstructed and the values were compared with those measured using the indentation test. Measured values of Young’s moduli of four bovine lenses ranged from 2.6 ± 0.1 to 26 ± 1.4 kPa, and there was good agreement between the two methods. Therefore, our studies, utilizing the high pulse repetition frequency ultrasound system, suggest that the developed approach can be used to assess the mechanical properties of ex vivo crystalline lenses. Furthermore, the potential of the presented approach for in vivo measurements is discussed. (paper)

  15. Ultrasound-guided drug delivery in cancer

    Energy Technology Data Exchange (ETDEWEB)

    Chowdhury, Sayan Mullick; Lee, Tae Hwa; Willmann, Jugen K. [Dept. of Radiology, Stanford University School of Medicine, Stanford (United States)

    2017-07-15

    Recent advancements in ultrasound and microbubble (USMB) mediated drug delivery technology has shown that this approach can improve spatially confined delivery of drugs and genes to target tissues while reducing systemic dose and toxicity. The mechanism behind enhanced delivery of therapeutics is sonoporation, the formation of openings in the vasculature, induced by ultrasound-triggered oscillations and destruction of microbubbles. In this review, progress and challenges of USMB mediated drug delivery are summarized, with special focus on cancer therapy.

  16. Ultrasound-guided drug delivery in cancer

    Directory of Open Access Journals (Sweden)

    Sayan Mullick Chowdhury

    2017-07-01

    Full Text Available Recent advancements in ultrasound and microbubble (USMB mediated drug delivery technology has shown that this approach can improve spatially confined delivery of drugs and genes to target tissues while reducing systemic dose and toxicity. The mechanism behind enhanced delivery of therapeutics is sonoporation, the formation of openings in the vasculature, induced by ultrasound-triggered oscillations and destruction of microbubbles. In this review, progress and challenges of USMB mediated drug delivery are summarized, with special focus on cancer therapy.

  17. Destruction of a Magnetized Star

    Science.gov (United States)

    Kohler, Susanna

    2017-01-01

    completely.Amplifying EncountersFor stars that survive their encounter with the black hole, Guillochon and McCourt find that the process of partial disruption and re-accretion can amplify the magnetic field of the star by up to a factor of 20. Repeated encounters of the star with the black hole could amplify the field even more.The authors suggest an interesting implication of this idea: a population of highly magnetized stars may have formed in our own galactic center, resulting from their encounters with the supermassive black hole Sgr A*.A turbulent magnetic field forms after a partial stellar disruption and re-accretion of the tidal tails. [Adapted from Guillochon McCourt 2017]Effects in DestructionFor stars that are completely shredded and form a tidal stream after their encounter with the black hole, the authors find that the magnetic field geometry straightens within the stream of debris. There, the pressure of the magnetic field eventually dominates over the gas pressure and self-gravity.Guillochon and McCourt find that the fields new configuration isnt ideal for powering jets from the black hole but it is strong enough to influence how the stream interacts with itself and its surrounding environment, likely affecting what we can expect to see from these short-lived events.These simulations have clearly demonstrated the need to further explore the role of magnetic fields in the disruptions of stars by black holes.BonusCheck out the full (brief) video from one of the simulations by Guillochon and McCourt (be sure to watch it in high-res!). It reveals the evolution of a stars magnetic field configuration as the star is partially disrupted by the forces of a supermassive black hole and then re-accretes.CitationJames Guillochon and Michael McCourt 2017 ApJL 834 L19. doi:10.3847/2041-8213/834/2/L19

  18. Destruction of metallic foils under laser radiation

    International Nuclear Information System (INIS)

    Khokhlov, N.P.; Lisitsyn, Yu.V.; Mineev, V.N.; Ivanov, A.G.

    1975-01-01

    Experimental results are presented which illustrate the process of destruction of aluminium, lead and tantalum foils under irradiation of a neodymium laser, working in free generation regime with a power density varying from 5.10 5 - 5.10 6 wt/sq.cm. Calorimeters and photocells sensitive to the radiation with lambda=1.06 have been used for measuring the energy and recording the shape of the radiation pulse incident onto the target and passing through the disintegration products. The weight of the target has been determined prior to and after the experiment to find out the weight of Δm material expelled from the target. Rates of product scattering and a target destruction period, an amount of the material expelled and parameters of the radiation passing through the disintegration products have been determined as a function of the power density and an angle of the radiation incidence on the surface of the specimens. Average densities and absorption coefficients of the disintegration products of the foils under study have been assessed. A comparison of the characteristics of the metal foil (t 1 j) destruction in Pb-Ta-Al series with the metal thermal properties in this series shows that the destruction characteristics periodically vary as heat capacity, thermal conduction, evaporation heat and melting heat alter. A period of the target destruction becomes longer and the expelled mass smaller as the aforesaid thermal properties of the metals in Pb-Ta-Al series intensity [ru

  19. Destruction as a Step in Heidegger's Phenomenology

    Directory of Open Access Journals (Sweden)

    M.J Safian

    2014-08-01

    Full Text Available One of the most controversial issues in Heidegger’s philosophy is his claim that western philosophy tradition has overlooked the issue of Being. Heidegger’s attempt is to reveal the origins of this negligence by means of destruction. However, it seems that through such claim Heidegger aims to destroy and disvalue this tradition. In addition to defining and explaining destruction, our purpose in this article is to show that Heidegger’s goal is not to destroy the tradition of philosophy but the term destruction refers to a process which is a step in Heidegger’s phenomenology by means of which one can conceive and perceive Being better because only through such destruction ontology can fully assure itself in a phenomenological way of the genuine character of its concepts. The necessity of doing destruction in Heidegger’s thought has also been discussed and his persistence on it has been shown in two of his works, one belongs to early and another to later Heidegger.

  20. Size-sensitive particle trajectories in three-dimensional micro-bubble acoustic streaming flows

    Science.gov (United States)

    Volk, Andreas; Rossi, Massimiliano; Hilgenfeldt, Sascha; Rallabandi, Bhargav; Kähler, Christian; Marin, Alvaro

    2015-11-01

    Oscillating microbubbles generate steady streaming flows with interesting features and promising applications for microparticle manipulation. The flow around oscillating semi-cylindrical bubbles has been typically assumed to be independent of the axial coordinate. However, it has been recently revealed that particle motion is strongly three-dimensional: Small tracer particles follow vortical trajectories with pronounced axial displacements near the bubble, weaving a toroidal stream-surface. A well-known consequence of bubble streaming flows is size-dependent particle migration, which can be exploited for sorting and trapping of microparticles in microfluidic devices. In this talk, we will show how the three-dimensional toroidal topology found for small tracer particles is modified as the particle size increases up to 1/3 of the bubble radius. Our results show size-sensitive particle positioning along the axis of the semi-cylindrical bubble. In order to analyze the three-dimensional sorting and trapping capabilities of the system, experiments with an imposed flow and polydisperse particle solutions are also shown.

  1. Size-based sorting of micro-particles using microbubble streaming

    Science.gov (United States)

    Wang, Cheng; Jalikop, Shreyas; Hilgenfeldt, Sascha

    2009-11-01

    Oscillating microbubbles driven by ultrasound have shown great potential in microfluidic applications, such as transporting particles and promoting mixing [1-3]. The oscillations generate secondary steady streaming that can also trap particles. We use the streaming to develop a method of sorting particles of different sizes in an initially well-mixed solution. The solution is fed into a channel consisting of bubbles placed periodically along a side wall. When the bubbles are excited by an ultrasound piezo-electric transducer to produce steady streaming, the flow field is altered by the presence of the particles. This effect is dependent on particle size and results in size-based sorting of the particles. The effectiveness of the separation depends on the dimensions of the bubbles and particles as well as on the ultrasound frequency. Our experimental studies are aimed at a better understanding of the design and control of effective microfluidic separating devices. Ref: [1] P. Marmottant and S. Hilgenfeldt, Nature 423, 153 (2003). [2] P. Marmottant and S. Hilgenfeldt, Proc. Natl. Acad. Science USA, 101, 9523 (2004). [3] P. Marmottant, J.-P. Raven, H. Gardeniers, J. G. Bomer, and S. Hilgenfeldt, J. Fluid Mech., vol.568, 109 (2006).

  2. Low-pressure pulsed focused ultrasound with microbubbles promotes an anticancer immunological response.

    Science.gov (United States)

    Liu, Hao-Li; Hsieh, Han-Yi; Lu, Li-An; Kang, Chiao-Wen; Wu, Ming-Fang; Lin, Chun-Yen

    2012-11-11

    High-intensity focused-ultrasound (HIFU) has been successfully employed for thermal ablation of tumors in clinical settings. Continuous- or pulsed-mode HIFU may also induce a host antitumor immune response, mainly through expansion of antigen-presenting cells in response to increased cellular debris and through increased macrophage activation/infiltration. Here we demonstrated that another form of focused ultrasound delivery, using low-pressure, pulsed-mode exposure in the presence of microbubbles (MBs), may also trigger an antitumor immunological response and inhibit tumor growth. A total of 280 tumor-bearing animals were subjected to sonographically-guided FUS. Implanted tumors were exposed to low-pressure FUS (0.6 to 1.4 MPa) with MBs to increase the permeability of tumor microvasculature. Tumor progression was suppressed by both 0.6 and 1.4-MPa MB-enhanced FUS exposures. We observed a transient increase in infiltration of non-T regulatory (non-Treg) tumor infiltrating lymphocytes (TILs) and continual infiltration of CD8+ cytotoxic T-lymphocytes (CTL). The ratio of CD8+/Treg increased significantly and tumor growth was inhibited. Our findings suggest that low-pressure FUS exposure with MBs may constitute a useful tool for triggering an anticancer immune response, for potential cancer immunotherapy.

  3. Dependence of the subharmonic signal from contrast agent microbubbles on ambient pressure: A theoretical analysis.

    Science.gov (United States)

    Jiménez-Fernández, J

    2018-01-01

    This paper investigates the dependence of the subharmonic response in a signal scattered by contrast agent microbubbles on ambient pressure to provide quantitative estimations of local blood pressure. The problem is formulated by assuming a gas bubble encapsulated by a shell of finite thickness with dynamic behavior modeled by a nonlinear viscoelastic constitutive equation. For ambient overpressure compatible with the clinical range, the acoustic pressure intervals where the subharmonic signal may be detected (above the threshold for the onset and below the limit value for the first chaotic transition) are determined. The analysis shows that as the overpressure is increased, all harmonic components are displaced to higher frequencies. This displacement is significant for the subharmonic of order 1/2 and explains the increase or decrease in the subharmonic amplitude with ambient pressure described in previous works. Thus, some questions related to the monotonic dependence of the subharmonic amplitude on ambient pressure are clarified. For different acoustic pressures, quantitative conditions for determining the intervals where the subharmonic amplitude is a monotonic or non-monotonic function of the ambient pressure are provided. Finally, the influence of the ambient pressure on the subharmonic resonance frequency is analyzed.

  4. Thrombin-Activatable Microbubbles as Potential Ultrasound Contrast Agents for the Detection of Acute Thrombosis.

    Science.gov (United States)

    Lux, Jacques; Vezeridis, Alexander M; Hoyt, Kenneth; Adams, Stephen R; Armstrong, Amanda M; Sirsi, Shashank R; Mattrey, Robert F

    2017-11-01

    Acute deep vein thrombosis (DVT) is the formation of a blood clot in the deep veins of the body that can lead to fatal pulmonary embolism. Acute DVT is difficult to distinguish from chronic DVT by ultrasound (US), the imaging modality of choice, and is therefore treated aggressively with anticoagulants, which can lead to internal bleeding. Here we demonstrate that conjugating perfluorobutane-filled (PFB-filled) microbubbles (MBs) with thrombin-sensitive activatable cell-penetrating peptides (ACPPs) could lead to the development of contrast agents that detect acute thrombosis with US imaging. Successful conjugation of ACPP to PFB-filled MBs was confirmed by fluorescence microscopy and flow cytometry. Fluorescein-labeled ACPP was used to evaluate the efficiency of thrombin-triggered cleavage by measuring the mean fluorescence intensity of ACPP-labeled MBs (ACPP-MBs) before and after incubation at 37 °C with thrombin. Lastly, control MBs and ACPP-MBs were infused through a tube containing a clot, and US contrast enhancement was measured with or without the presence of a thrombin inhibitor after washing the clot with saline. With thrombin activity, 91.7 ± 14.2% of the signal was retained after ACPP-MB infusion and washing, whereas only 16.7 ± 4% of the signal was retained when infusing ACPP-MBs in the presence of hirudin, a potent thrombin inhibitor.

  5. Blood-brain barrier disruption induced by diagnostic ultrasound combined with microbubbles in mice.

    Science.gov (United States)

    Zhao, Bingxia; Chen, Yihan; Liu, Jinfeng; Zhang, Li; Wang, Jing; Yang, Yali; Lv, Qing; Xie, Mingxing

    2018-01-12

    To investigate the effects of the microbubble (MB) dose, mechanism index (MI) and sonication duration on blood-brain barrier (BBB) disruption induced by diagnostic ultrasound combined with MBs as well as to investigate the potential molecular mechanism. The extent of BBB disruption increased with MB dose, MI and sonication duration. A relatively larger extent of BBB disruption associated with minimal tissue damage was achieved by an appropriate MB dose and ultrasound exposure parameters with diagnostic ultrasound. Decreased expression of ZO-1, occludin and claudin-5 were correlated with disruption of the BBB, as confirmed by paracellular passage of the tracer lanthanum nitrate into the brain parenchyma after BBB disruption. These findings indicated that this technique is a promising tool for promoting brain delivery of diagnostic and therapeutic agents in the diagnosis and treatment of brain diseases. The extent of BBB disruption was qualitatively assessed by Evans blue (EB) staining and quantitatively analyzed by an EB extravasation measurement. A histological examination was performed to evaluate tissue damage. Expression of tight junction (TJ) related proteins ZO-1, occludin and claudin-5 was determined by western blotting analysis and immunohistofluorescence. Transmission electron microscopy was performed to observe ultrastructure changes of TJs after BBB disruption.

  6. A hemispherical microfluidic channel for the trapping and passive dissipation of microbubbles

    International Nuclear Information System (INIS)

    Kang, Edward; Lee, Dae Ho; Kim, Chang-Beom; Yoo, Sung Ju; Lee, Sang-Hoon

    2010-01-01

    In this paper, we present that trapping and dissipating of bubbles in a microfluidic cell culture system can be simultaneously achieved by utilizing curved geometry principles. For this end, a simple and cost-effective method to fabricate a curved hemispherical microfluidic channel is presented. On the basis of an analytical model, the mechanism that the hemispherical well can trap various sizes of bubbles better than the cylindrical well is described, and we present a quantitative comparison of the trapping capabilities of the hemispherical versus conventional cylindrical wells through experiments. The surface tension is another important factor to trap bubbles, which was also verified through the analysis and experiments. In the hemispherical wells, the trapped bubbles were spontaneously dissipated under the flowing condition without using any active source, and we characterized the degassing process by measuring the area of bubbles occupied in the well over time. For an application to a biomedical system, a cell culture chamber was combined with the bubble trapping system, and the performance of the system was verified by culturing HeLa cells with the flowing bubbled culture media. Conclusively, the suggested method demonstrated excellent performance in trapping of microbubbles and dissipation without using any peripheral device, and will be broadly applied in biomedical microfluidic research

  7. Growth and decay dynamics of a stable microbubble produced at the end of a near-field scanning optical microscopy fiber probe

    International Nuclear Information System (INIS)

    Taylor, R.S.; Hnatovsky, C.

    2004-01-01

    Low power cw laser radiation coupled into a near-field scanning optical microscopy fiber probe has been used to generate a stable microbubble in water. A probe tip which was selectively chemically etched and metallized served as a microheater for the generation of the stable bubble. Bubble diameters in the range of 40-400 μm and lifetimes of over an hour have been obtained. The microbubble exhibited a linear growth phase over a period of a few seconds before reaching a maximum diameter which depended on the laser power. When the laser beam was blocked the microbubble decayed with a rate which was inversely proportional to the bubble diameter. The bubble lifetime depended on the square of the initial bubble diameter. Instabilities which transform a large stable bubble into a microjet stream of micron sized bubbles as the laser power was increased is also described

  8. Orbital roof encephalocele mimicking a destructive neoplasm.

    Science.gov (United States)

    Alsuhaibani, Adel H; Hitchon, Patrick W; Smoker, Wendy R K; Lee, Andrew G; Nerad, Jeffrey A

    2011-01-01

    The purpose of this case report is to report an orbital roof encephalocele mimicking a destructive orbital neoplasm. Orbital roof encephalocele is uncommon but can mimic neoplasm. One potential mechanism for the orbital roof destruction is a post-traumatic "growing orbital roof fracture." The growing fracture has been reported mostly in children but can occur in adults. Alternative potential etiologies for the encephalocele are discussed, including Gorham syndrome. Orbital roof encephalocele is uncommon in adults, and the findings can superficially resemble an orbital neoplasm. Radiographic and clinical features that might suggest the correct diagnosis include a prior history of trauma, overlying frontal lobe encephalomalacia without significant mass effect or edema, and an orbital roof defect. The "growing fracture" mechanism may be a potential explanation for the orbital roof destruction in some cases.

  9. Collision-induced destructive quantum interference

    International Nuclear Information System (INIS)

    Yang Xihua; Sun Zhenrong; Zhang Shi'an; Ding Liang'en; Wang Zugeng

    2005-01-01

    We conduct theoretical studies on the collision-induced destructive quantum interference of two-colour two-photon transitions in an open rhomb-type five-level system with a widely separated doublet by the density matrix approach. The effects of the collision-induced decay rates, the ratio of the transition dipole moments and the energy separation of the doublet on the interference are analysed. It is shown that a narrow dip appears in the excitation spectrum due to the collision-induced destructive interference, and that the narrow interference dip still exists even when the collision broadening is comparable to the energy separation of the doublet. The physical origin of the collision-induced destructive quantum interference is analysed in the dressed-atom picture

  10. Non-destructive testing. V. 2

    International Nuclear Information System (INIS)

    Farley, J.M.; Nichols, R.W.

    1988-01-01

    The book entitled 'Non-destructive Testing' Volume 2, contains the proceedings of the fourth European Conference, organized by the British Institute of Non-Destructive Testing and held in London, September 1987. The volume contains seven chapters which examine the reliability of NDT, the economics of NDT and the use of NDT in:- civil engineering; oil, gas, coal and petrochemical industries; iron and steel industries; aerospace industry; and the nuclear and electricity supply industries. The seven chapters contain 78 papers, of which 19 are selected for INIS and indexed separately. (U.K.)

  11. Non-destructive testing of electronic parts

    International Nuclear Information System (INIS)

    Widenhorn, G.

    1980-01-01

    The requirements on quality, safety, faultlessness and reliability of electric components increase because of the high complexity of the appliances in which they are used. By means of examples a survey is given on the common non-destructive testing methods, testing operation and evaluation of test results on electric components which must meet in their application high requirements on quality and reliability. Defective components, especially those with hidden failures are sorted out by non-destructive testing and the failure frequency of the appliances and plants in testing and operation is greatly reduced. (orig.) [de

  12. Thermographic and potentiometric research on thermal destruction

    Energy Technology Data Exchange (ETDEWEB)

    Mel' nichuk, A.Yu.; Fialkov, B.S.; Zazharov, A.G.; Lemke, E.R.

    1981-03-01

    Analyses of thermal effects and electric potential during the thermal destruction of various types of solid fuels were conducted by means of thermography and electron-ion phenomena determination. The characteristics of coals of various ranks, and of graphite and coke are presented. Thermograms and potential curves are graphed. The studies showed a certain correlation between the thermograms and potential change curves of the solid phase. The character of the potential curves and intensity of their peaks depends on the type of sample and makes an evaluation on the charged state of the products of destruction possible. (8 refs.) (In Russian)

  13. European Non Destructive Examination Forum (ENDEF)

    International Nuclear Information System (INIS)

    Deffrennes, M.; Engl, G.; Estorff, U. von

    1998-01-01

    Non destructive examination (NDE) during fabrication, Pre-service inspection (PSI) and In service inspection (ISI) are considered key issues for the safe use of nuclear energy. They are important elements of plant lifetime management which is a critical item in decision making on nuclear policies. The European non destructive examination forum (ENDEF) founded by European Commission provides a platform for open discussion between representatives of the European industries with the purpose to establish cooperation between EU, Central and Eastern European Countries and New Independent States in the field of NDE and ISI

  14. Development of the destruction technology for radioactive organic solid wastes

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Won Zin; Park, H.S.; Lee, K.W. [and others

    1999-04-01

    The followings were studied through the project entitled 'Technology development for nuclear fuel cycle waste treatment'. 1. Organic waste decomposition technology development A. Destruction technology for organic wastes using Ag(2)-mediated electrochemical oxidation B. Recovery and regeneration technology for the spent chemicals used in the MEO process 2. Radioactive metal waste recycling technology A. Surface decontamination processes B. Decontamination waste treatment technology 3. Volume reduction technology nuclear fuel cycle (NFC) technology A. Estimation of the amount of radwastes and the optimum volume reduction methodology of domestic NFC B. Pretreatment of spent fuel cladding by electrochemical decontamination C. Hot cell process technology for the treatment of NFC wastes 4. Design and fabrication of the test equipment of volume reduction and reuse of alpha contaminated wastes 5. Evaluation on environmental compatibility of NFC A. Development of evaluation methodology on environmental friendliness of NFC B. Residual activity assessment of recycling wastes. (author). 321 refs., 54 tabs., 183 figs.

  15. Development of the destruction technology for radioactive organic solid wastes

    International Nuclear Information System (INIS)

    Oh, Won Zin; Park, H.S.; Lee, K.W.

    1999-04-01

    The followings were studied through the project entitled 'Technology development for nuclear fuel cycle waste treatment'. 1. Organic waste decomposition technology development A. Destruction technology for organic wastes using Ag(2)-mediated electrochemical oxidation B. Recovery and regeneration technology for the spent chemicals used in the MEO process 2. Radioactive metal waste recycling technology A. Surface decontamination processes B. Decontamination waste treatment technology 3. Volume reduction technology nuclear fuel cycle (NFC) technology A. Estimation of the amount of radwastes and the optimum volume reduction methodology of domestic NFC B. Pretreatment of spent fuel cladding by electrochemical decontamination C. Hot cell process technology for the treatment of NFC wastes 4. Design and fabrication of the test equipment of volume reduction and reuse of alpha contaminated wastes 5. Evaluation on environmental compatibility of NFC A. Development of evaluation methodology on environmental friendliness of NFC B. Residual activity assessment of recycling wastes. (author). 321 refs., 54 tabs., 183 figs

  16. Nonthermal ablation with microbubble-enhanced focused ultrasound close to the optic tract without affecting nerve function.

    Science.gov (United States)

    McDannold, Nathan; Zhang, Yong-Zhi; Power, Chanikarn; Jolesz, Ferenc; Vykhodtseva, Natalia

    2013-11-01

    Tumors at the skull base are challenging for both resection and radiosurgery given the presence of critical adjacent structures, such as cranial nerves, blood vessels, and brainstem. Magnetic resonance imaging-guided thermal ablation via laser or other methods has been evaluated as a minimally invasive alternative to these techniques in the brain. Focused ultrasound (FUS) offers a noninvasive method of thermal ablation; however, skull heating limits currently available technology to ablation at regions distant from the skull bone. Here, the authors evaluated a method that circumvents this problem by combining the FUS exposures with injected microbubble-based ultrasound contrast agent. These microbubbles concentrate the ultrasound-induced effects on the vasculature, enabling an ablation method that does not cause significant heating of the brain or skull. In 29 rats, a 525-kHz FUS transducer was used to ablate tissue structures at the skull base that were centered on or adjacent to the optic tract or chiasm. Low-intensity, low-duty-cycle ultrasound exposures (sonications) were applied for 5 minutes after intravenous injection of an ultrasound contrast agent (Definity, Lantheus Medical Imaging Inc.). Using histological analysis and visual evoked potential (VEP) measurements, the authors determined whether structural or functional damage was induced in the optic tract or chiasm. Overall, while the sonications produced a well-defined lesion in the gray matter targets, the adjacent tract and chiasm had comparatively little or no damage. No significant changes (p > 0.05) were found in the magnitude or latency of the VEP recordings, either immediately after sonication or at later times up to 4 weeks after sonication, and no delayed effects were evident in the histological features of the optic nerve and retina. This technique, which selectively targets the intravascular microbubbles, appears to be a promising method of noninvasively producing sharply demarcated lesions in

  17. Optical Spring Effect in Micro-Bubble Resonators and Its Application for the Effective Mass Measurement of Optomechanical Resonant Mode

    OpenAIRE

    Zhenmin Chen; Xiang Wu; Liying Liu; Lei Xu

    2017-01-01

    In this work, we present a novel approach for obtaining the effective mass of mechanical vibration mode in micro-bubble resonators (MBRs). To be specific, the effective mass is deduced from the measurement of optical spring effect (OSE) in MBRs. This approach is demonstrated and applied to analyze the effective mass of hollow MBRs and liquid-filled MBRs, respectively. It is found that the liquid-filled MBRs has significantly stronger OSE and a less effective mass than hollow MBRs, both of the...

  18. Creative Destruction in Libraries: Designing our Future

    Directory of Open Access Journals (Sweden)

    Caro Pinto

    2013-11-01

    Full Text Available In Brief: Joseph Schumpeter defines creative destruction as a “process of industrial mutation that incessantly revolutionizes the economic structure from within, incessantly destroying the old one, incessantly creating a new one.” As libraries struggle with how to position themselves to thrive in the digital age, how can we balance the traditional elements of librarianship like […

  19. Unceratainty of Heisenberg in Universe Destruction

    Directory of Open Access Journals (Sweden)

    Sri Jumini

    2017-12-01

    Full Text Available The Qur'an is a guidence which explaines all about the universe to human being. The discovery of science has been able to explain the truth of the Qur'an scientifically. One of which is the principle of Heisenberg's uncertainty in the event of the universe destruction. The purpose of this research is to know: 1 Science's view of the event of the universe destruction (Big Crunch in Qur’an [Al Infithaar]: 1-3, and How the relation of Heisenberg’s uncertainty principles and the law of thermodynamics II toward  the collapse of the universe (Big Crunch based on Scientific views and the Quran. This research is a qualitative research using library research method which analyzes the related books directly or indirectly. The results of the analysis stated that: 1 The concentration of mass, which is big enough, relates to some of the laws of physics, those are: Relativity, Heisenberg's uncertainty principles, and the law of Thermodynamic II; 2 The universe will return at its sole point, i.e; the absence of the universe; 3 The destruction of the universe is the destruction of the order of the universe which then the stars fall scatteredly because of the gravitational force that prevents them disappears, the balance of the universe diminishes, decreases and becomes uncertain, and eventually disappears.

  20. New tasks for non-destructive testing

    International Nuclear Information System (INIS)

    1990-01-01

    The proceedings contain 29 lectures and 43 posters which were presented in Trier at the annual meeting of the DGZfP in May 1990. The contributions report on further development of non-destructive testing methods towards more reliability, both of inspections and with regard to interpretation of the results. (MM) [de

  1. Complete destructive interference of partially coherent fields

    NARCIS (Netherlands)

    Gbur, G.J.; Visser, T.D.; Wolf, E.

    2004-01-01

    A three-point source model is used to study the interference of wavefields which are mutually partially coherent. It is shown that complete destructive interference of the fields is possible in such a "three-pinhole interferometer" even if the sources are not fully coherent with respect to each

  2. Utilization of radiation in non destructive tests

    International Nuclear Information System (INIS)

    Lopes, R.T.; Jesus, E.F.O. de; Junqueira, M.M.; Matos, J.A. de; Castello Branco, L.M.; Barros Junior, J.D.; Borges, J.C.

    1987-01-01

    The Nuclear Instrumentation Laboratory from COPPE/UFRJ has been developed techniques for using nuclear radiations to obtain images for non-destructive materials testing and medicine. With this objective, some prototypes of transmission computerized tomography systems using parallel beans and fan beans, with computer automation, including the mathematical process of image reprocessing and presentation in videos or printers are constructed [pt

  3. Delineating the sequelae of destructive and constructive interparental conflict for children within an evolutionary framework.

    Science.gov (United States)

    Davies, Patrick T; Martin, Meredith J; Cicchetti, Dante

    2012-07-01

    We examined the joint role of constructive and destructive interparental conflict in predicting children's emotional insecurity and psychological problems. In Study 1, 250 early adolescents (M = 12.6 years) and their primary caregivers completed assessments of family and child functioning. In Study 2, 201 mothers and their 2-year-old children participated in a multimethod, longitudinal design with 3 annual measurement occasions. Findings from structural equation modeling in both studies revealed that children's emotional insecurity in the interparental relationship mediated associations between destructive interparental conflict and children's psychological problems even after including constructive conflict and family and child covariates as predictors. Conversely, emotional insecurity was not a mediator of associations between constructive interparental conflict and children's psychological problems when destructive interparental conflict was specified as a risk factor in the analyses. The results are consistent with the evolutionary reformulation of emotional security theory and the resulting primacy ascribed to destructive interparental conflict in accounting for individual differences in children's emotional insecurity and its pathogenic implications (Davies & Sturge-Apple, 2007).

  4. Ultrasound-mediated gene delivery of naked plasmid DNA in skeletal muscles: a case for bolus injections.

    Science.gov (United States)

    Sanches, Pedro Gomes; Mühlmeister, Mareike; Seip, Ralf; Kaijzel, Eric; Löwik, Clemens; Böhmer, Marcel; Tiemann, Klaus; Grüll, Holger

    2014-12-10

    Localized gene delivery has many potential clinical applications. However, the nucleic acids (e.g. pDNA and siRNA) are incapable of passively crossing the endothelium, cell membranes and other biological barriers which must be crossed to reach their intracellular targets. A possible solution is the use of ultrasound to burst circulating microbubbles inducing transient permeabilization of surrounding tissues which mediates nucleic acid extravasation and cellular uptake. In this study we report on an optimization of the ultrasound gene delivery technique. Naked pDNA (200 μg) encoding luciferase and SonoVue® microbubbles were co-injected intravenously in mice. The hindlimb skeletal muscles were exposed to ultrasound from a non-focused transducer (1 MHz, 1.25 MPa, PRI 30s) and injection protocols and total amounts as well as ultrasound parameters were systemically varied. Gene expression was quantified relative to a control using a bioluminescence camera system at day 7 after sonication. Bioluminescence ratios in sonicated/control muscles of up to 101× were obtained. In conclusion, we were able to specifically deliver genetic material to the selected skeletal muscles and overall, the use of bolus injections and high microbubble numbers resulted in increased gene expression reflected by stronger bioluminescence signals. Based on our data, bolus injections seem to be required in order to achieve transient highly concentrated levels of nucleic acids and microbubbles at the tissue of interest which upon ultrasound exposure should lead to increased levels of gene delivery. Thus, ultrasound mediated gene delivery is a promising technique for the clinical translation of localized drug delivery. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Investigation on the inertial cavitation threshold and shell properties of commercialized ultrasound contrast agent microbubbles.

    Science.gov (United States)

    Guo, Xiasheng; Li, Qian; Zhang, Zhe; Zhang, Dong; Tu, Juan

    2013-08-01

    The inertial cavitation (IC) activity of ultrasound contrast agents (UCAs) plays an important role in the development and improvement of ultrasound diagnostic and therapeutic applications. However, various diagnostic and therapeutic applications have different requirements for IC characteristics. Here through IC dose quantifications based on passive cavitation detection, IC thresholds were measured for two commercialized UCAs, albumin-shelled KangRun(®) and lipid-shelled SonoVue(®) microbubbles, at varied UCA volume concentrations (viz., 0.125 and 0.25 vol. %) and acoustic pulse lengths (viz., 5, 10, 20, 50, and 100 cycles). Shell elastic and viscous coefficients of UCAs were estimated by fitting measured acoustic attenuation spectra with Sarkar's model. The influences of sonication condition (viz., acoustic pulse length) and UCA shell properties on IC threshold were discussed based on numerical simulations. Both experimental measurements and numerical simulations indicate that IC thresholds of UCAs decrease with increasing UCA volume concentration and acoustic pulse length. The shell interfacial tension and dilatational viscosity estimated for SonoVue (0.7 ± 0.11 N/m, 6.5 ± 1.01 × 10(-8) kg/s) are smaller than those of KangRun (1.05 ± 0.18 N/m, 1.66 ± 0.38 × 10(-7) kg/s); this might result in lower IC threshold for SonoVue. The current results will be helpful for selecting and utilizing commercialized UCAs for specific clinical applications, while minimizing undesired IC-induced bioeffects.

  6. Nonconventional concrete hollow blocks evaluation by destructive and non-destructive testing

    Directory of Open Access Journals (Sweden)

    M.S. Rodrigues

    Full Text Available The aim of this study was to evaluate cementitious matrices properties by partial replacement of Portland cement by silica fume (SF or by rice husk ash (RHA, and their application in nonbearing hollow blocks, tested by destructive and non-destructive methods. The following mixtures were produced: reference (100% of Portland cement and Portland cement replacement (10% by mass with SF or RHA. The non-destructive testing showed that the highest values of UPV were obtained for SF-based blocks and RHA-based blocks. The destructive test showed better results for SF-based blocks, but there was no statistical difference between the RHA-based and control ones.

  7. Microbubble-Triggered Spontaneous Separation of Transparent Thin Films from Substrates Using Evaporable Core-Shell Nanocapsules.

    Science.gov (United States)

    Son, Intae; Lee, Byungsun; Kim, Jae Hong; Kim, Chunho; Yoo, Ji Yong; Ahn, Byung Wook; Hwang, Jeongho; Lee, Jonghyuk; Lee, Jun Hyup

    2018-05-23

    The spontaneous separation of a polymer thin film from a substrate is an innovative technology that will enable material recycling and reduce manufacturing cost in the film industry, and this can be applied in a wide range of applications, from optical films to wearable devices. Here, we present an unprecedented spontaneous strategy for separating transparent polymer films from substrates on the basis of microbubble generation using nanocapsules containing an evaporable material. The core-shell nanocapsules are prepared from poly(methyl methacrylate)-polyethyleneimine nanoparticles via the encapsulation of methylcyclohexane (MCH). A spherical nanostructure with a vaporizable core is obtained, with the heat-triggered gas release ability leading to the formation of microbubbles. Our separation method applied to transparent polymer films doped with a small amount of the nanocapsules encapsulating evaporable MCH enables spontaneous detachment of thin films from substrates via vacuum-assisted rapid vaporization of MCH over a short separation time, and clear detachment of the film is achieved with no deterioration of the inherent optical transparency and adhesive property compared to a pristine film.

  8. Computer-assisted quantitative assessment of power Doppler US: effects of microbubble contrast agent in the differentiation of breast tumors

    International Nuclear Information System (INIS)

    Kettenbach, Joachim; Helbich, Thomas H.; Huber, Sabine; Zuna, Ivan; Dock, Wolfgang

    2005-01-01

    Rationale and objectives: To objectively quantify the effects of a microbubble contrast agent to differentiate breast tumors with power doppler ultrasound and to compare these results with color doppler ultrasound (CD US). Methods: In 47 patients a microbubble contrast agent was injected intravenously. Computer-assisted quantitative assessment of the color pixel density was performed to evaluate the increase in Doppler signals. Results were compared to previously published results of a color Doppler ultrasound study. Results: Peak color pixel density at contrast-enhanced power Doppler ultrasound was higher for carcinomas than for benign tumors (P < 0.03). Time to peak enhancement was shorter in carcinomas than in benign tumors (P < 0.01). For both parameters, diagnostic accuracy of power Doppler ultrasound was 69 and 78%, and for color Doppler ultrasound 62 and 76%, respectively. Conclusions: Quantitative assessment of contrast-enhanced power Doppler ultrasound showed significant differences in malignant and benign breast tumors. Diagnostic accuracy of contrast-enhanced power Doppler ultrasound was higher compared to color Doppler ultrasound

  9. Differences and similarity in the dynamic and acoustic properties of gas microbubbles in liquid mercury and water

    International Nuclear Information System (INIS)

    Ida, Masato; Haga, Katsuhiro; Kogawa, Hiroyuki; Naoe, Takashi; Futakawa, Masatoshi

    2010-01-01

    Differences and similarities in the dynamics of microbubbles in liquid mercury and water are clarified and summarized in order to evaluate the validity and usefulness of experiments with water as an alternative to experiments with mercury. Pressure-wave induced cavitation in liquid mercury is of particular concern in the high-power pulsed neutron sources working in Japan and the U.S. Toward suppressing the pressure waves and cavitation, injection of gas microbubbles into liquid mercury has been attempted. However, many difficulties arise in mercury experiments mainly because liquid mercury is an opaque liquid. Hence we and collaborators have performed water experiments as an alternative, in conjunction with mercury experiments. In this paper, we discussed how we should use the result with water and how we can make the water experiments meaningful. The non-dimensional numbers of bubbly liquids and bubbles' rise velocity, coalescence frequency, and response to heat input were investigated theoretically for both mercury and water. A suggestion was made to 'see through' bubble distribution in flowing mercury from the result of water study, and a notable similarity was found in the effect of bubbles to absorb thermal expansion of the liquids. (author)

  10. Ex Vivo Perfusion-Simulation Measurements of Microbubbles as a Scattering Contrast Agent for Grating-Based X-Ray Dark-Field Imaging.

    Directory of Open Access Journals (Sweden)

    Astrid Velroyen

    Full Text Available The investigation of dedicated contrast agents for x-ray dark-field imaging, which exploits small-angle scattering at microstructures for contrast generation, is of strong interest in analogy to the common clinical use of high-atomic number contrast media in conventional attenuation-based imaging, since dark-field imaging has proven to provide complementary information. Therefore, agents consisting of gas bubbles, as used in ultrasound imaging for example, are of particular interest. In this work, we investigate an experimental contrast agent based on microbubbles consisting of a polyvinyl-alcohol shell with an iron oxide coating, which was originally developed for multimodal imaging and drug delivery. Its performance as a possible contrast medium for small-animal angiography was examined using a mouse carcass to realistically consider attenuating and scattering background signal. Subtraction images of dark field, phase contrast and attenuation were acquired for a concentration series of 100%, 10% and 1.3% to mimic different stages of dilution in the contrast agent in the blood vessel system. The images were compared to the gold-standard iodine-based contrast agent Solutrast, showing a good contrast improvement by microbubbles in dark-field imaging. This study proves the feasibility of microbubble-based dark-field contrast-enhancement in presence of scattering and attenuating mouse body structures like bone and fur. Therefore, it suggests a strong potential of the use of polymer-based microbubbles for small-animal dark-field angiography.

  11. Modeling complicated rheological behaviors in encapsulating shells of lipid-coated microbubbles accounting for nonlinear changes of both shell viscosity and elasticity.

    Science.gov (United States)

    Li, Qian; Matula, Thomas J; Tu, Juan; Guo, Xiasheng; Zhang, Dong

    2013-02-21

    It has been accepted that the dynamic responses of ultrasound contrast agent (UCA) microbubbles will be significantly affected by the encapsulating shell properties (e.g., shell elasticity and viscosity). In this work, a new model is proposed to describe the complicated rheological behaviors in an encapsulating shell of UCA microbubbles by applying the nonlinear 'Cross law' to the shell viscous term in the Marmottant model. The proposed new model was verified by fitting the dynamic responses of UCAs measured with either a high-speed optical imaging system or a light scattering system. The comparison results between the measured radius-time curves and the numerical simulations demonstrate that the 'compression-only' behavior of UCAs can be successfully simulated with the new model. Then, the shell elastic and viscous coefficients of SonoVue microbubbles were evaluated based on the new model simulations, and compared to the results obtained from some existing UCA models. The results confirm the capability of the current model for reducing the dependence of bubble shell parameters on the initial bubble radius, which indicates that the current model might be more comprehensive to describe the complex rheological nature (e.g., 'shear-thinning' and 'strain-softening') in encapsulating shells of UCA microbubbles by taking into account the nonlinear changes of both shell elasticity and shell viscosity.

  12. Modeling complicated rheological behaviors in encapsulating shells of lipid-coated microbubbles accounting for nonlinear changes of both shell viscosity and elasticity

    International Nuclear Information System (INIS)

    Li Qian; Tu Juan; Guo Xiasheng; Zhang Dong; Matula, Thomas J

    2013-01-01

    It has been accepted that the dynamic responses of ultrasound contrast agent (UCA) microbubbles will be significantly affected by the encapsulating shell properties (e.g., shell elasticity and viscosity). In this work, a new model is proposed to describe the complicated rheological behaviors in an encapsulating shell of UCA microbubbles by applying the nonlinear ‘Cross law’ to the shell viscous term in the Marmottant model. The proposed new model was verified by fitting the dynamic responses of UCAs measured with either a high-speed optical imaging system or a light scattering system. The comparison results between the measured radius–time curves and the numerical simulations demonstrate that the ‘compression-only’ behavior of UCAs can be successfully simulated with the new model. Then, the shell elastic and viscous coefficients of SonoVue microbubbles were evaluated based on the new model simulations, and compared to the results obtained from some existing UCA models. The results confirm the capability of the current model for reducing the dependence of bubble shell parameters on the initial bubble radius, which indicates that the current model might be more comprehensive to describe the complex rheological nature (e.g., ‘shear-thinning’ and ‘strain-softening’) in encapsulating shells of UCA microbubbles by taking into account the nonlinear changes of both shell elasticity and shell viscosity. (paper)

  13. Assessment of portal venous system patency in the liver transplant candidate: A prospective study comparing ultrasound, microbubble-enhanced colour Doppler ultrasound, with arteriography and surgery

    International Nuclear Information System (INIS)

    Marshall, M.M.; Beese, R.C.; Muiesan, P.; Sarma, D.I.; O'Grady, J.; Sidhu, P.S.

    2002-01-01

    AIM: To determine the role of microbubble-enhanced colour Doppler ultrasound (CDUS) in assessing portal venous patency prior to liver transplantation. MATERIALS AND METHODS: Over a 2-year period, all patients with chronic liver disease undergoing routine pre-transplant CDUS examination in whom the portal venous system was inadequately demonstrated were recruited to the study. CDUS was performed in 368 patients and 33 patients (9%) were recruited. A repeat CDUS examination following an intravenous bolus injection of the microbubble contrast agent Levovist[reg] (Schering Healthcare AG, Berlin, Germany) was performed. Diagnostic confidence was recorded on a free linear analogue scale for both examinations. Findings were compared with indirect portography and surgery. RESULTS: Of the 33 patients with sub-optimal baseline examinations, improvement in portal vein visualization was achieved in 31 patients (94%). Median diagnostic confidence increased from 50% (interquartile range 30-60) to 90% (interquartile range 75-98) (P < 0.001) following administration of Levovist[reg]. Overall accuracy of portal vein assessment using microbubble-enhanced CDUS in 15 patients in whom a definitive diagnosis was made within 2 months was 87%. CONCLUSION: Microbubble-enhanced CDUS is a simple, inexpensive adjunct to standard pre liver transplant screening of the portal vein. It is particularly helpful in patients with end-stage cirrhosis who are at high risk of portal vein thrombosis and in whom the conventional examination is sub-optimal.Marshall, M.M. et al. (2002)

  14. Economic importance of non-destructive testing

    International Nuclear Information System (INIS)

    Loebert, P.

    1979-01-01

    On May 21 to 23, 1979, the annual meeting of the Deutsche Gesellschaft fuer Zerstoerungsfreie Pruefung took place in Lindau near the Bodensee lake. About 600 experts from Germany and abroad participated in the meeting, whose general subject was 'The Economic Importance of Non-Destructive Testing'. Theoretical problems and practical investigations were discussed in a number of papers on special subjects. Apart from the 33 papers, there was also a poster show with 53 stands with texts, drawings, diagrams, and figures where the authors informed those interested on the latest state of knowledge in testing. The short papers were read in six sessions under the headings of rentability of non-destructive testing, X-ray methods, electromagnetic methods, and ultrasonic methods 1 and 2. (orig.) [de

  15. The Creation and Destruction of Social Capital

    DEFF Research Database (Denmark)

    Svendsen, Gunnar Lind Haase; Svendsen, Gert Tinggaard

    ‘A welcome contribution to scholarly economic and public policy debates, The Creation and Destruction of Social Capital is written for advanced students yet offers insights critical to better understanding micro and macro economics alike.' - Willis M. Buhle, The Midwest Book Review ‘The Svendsens...... in to crafting this study.' - From the foreword by Elinor Ostrom Is social capital the ‘missing link' in economics? In this vital new book, the authors argue that the ‘forgotten' production factor of social capital is as crucial in economic decision-making as the other more traditional factors of production...... such as physical, financial and human capital. They attempt to bridge the gap between theory and reality by examining the main factors that determine entrepreneurship, co-operative movements and the creation and destruction of social capital....

  16. Non-destructive control of castings

    International Nuclear Information System (INIS)

    Boutault, J.; Mascre, C.

    1978-01-01

    The object of non-destructive control in foundries is to verify the metal structure, the absence of unacceptable discontinuity, total tightness, etc. This leads to a range of very varied controls according to the importance of the series, the quality level required by the specifications, the nature of the alloy. The originality of the solutions which are imperative for castings is shown through examples: casting of high quality complex forms in short series; very thick unit parts; very large series of parts requiring on efficient automation of non-destructive control. Lastly the publishing of testing methods and interpretating rules, which are the base of a friendly understanding between constructors and founders are recalled [fr

  17. Non-destructive control in nuclear construction

    International Nuclear Information System (INIS)

    Banus; Barbier; Launay

    1978-01-01

    Having recalled the characteristics of the fundamental components of the main primary circuit of nuclear boilers (900 MW) and the means appropriated for their control, it is recalled that the 'French Electricity Board's specifications and control rules' often prescribe more severe criteria than those existing in the U.S.A. Then practical examples of non-destructive controls concerning the steam generator end plates, vessel stainless steel linings, pump attachements, steam generator pipes are given [fr

  18. Polonium-210 as Weapon for Mass Destruction

    International Nuclear Information System (INIS)

    Koteng, A.O.

    2010-01-01

    Properties of Po-210 make it possible for its use as weapon of mass destruction. Po-210 occurs naturally in minute quantities in the human body, in Uranium ore (< 0.1 mg Po-210 / ton ) and as a product of Radon-222 gas decay chain. Po-210 also occurs as deposition on vegetation (tobacco leaves). Po-210 is produced by bombardment of Bi-209 with neutrons in a nuclear reactor. Russia produces 8 grams per year for export to USA market

  19. Destructive quantum interference in spin tunneling problems

    OpenAIRE

    von Delft, Jan; Henley, Christopher L.

    1992-01-01

    In some spin tunneling problems, there are several different but symmetry-related tunneling paths that connect the same initial and final configurations. The topological phase factors of the corresponding tunneling amplitudes can lead to destructive interference between the different paths, so that the total tunneling amplitude is zero. In the study of tunneling between different ground state configurations of the Kagom\\'{e}-lattice quantum Heisenberg antiferromagnet, this occurs when the spi...

  20. Development of non-destructive testing. Turkey

    International Nuclear Information System (INIS)

    1991-01-01

    A National Scheme for the qualification and certification of Non-Destructive Testing (NDT) personnel in various methods has been established as the first stage of implementation. Systematic training in such methods as radiography (RT), ultrasonics (UT), magnetic particles (MT), liquid penetrant (PT) and eddy currents (ET) at levels I, II and some at III has been initiated and should be continued. Direct link with the industry and continuous effort to extend practical applications is strongly recommended

  1. Early MRI findings of rapidly destructive coxarthrosis

    International Nuclear Information System (INIS)

    Watanabe, Wataru; Itoi, Eiji; Yamada, Shin

    2002-01-01

    Rapidly destructive coxarthrosis (RDC) is known to affect elderly women, but its etiology is unknown. This is the first report to our knowledge, based on a search of the English literature, that reveals the entire process of hip destruction from the onset to the terminal stage of RDC, in an 80-year-old woman. Radiographic evaluation showed subchondral insufficiency fracture of the femoral head at an early stage of this disease. An MRI examination within a month of the onset of hip pain showed the entire femoral head with low intensity on T1-weighted images and high intensity on T2-weighted images, and a small low-intensity band at the subchondral area of the lateral weight-bearing portion of the head. These findings are consistent with subchondral insufficiency fracture and associated bone marrow edema. The lesion developed into a deep and large erosion at the superolateral portion of the femoral head, the process being observed on both roentgenograms and MRI. These findings were confirmed during total hip arthroplasty. This case suggests that subchondral insufficiency fracture of the femoral head may be a preceding sign of destruction of the femoral head. (orig.)

  2. Weapons of mass destruction - current security threat

    International Nuclear Information System (INIS)

    Durdiak, J.; Gafrik, A.; Pulis, P.; Susko, M.

    2005-01-01

    This publication brings a complex and comprehensive view of the weapons of mass destruction phenomenon in the context of present military and political situation. It emphasizes the threat posed by proliferation of these destructive devices and their carriers as well as the threat present in their possession by unpredictable totalitarian regimes or terrorist groups. The publication is structured into four basic parts: Introduction Into The Topic, Nuclear Weapons, Chemical Weapons and Biological Weapons. The Introduction reflects the latest developments on the field of military technologies, which lead to the development of new destructive devices with characteristics comparable to basic types of WMDs - nuclear, chemical and biological. Based on the definition of WMD as 'weapon systems with enormous impact causing mass destruction, population, equipment and material losses', the modern mass destruction devices are assorted here, such as ecological, radiological and beam weapons, aerosol and container intelligent ammunition, the outburst of dangerous chemical substances from infrastructure, non-conventional weapons and military devices. The Nuclear Weapons part depicts the most destructive device of mass destruction mankind ever invented in close detail. It maps the history of most significant discoveries in nuclear physics, development and construction of the first nuclear weapons, accumulation of nuclear warheads and their carriers in the Cold war era, attempts of nuclear disarmament and reducing the number of nuclear weapons in possession of superpowers and their proliferation in the world's crisis regions including North Korea and Iran. The chapters devoted to theoretical grounds and physical principles of nuclear and thermonuclear weapons' functioning, the main categories and types, as well as destructive effects and consequences of use contain an adequate mathematical apparatus. This chapter's conclusion brings the overview of nuclear armament of states that

  3. DETERMINANTS DESTRUCTIVE TO BUSINESS CONDUCT TRANSPORT

    Directory of Open Access Journals (Sweden)

    Natalia Anatol’evna Loginova

    2017-03-01

    Full Text Available The article examines the determinants of destructive behavior in the transport business with the aim to identify their causes and to clarify the features of influence on them by all business stakeholders in transport. It is shown that the key determinants are: submission to the will of one business entity to another, the implementation of state support only in distressed periods of functioning of transport organizations, business obligations to the state are often perceived as a back-breaking businessmen, unfair, unnecessary. The main conclusions of the work are reduced to the following recommendations: to form a focused pulse of the state in support of the transport business; improve enforcement culture; more efficient use of the transport business capital. The goal – to identify the cause of the destructive business behavior and clarify the characteristics of their research on the part of all stakeholders in the transport sector. Method or methodology of work: in the article used analytical methods, and statistical analysis methods. Results for: received informative pictures that describe deterministic minanaty-destructive conduct business on the road, on the basis of which developed recommendations to neutralize their influence on the behavior of entrepreneurs. Application of results: the results the expediency applied differently businesses and government agencies operating in the field of transport.

  4. Responding to Destructive Interpersonal Interactions: A way forward ...

    African Journals Online (AJOL)

    Responding to Destructive Interpersonal Interactions: A way forward for ... cultural intolerance and other destructive interpersonal interactions and relationships clearly ... This work is licensed under a Creative Commons Attribution 3.0 License.

  5. ODS Destruction in the United States and Abroad - February 2018

    Science.gov (United States)

    This technical report provides information on sources, destruction technologies, and best practices for recovery, collection, transport, and destruction of ozone-depleting substances and other fluorinated compounds such as HFCs

  6. The synthesis, magnetic purification and evaluation of 99mTc-labeled microbubbles

    International Nuclear Information System (INIS)

    Lazarova, Neva; Causey, Patrick W.; Lemon, Jennifer A.; Czorny, Shannon K.; Forbes, John R.; Zlitni, Aimen; Genady, Afaf; Foster, F. Stuart; Valliant, John F.

    2011-01-01

    Introduction: Ultrasound (US) contrast agents based on microbubbles (MBs) are being investigated as platforms for drug and gene delivery. A methodology for determining the distribution and fate of modified MBs quantitatively in vivo can be achieved by tagging MBs directly with 99m Tc. This creates the opportunity to employ dual-modality imaging using both US and small animal SPECT along with quantitative ex vivo tissue counting to evaluate novel MB constructs. Methods: A 99m Tc-labeled biotin derivative ( 99m TcL1) was prepared and incubated with streptavidin-coated MBs. The 99m Tc-labeled bubbles were isolated using a streptavidin-coated magnetic-bead purification strategy that did not disrupt the MBs. A small animal scintigraphic/CT imaging study as well as a quantitative biodistribution study was completed using 99m TcL1 and 99m Tc-labeled bubbles in healthy C57Bl-6 mice. Results: The imaging and biodistribution data showed rapid accumulation and retention of 99m Tc-MBs in the liver (68.2±6.6 %ID/g at 4 min; 93.3±3.2 %ID/g at 60 min) and spleen (214.2±19.7 %ID/g at 4 min; 213.4±19.7 %ID/g at 60 min). In contrast, 99m TcL1 accumulated in multiple organs including the small intestine (22.5±3.6 %ID/g at 4 min; 83.4±5.9 %ID/g at 60 min) and bladder (184.0±88.1 %ID/g at 4 min; 24.2±17.7 %ID/g at 60 min). Conclusion: A convenient means to radiolabel and purify MBs was developed and the distribution of the labeled products determined. The result is a platform which can be used to assess the pharmacokinetics and fate of novel MB constructs both regionally using US and throughout the entire subject in a quantitative manner by employing small animal SPECT and tissue counting.

  7. Transfection effect of microbubbles on cells in superposed ultrasound waves and behavior of cavitation bubble.

    Science.gov (United States)

    Kodama, Tetsuya; Tomita, Yukio; Koshiyama, Ken-Ichiro; Blomley, Martin J K

    2006-06-01

    The combination of ultrasound and ultrasound contrast agents (UCAs) is able to induce transient membrane permeability leading to direct delivery of exogenous molecules into cells. Cavitation bubbles are believed to be involved in the membrane permeability; however, the detailed mechanism is still unknown. In the present study, the effects of ultrasound and the UCAs, Optison on transfection in vitro for different medium heights and the related dynamic behaviors of cavitation bubbles were investigated. Cultured CHO-E cells mixed with reporter genes (luciferase or beta-gal plasmid DNA) and UCAs were exposed to 1 MHz ultrasound in 24-well plates. Ultrasound was applied from the bottom of the well and reflected at the free surface of the medium, resulting in the superposition of ultrasound waves within the well. Cells cultured on the bottom of 24-well plates were located near the first node (displacement node) of the incident ultrasound downstream. Transfection activity was a function determined with the height of the medium (wave traveling distance), as well as the concentration of UCAs and the exposure time was also determined with the concentration of UCAs and the exposure duration. Survival fraction was determined by MTT assay, also changes with these values in the reverse pattern compared with luciferase activity. With shallow medium height, high transfection efficacy and high survival fraction were obtained at a low concentration of UCAs. In addition, capillary waves and subsequent atomized particles became significant as the medium height decreased. These phenomena suggested cavitation bubbles were being generated in the medium. To determine the effect of UCAs on bubble generation, we repeated the experiments using crushed heat-treated Optison solution instead of the standard microbubble preparation. The transfection ratio and survival fraction showed no additional benefit when ultrasound was used. These results suggested that cavitation bubbles created by the

  8. Dissociation of Tissue Destruction and Bacterial Expansion during Bubonic Plague.

    Directory of Open Access Journals (Sweden)

    Françoise Guinet

    2015-10-01

    Full Text Available Activation and/or recruitment of the host plasmin, a fibrinolytic enzyme also active on extracellular matrix components, is a common invasive strategy of bacterial pathogens. Yersinia pestis, the bubonic plague agent, expresses the multifunctional surface protease Pla, which activates plasmin and inactivates fibrinolysis inhibitors. Pla is encoded by the pPla plasmid. Following intradermal inoculation, Y. pestis has the capacity to multiply in and cause destruction of the lymph node (LN draining the entry site. The closely related, pPla-negative, Y. pseudotuberculosis species lacks this capacity. We hypothesized that tissue damage and bacterial multiplication occurring in the LN during bubonic plague were linked and both driven by pPla. Using a set of pPla-positive and pPla-negative Y. pestis and Y. pseudotuberculosis strains in a mouse model of intradermal injection, we found that pPla is not required for bacterial translocation to the LN. We also observed that a pPla-cured Y. pestis caused the same extensive histological lesions as the wild type strain. Furthermore, the Y. pseudotuberculosis histological pattern, characterized by infectious foci limited by inflammatory cell infiltrates with normal tissue density and follicular organization, was unchanged after introduction of pPla. However, the presence of pPla enabled Y. pseudotuberculosis to increase its bacterial load up to that of Y. pestis. Similarly, lack of pPla strongly reduced Y. pestis titers in LNs of infected mice. This pPla-mediated enhancing effect on bacterial load was directly dependent on the proteolytic activity of Pla. Immunohistochemistry of Pla-negative Y. pestis-infected LNs revealed extensive bacterial lysis, unlike the numerous, apparently intact, microorganisms seen in wild type Y. pestis-infected preparations. Therefore, our study demonstrates that tissue destruction and bacterial survival/multiplication are dissociated in the bubo and that the primary action of Pla

  9. Facing towards or Turning away from Destructive Narcissism

    Science.gov (United States)

    Flynn, Denis; Skogstad, Helga

    2006-01-01

    This paper presents a detailed theoretical discussion of destructive narcissism in relation to Freud and Rosenfeld and later theorists. In destructive narcissism, the destructiveness is itself idealised and overrides "the vital functions which serve the purpose of self-preservation" (Freud, S., 1914, "On narcissism" S.E. 14: 87)--a feature which…

  10. 7 CFR 160.9 - Destructively distilled wood turpentine.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Destructively distilled wood turpentine. 160.9 Section... REGULATIONS AND STANDARDS FOR NAVAL STORES General § 160.9 Destructively distilled wood turpentine. The designation “destructively distilled wood turpentine” shall refer to the kind of spirits of turpentine...

  11. Physical basis of destruction of concrete and other building materials

    Science.gov (United States)

    Suleymanova, L. A.; Pogorelova, I. A.; Kirilenko, S. V.; Suleymanov, K. A.

    2018-03-01

    In the article the scientifically-grounded views of authors on the physical essence of destruction process of concrete and other materials are stated; it is shown that the mechanism of destruction of materials is similar in its essence during the mechanical, thermal, physical-chemical and combined influences, and that in its basis Newton's third law lays. In all cases destruction consists in decompaction of structures, loosening of the internal bonds in materials, in the further integrity damage and their division into separate loosely-bound (full destruction) and unbound with each other (incomplete destruction) elements, which depends on the kind of external influence and perfection of materials structure.

  12. Non-destructive and destructive examination of the retired North Anna 2 Reactor Pressure Vessel Head

    International Nuclear Information System (INIS)

    Ahluwalia, Kawaljit; Barnes, Robert; Rao, Gutti; Cattant, Francois; Peat, Noel

    2006-09-01

    Stress corrosion cracking of Alloy 600 and nickel-based weld materials has been the single biggest challenge facing the PWR industry. A fundamental and thorough knowledge was needed to properly explain this phenomenon and develop appropriate mitigation strategies. Non Destructive Examination (NDE) of the North Anna Unit 2 Reactor Vessel Head (RVH) during the 2002 fall outage identified widespread crack indications in the Alloy 600 CRDM penetrations and associated Alloy 182 and 82 J-groove attachment welds. When the Utility decided to replace the RVH, a rare opportunity was provided to the industry to undertake in-depth studies of representative defective CRDM penetrations from a retired RVH. Accordingly, the Materials Reliability Program, undertook a two-phase program on the retired North Anna 2 Alloy 600 RVH. The first phase involved selection and removal of six penetrations from the RVH and penetration decontamination, replication and laboratory NDE. The second phase consisted of a detailed destructive examination of penetration number 54. This paper provides a summary of work undertaken during this program. Criteria for selection of penetrations for removal and procedures used in removal of the penetrations are described. Extreme care was undertaken in decontamination of the penetrations to facilitate laboratory NDE. Penetration number 54 was then subjected to destructive examination to establish a correlation between NDE findings (from both field and laboratory inspections) and actual flaws. Additional objectives of the destructive examination included mechanistic assessment of defect formation and investigation of the annulus environment and wastage characterization. Data obtained from these studies is invaluable in validating safety assessment statements by developing the correlation between field NDE and actual defects. In addition, information gathered from non-destructive and destructive examinations is used to assess accuracy of the NDE techniques

  13. Comparative study of destructive and non-destructive methods in the activation analysis of rocks

    International Nuclear Information System (INIS)

    Vasconcellos, M.B.A.

    1978-01-01

    A comparative study between non-destructive thermal neutron activation analysis and activation analysis with radiochemical group separation is made Both methods are applied to the determination of trace elements minor and major elements in rocks. The treatment of the rocks, with special reference to the problems related to grinding and contamination by foreign elements is described. The choice of standards for multielement trace activation analysis is discussed. Two types of computer programs for the evalution of data obtained through Ge-li detector counting are used. All the phases of the destructive and non destructive analysis are described. In the destructive analysis, an adaptation of the group separation scheme developed by Morrison et al for the activation analysis of geological samples is made. The changes introduced make the radiochemical separation simpler and more rapid. Both destructive and non destructive methods are tested by means of the analysis of the United States Geological Survey standard rock AGV-1, which has been analysed by many authors. The same procedure is then applied to some alcaline rocks taken from the apatite mine of Jacupiranga, in the State of Sao Paulo, Brazil. The knowledge of the trace element concentration in these rocks is important for geochemical studies. A detailed study of the possible interferences encountered in the neutron activation analysis of these rocks is made, considering the interferences due to major activities, and to the proximity of the several gamma ray energies of the radioisotopes produced. Finally, the comparative study between the two methods is presented, using statistical tests for the quantitative evalution of results. (Author) [pt

  14. Destruction of Refractory Carbon in Protoplanetary Disks

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Dana E.; Blake, Geoffrey A. [Division of Geological and Planetary Sciences, California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125 (United States); Bergin, Edwin A. [Department of Astronomy, University of Michigan, 1085 S. University, Ann Arbor, MI 48109-1107 (United States); Ciesla, Fred J. [Department of Geophysical Sciences, The University of Chicago, 5734 South Ellis Ave., Chicago, IL 60637 (United States); Visser, Ruud [European Southern Observatory, Karl-Schwarzschild-Str. 2, D-85748, Garching (Germany); Lee, Jeong-Eun [School of Space Research, Kyung Hee University, 1732, Deogyeong-daero, Giheung-gu, Yongin-si, Gyeonggi-do 17104 (Korea, Republic of)

    2017-08-10

    The Earth and other rocky bodies in the inner solar system contain significantly less carbon than the primordial materials that seeded their formation. These carbon-poor objects include the parent bodies of primitive meteorites, suggesting that at least one process responsible for solid-phase carbon depletion was active prior to the early stages of planet formation. Potential mechanisms include the erosion of carbonaceous materials by photons or atomic oxygen in the surface layers of the protoplanetary disk. Under photochemically generated favorable conditions, these reactions can deplete the near-surface abundance of carbon grains and polycyclic aromatic hydrocarbons by several orders of magnitude on short timescales relative to the lifetime of the disk out to radii of ∼20–100+ au from the central star depending on the form of refractory carbon present. Due to the reliance of destruction mechanisms on a high influx of photons, the extent of refractory carbon depletion is quite sensitive to the disk’s internal radiation field. Dust transport within the disk is required to affect the composition of the midplane. In our current model of a passive, constant- α disk, where α = 0.01, carbon grains can be turbulently lofted into the destructive surface layers and depleted out to radii of ∼3–10 au for 0.1–1 μ m grains. Smaller grains can be cleared out of the planet-forming region completely. Destruction may be more effective in an actively accreting disk or when considering individual grain trajectories in non-idealized disks.

  15. Neutrophil-Derived MMP-8 Drives AMPK-Dependent Matrix Destruction in Human Pulmonary Tuberculosis

    Science.gov (United States)

    Ong, Catherine W. M.; Elkington, Paul T.; Brilha, Sara; Ugarte-Gil, Cesar; Tome-Esteban, Maite T.; Tezera, Liku B.; Pabisiak, Przemyslaw J.; Moores, Rachel C.; Sathyamoorthy, Tarangini; Patel, Vimal; Gilman, Robert H.; Porter, Joanna C.; Friedland, Jon S.

    2015-01-01

    Pulmonary cavities, the hallmark of tuberculosis (TB), are characterized by high mycobacterial load and perpetuate the spread of M. tuberculosis. The mechanism of matrix destruction resulting in cavitation is not well defined. Neutrophils are emerging as key mediators of TB immunopathology and their influx are associated with poor outcomes. We investigated neutrophil-dependent mechanisms involved in TB-associated matrix destruction using a cellular model, a cohort of 108 patients, and in separate patient lung biopsies. Neutrophil-derived NF-kB-dependent matrix metalloproteinase-8 (MMP-8) secretion was up-regulated in TB and caused matrix destruction both in vitro and in respiratory samples of TB patients. Collagen destruction induced by TB infection was abolished by doxycycline, a licensed MMP inhibitor. Neutrophil extracellular traps (NETs) contain MMP-8 and are increased in samples from TB patients. Neutrophils lined the circumference of human pulmonary TB cavities and sputum MMP-8 concentrations reflected TB radiological and clinical disease severity. AMPK, a central regulator of catabolism, drove neutrophil MMP-8 secretion and neutrophils from AMPK-deficient patients secrete lower MMP-8 concentrations. AMPK-expressing neutrophils are present in human TB lung biopsies with phospho-AMPK detected in nuclei. These data demonstrate that neutrophil-derived MMP-8 has a key role in the immunopathology of TB and is a potential target for host-directed therapy in this infectious disease. PMID:25996154

  16. Neutrophil-Derived MMP-8 Drives AMPK-Dependent Matrix Destruction in Human Pulmonary Tuberculosis.

    Science.gov (United States)

    Ong, Catherine W M; Elkington, Paul T; Brilha, Sara; Ugarte-Gil, Cesar; Tome-Esteban, Maite T; Tezera, Liku B; Pabisiak, Przemyslaw J; Moores, Rachel C; Sathyamoorthy, Tarangini; Patel, Vimal; Gilman, Robert H; Porter, Joanna C; Friedland, Jon S

    2015-05-01

    Pulmonary cavities, the hallmark of tuberculosis (TB), are characterized by high mycobacterial load and perpetuate the spread of M. tuberculosis. The mechanism of matrix destruction resulting in cavitation is not well defined. Neutrophils are emerging as key mediators of TB immunopathology and their influx are associated with poor outcomes. We investigated neutrophil-dependent mechanisms involved in TB-associated matrix destruction using a cellular model, a cohort of 108 patients, and in separate patient lung biopsies. Neutrophil-derived NF-kB-dependent matrix metalloproteinase-8 (MMP-8) secretion was up-regulated in TB and caused matrix destruction both in vitro and in respiratory samples of TB patients. Collagen destruction induced by TB infection was abolished by doxycycline, a licensed MMP inhibitor. Neutrophil extracellular traps (NETs) contain MMP-8 and are increased in samples from TB patients. Neutrophils lined the circumference of human pulmonary TB cavities and sputum MMP-8 concentrations reflected TB radiological and clinical disease severity. AMPK, a central regulator of catabolism, drove neutrophil MMP-8 secretion and neutrophils from AMPK-deficient patients secrete lower MMP-8 concentrations. AMPK-expressing neutrophils are present in human TB lung biopsies with phospho-AMPK detected in nuclei. These data demonstrate that neutrophil-derived MMP-8 has a key role in the immunopathology of TB and is a potential target for host-directed therapy in this infectious disease.

  17. Radioisotopes in non-destructive testing

    International Nuclear Information System (INIS)

    Domanus, J.C.

    1976-12-01

    After defining nondestructive testing (NDT) and comparing this concept with destructive testing, a short description is given of NDT methods other than radiologic. The basic concepts of radiologic methods are discussed and the principles of radiography are explained. Radiation sources and gamma radiography machines are next reviewed and radiographic inspection of weldings and castings is described. A brief description is given of the radiographic darkroom and accessories. Other radioisotope methods, such as neutron radiography, are shortly reviewed. Cost estimations for radioisotopic equipment conclude the report. (author)

  18. Safeguards and Non-destructive Assay

    International Nuclear Information System (INIS)

    Carchon, R.; Bruggeman, M.

    2001-01-01

    SCK-CEN's programme on safeguards and non-destructive assay includes: (1) various activities to assure nuclear materials accountancy; (2) contributes to the implementation of Integrated Safeguards measures in Belgium and to assist the IAEA through the Belgian Support Programme; (3) renders services to internal and external customers in the field of safeguards; (4) improves passive neutron coincidence counting techniques for waste assay and safeguards verification measurements by R and D on correlation algorithms implemented via software or dedicated hardware; (5) improves gamma assay techniques for waste assay by implementing advanced scanning techniques and different correlation algorithms; and (6) develops numerical calibration techniques. Major achievements in these areas in 2000 are reported

  19. Non-destructive testing: significant facts

    International Nuclear Information System (INIS)

    Espejo, Hector; Ruch, Marta C.

    2006-01-01

    In the last fifty years different organisations, both public and private, have been assigned to the mission of introducing into the country the most relevant aspects of the modern technological discipline 'Non Destructive Testing' (NDT) through a manifold of activities, such as training and education, research, development, technical assistance and services, personnel qualification/certification and standardisation. A review is given of the significant facts in this process, in which the Argentine Atomic Energy Commission, CNEA, played a leading part, a balance of the accomplishments is made and a forecast of the future of the activity is sketched. (author) [es

  20. Ionizing radiations for non-destructive evaluation

    International Nuclear Information System (INIS)

    Raj, Baldev; Venkataraman, B.

    1989-01-01

    A state of the art of major non-destructive testing (NDT) techniques based on ionising radiations is presented. These techniques are broadly classified into three categories, namely, radiography, radiation gaging and analytical applications. The basic principles behind each method are explained and salient features of each technique which make it suitable for a particular task are described. Several illustrative applications drawn from the nuclear industry are given. The monograph is intended to serve as an introductory guide to scientist and engineers engaged in NDT activities. (M.G.B.). 32 refs., 13 figs., 5 tabs

  1. Destructive hydrogenation of carbonaceous material, etc

    Energy Technology Data Exchange (ETDEWEB)

    1938-07-30

    A process is described for the destructive hydrogenation of solid distillable carbonaceous material, consisting of mixing the raw material in a paste by means of a mixture practically free from asphalt, from an oil obtained initially from the products coming out of the reaction space as vapor, particularly heavy oil, and oils obtained by pushing just to the state of pitch or coke the distillation of all the products which come out of the reaction space in any state but the vapor and which restrain some of the raw material intact and part of the products.

  2. Fingerprint extraction from interference destruction terahertz spectrum.

    Science.gov (United States)

    Xiong, Wei; Shen, Jingling

    2010-10-11

    In this paper, periodic peaks in a terahertz absorption spectrum are confirmed to be induced from interference effects. Theoretically, we explained the periodic peaks and calculated the locations of them. Accordingly, a technique was suggested, with which the interference peaks in a terahertz spectrum can be eliminated and therefore a real terahertz absorption spectrum can be obtained. Experimentally, a sample, Methamphetamine, was investigated and its terahertz fingerprint was successfully extracted from its interference destruction spectrum. This technique is useful in getting samples' terahertz fingerprint spectra, and furthermore provides a fast nondestructive testing method using a large size terahertz beam to identify materials.

  3. Non-Destructive Testing for Concrete Structure

    International Nuclear Information System (INIS)

    Tengku Sarah Tengku Amran; Noor Azreen Masenwat; Mohamad Pauzi Ismail

    2015-01-01

    Nondestructive testing (NDT) is a technique to determine the integrity of a material, component or structure. It is essential in the inspection of alteration, repair and new construction in the building industry. There are a number of non-destructive testing techniques that can be applied to determine the integrity of concrete in a completed structure. Each has its own advantages and limitations. For concrete, these problems relate to strength, cracking, dimensions, delamination, and inhomogeneities. NDT is reasonably good and reliable tool to measure the property of concrete which also gives the fair indication of the compressive strength development. This paper discussed the concrete inspection using combined methods of NDT. (author)

  4. Optimization of low-frequency low-intensity ultrasound-mediated microvessel disruption on prostate cancer xenografts in nude mice using an orthogonal experimental design.

    Science.gov (United States)

    Yang, Y U; Bai, Wenkun; Chen, Yini; Lin, Yanduan; Hu, Bing

    2015-11-01

    The present study aimed to provide a complete exploration of the effect of sound intensity, frequency, duty cycle, microbubble volume and irradiation time on low-frequency low-intensity ultrasound (US)-mediated microvessel disruption, and to identify an optimal combination of the five factors that maximize the blockage effect. An orthogonal experimental design approach was used. Enhanced US imaging and acoustic quantification were performed to assess tumor blood perfusion. In the confirmatory test, in addition to acoustic quantification, the specimens of the tumor were stained with hematoxylin and eosin and observed using light microscopy. The results revealed that sound intensity, frequency, duty cycle, microbubble volume and irradiation time had a significant effect on the average peak intensity (API). The extent of the impact of the variables on the API was in the following order: Sound intensity; frequency; duty cycle; microbubble volume; and irradiation time. The optimum conditions were found to be as follows: Sound intensity, 1.00 W/cm 2 ; frequency, 20 Hz; duty cycle, 40%; microbubble volume, 0.20 ml; and irradiation time, 3 min. In the confirmatory test, the API was 19.97±2.66 immediately subsequent to treatment, and histological examination revealed signs of tumor blood vessel injury in the optimum parameter combination group. In conclusion, the Taguchi L 18 (3) 6 orthogonal array design was successfully applied for determining the optimal parameter combination of API following treatment. Under the optimum orthogonal design condition, a minimum API of 19.97±2.66 subsequent to low-frequency and low-intensity mediated blood perfusion blockage was obtained.

  5. On the dynamics of StemBells: Microbubble-conjugated stem cells for ultrasound-controlled delivery

    Science.gov (United States)

    Kokhuis, Tom J. A.; Naaijkens, Benno A.; Juffermans, Lynda J. M.; Kamp, Otto; van der Steen, Antonius F. W.; Versluis, Michel; de Jong, Nico

    2017-07-01

    The use of stem cells for regenerative tissue repair is promising but hampered by the low number of cells delivered to the site of injury. To increase the delivery, we propose a technique in which stem cells are linked to functionalized microbubbles, creating echogenic complex dubbed StemBells. StemBells are highly susceptible to acoustic radiation force which can be employed after injection to push the StemBells locally to the treatment site. To optimally benefit from the delivery technique, a thorough characterization of the dynamics of StemBells during ultrasound exposure is needed. Using high-speed optical imaging, we study the dynamics of StemBells as a function of the applied frequency from which resonance curves were constructed. A theoretical model, based on a modified Rayleigh-Plesset type equation, captured the experimental resonance characteristics and radial dynamics in detail.

  6. High-Frequency Fiber-Optic Ultrasonic Sensor Using Air Micro-Bubble for Imaging of Seismic Physical Models.

    Science.gov (United States)

    Gang, Tingting; Hu, Manli; Rong, Qiangzhou; Qiao, Xueguang; Liang, Lei; Liu, Nan; Tong, Rongxin; Liu, Xiaobo; Bian, Ce

    2016-12-14

    A micro-fiber-optic Fabry-Perot interferometer (FPI) is proposed and demonstrated experimentally for ultrasonic imaging of seismic physical models. The device consists of a micro-bubble followed by the end of a single-mode fiber (SMF). The micro-structure is formed by the discharging operation on a short segment of hollow-core fiber (HCF) that is spliced to the SMF. This micro FPI is sensitive to ultrasonic waves (UWs), especially to the high-frequency (up to 10 MHz) UW, thanks to its ultra-thin cavity wall and micro-diameter. A side-band filter technology is employed for the UW interrogation, and then the high signal-to-noise ratio (SNR) UW signal is achieved. Eventually the sensor is used for lateral imaging of the physical model by scanning UW detection and two-dimensional signal reconstruction.

  7. Application of a drug delivery system using ultrasound and nano/microbubbles for anti-angiogenic therapy

    International Nuclear Information System (INIS)

    Horie, Sachiko; Kodama, Tetsuya; Sato, Yasushi

    2017-01-01

    The drug delivery system using ultrasound and nano/microbubbles is a molecular delivery approach using the mechanism of sonoporation. With sonoporation, an endothelium-derived negative-feedback regulator of angiogenesis, Vasohibin-1 (VASH1), was introduced specifically into tumor vessels. We found VASH1 in tumor vessels induce normalization of tumor vessels and inhibited tumor growth. A recent topic regarding tumor angiogenesis is vascular normalization. Tumor vessels are abnormal or immature that cause hyperpermeability and impaired blood flow. Tumor vascular normalization improves blood flow and tissue hypoxia, which increase the effectiveness of chemotherapy and radiotherapy and reduce tumor cell malignancy. In this review, application of drug delivery system using ultrasound for an anti-angiogenic therapy, a tumor vessel normalization therapy to treat cancer, is summarized. (author)

  8. Optical Microbubble Resonators with High Refractive Index Inner Coating for Bio-Sensing Applications: An Analytical Approach

    Directory of Open Access Journals (Sweden)

    Andrea Barucci

    2016-11-01

    Full Text Available The design of Whispering Gallery Mode Resonators (WGMRs used as an optical transducer for biosensing represents the first and crucial step towards the optimization of the final device performance in terms of sensitivity and Limit of Detection (LoD. Here, we propose an analytical method for the design of an optical microbubble resonator (OMBR-based biosensor. In order to enhance the OMBR sensing performance, we consider a polymeric layer of high refractive index as an inner coating for the OMBR. The effect of this layer and other optical/geometrical parameters on the mode field distribution, sensitivity and LoD of the OMBR is assessed and discussed, both for transverse electric (TE and transverse magnetic (TM polarization. The obtained results do provide physical insights for the development of OMBR-based biosensor.

  9. Pretest Score for Predicting Microbubble Contrast Agent Use in Stress Echocardiography: A Method to Increase Efficiency in the Echo Laboratory

    Directory of Open Access Journals (Sweden)

    Mathieu Bernier

    2009-01-01

    contrast. Logistic regression models were used to evaluate the association between individual characteristics and contrast use. An 11-point score was derived from the significant characteristics. Results. Variables associated with microbubble use were age, sex, smoking, presence of multiple risk factors, bodymass index (BMI, referral for dobutamine stress echocardiography, history of coronary artery disease, and abnormal baseline electrocardiogram. All variables except BMI were given a score of 1 if present and 0 if absent; BMI was given a score of 0 to 4 according to its value. An increased score was directly proportional to increased likelihood of contrast use. The score cutoff value to optimize sensitivity and specificity was 5. Conclusions. A pretest score can be computed from information available before imaging. It may facilitate contrast agent use through early identification of patients who are likely to benefit from improved endocardial border definition.

  10. Optical Spring Effect in Micro-Bubble Resonators and Its Application for the Effective Mass Measurement of Optomechanical Resonant Mode

    Directory of Open Access Journals (Sweden)

    Zhenmin Chen

    2017-09-01

    Full Text Available In this work, we present a novel approach for obtaining the effective mass of mechanical vibration mode in micro-bubble resonators (MBRs. To be specific, the effective mass is deduced from the measurement of optical spring effect (OSE in MBRs. This approach is demonstrated and applied to analyze the effective mass of hollow MBRs and liquid-filled MBRs, respectively. It is found that the liquid-filled MBRs has significantly stronger OSE and a less effective mass than hollow MBRs, both of the extraordinary behaviors can be beneficial for applications such as mass sensing. Larger OSE from higher order harmonics of the mechanical modes is also observed. Our work paves a way towards the developing of OSE-based high sensitive mass sensor in MBRs.

  11. Optical Spring Effect in Micro-Bubble Resonators and Its Application for the Effective Mass Measurement of Optomechanical Resonant Mode.

    Science.gov (United States)

    Chen, Zhenmin; Wu, Xiang; Liu, Liying; Xu, Lei

    2017-09-30

    In this work, we present a novel approach for obtaining the effective mass of mechanical vibration mode in micro-bubble resonators (MBRs). To be specific, the effective mass is deduced from the measurement of optical spring effect (OSE) in MBRs. This approach is demonstrated and applied to analyze the effective mass of hollow MBRs and liquid-filled MBRs, respectively. It is found that the liquid-filled MBRs has significantly stronger OSE and a less effective mass than hollow MBRs, both of the extraordinary behaviors can be beneficial for applications such as mass sensing. Larger OSE from higher order harmonics of the mechanical modes is also observed. Our work paves a way towards the developing of OSE-based high sensitive mass sensor in MBRs.

  12. Rapidly Destructive Inflammatory Arthritis of the Hip

    Directory of Open Access Journals (Sweden)

    Jenny Shu

    2014-01-01

    Full Text Available Rapidly destructive coxarthrosis (RDC is a rare syndrome that involves aggressive hip joint destruction within 6–12 months of symptom onset with no single diagnostic laboratory, pathological, or radiographic finding. We report an original case of RDC as an initial presentation of seronegative rheumatoid arthritis (RA in a 57-year-old Caucasian woman presenting with 6 months of progressive right groin pain and no preceding trauma or chronic steroid use. Over 5 months, she was unable to ambulate and plain films showed complete resorption of the right femoral head and erosion of the acetabulum. There were inflammatory features seen on computed tomography (CT and magnetic resonance imaging (MRI. She required a right total hip arthroplasty, but arthritis in other joints showed improvement with triple disease modifying antirheumatic drugs (DMARD therapy and almost complete remission with the addition of adalimumab. We contrast our case of RDC as an initial presentation of RA to 8 RDC case reports of patients with established RA. Furthermore, this case highlights the importance of obtaining serial imaging to evaluate a patient with persistent hip symptoms and rapid functional deterioration.

  13. Non-destructive testing; Examenes no destructivos

    Energy Technology Data Exchange (ETDEWEB)

    Calva, Mauricio; Loske, Achim [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1988-12-31

    The application of non-destructive testing (NDT) in several technical and industrial fields is pointed out, standing out its utilization in the detection of future failures without affecting the examined element. Likewise, the different types of NDTs and their processes, such as x-rays, ultrasoud, magnetic particles, induced currents, penetrating fluids, and optical means, are described. The Non-Destructive Tests Laboratory of the Instituto de Investigaciones Electricas (IIE), plans to create new and more reliable systems independent from the operator`s capacity, to contribute to fulfill the inspection and quality control needs of the generating Mexican power plants. [Espanol] Se senala la aplicacion de los examenes no destructivos (END) a diversos campos tecnicos e industriales, destacando su utilizacion en la deteccion de futuras fallas sin afectar el elemento examinado. Asimismo, se describen los diferentes tipos de END y sus procesos, tales como radiografia, ultrasonido, particulas magneticas, corrientes inducidas, liquidos penetrantes y metodos opticos. El Laboratorio de Pruebas no Destructivas, del Instituto de Investigaciones Electricas (IIE), planea crear sistemas novedosos mas confiables, que no dependan de la capacidad del operador, para contribuir a satisfacer las necesidades de inspeccion y control de calidad que se presentan en las plantas generadoras de energia mexicanas.

  14. Developments in non-destructive beam diagnostics

    International Nuclear Information System (INIS)

    Fraser, J.S.

    1981-01-01

    With the large average beam currents being achieved in accelerators and storage rings, there is an increasing need for non-destructive beam diagnostic devices. For continuous beams, position monitors of the capacitive pick-up type are replaced by resonant devices that respond to the transverse displacement of the beam centroid. Bunch length monitors of the SLAC type using resonant cavities operating in the TM 010 mode can be used for continuous beams. The more detailed information derivable from beam profile scanners requires development of improved non-destructive devices. Profile monitors which scan the visible light produced by high current beams may be more reliable than ones using the residual ionization if the light intensity from gas molecules following nonionizing collisions with beam particles gives a measure of the beam current density independent of the local electron density. The intense Balmer series lines from neutral hydrogen beams have been used successfully to measure beam profiles. At CRNL and at LASL, beam light profile monitors are being developed for high average current accelerators. Three or more projections will be recorded to allow tomographic reconstruction of the two-dimensional beam current density. Light detection is either by intensified Reticons or ISIT vidicons. The use of three or more beam light monitors on a beam transport line will also permit estimates of the transverse emittance to be made through the reconstruction technique

  15. Non-destructive testing; Examenes no destructivos

    Energy Technology Data Exchange (ETDEWEB)

    Calva, Mauricio; Loske, Achim [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1987-12-31

    The application of non-destructive testing (NDT) in several technical and industrial fields is pointed out, standing out its utilization in the detection of future failures without affecting the examined element. Likewise, the different types of NDTs and their processes, such as x-rays, ultrasoud, magnetic particles, induced currents, penetrating fluids, and optical means, are described. The Non-Destructive Tests Laboratory of the Instituto de Investigaciones Electricas (IIE), plans to create new and more reliable systems independent from the operator`s capacity, to contribute to fulfill the inspection and quality control needs of the generating Mexican power plants. [Espanol] Se senala la aplicacion de los examenes no destructivos (END) a diversos campos tecnicos e industriales, destacando su utilizacion en la deteccion de futuras fallas sin afectar el elemento examinado. Asimismo, se describen los diferentes tipos de END y sus procesos, tales como radiografia, ultrasonido, particulas magneticas, corrientes inducidas, liquidos penetrantes y metodos opticos. El Laboratorio de Pruebas no Destructivas, del Instituto de Investigaciones Electricas (IIE), planea crear sistemas novedosos mas confiables, que no dependan de la capacidad del operador, para contribuir a satisfacer las necesidades de inspeccion y control de calidad que se presentan en las plantas generadoras de energia mexicanas.

  16. EFFLUENT TREATMENT FACILITY PEROXIDE DESTRUCTION CATALYST TESTING

    International Nuclear Information System (INIS)

    HALGREN DL

    2008-01-01

    The 200 Area Effluent Treatment Facility (ETF) main treatment train includes the peroxide destruction module (PDM) where the hydrogen peroxide residual from the upstream ultraviolet light/hydrogen peroxide oxidation unit is destroyed. Removal of the residual peroxide is necessary to protect downstream membranes from the strong oxidizer. The main component of the PDM is two reaction vessels utilizing granular activated carbon (GAC) as the reaction media. The PDM experienced a number of operability problems, including frequent plugging, and has not been utilized since the ETF changed to groundwater as the predominant feed. The unit seemed to be underperforming in regards to peroxide removal during the early periods of operation as well. It is anticipated that a functional PDM will be required for wastewater from the vitrification plant and other future streams. An alternate media or methodology needs to be identified to replace the GAC in the PDMs. This series of bench scale tests is to develop information to support an engineering study on the options for replacement of the existing GAC method for peroxide destruction at the ETF. A number of different catalysts will be compared as well as other potential methods such as strong reducing agents. The testing should lead to general conclusions on the viability of different catalysts and identify candidates for further study and evaluation

  17. The partitioning of nanoparticles to endothelium or interstitium during ultrasound-microbubble-targeted delivery depends on peak-negative pressure

    International Nuclear Information System (INIS)

    Hsiang, Y.-H.; Song, J.; Price, R. J.

    2015-01-01

    Patients diagnosed with advanced peripheral arterial disease often face poor prognoses and have limited treatment options. For some patient populations, the therapeutic growth of collateral arteries (i.e. arteriogenesis) that bypass regions affected by vascular disease may become a viable treatment option. Our group and others are developing therapeutic approaches centered on the ability of ultrasound-activated microbubbles to permeabilize skeletal muscle capillaries and facilitate the targeted delivery of pro-arteriogenic growth factor-bearing nanoparticles. The development of such approaches would benefit significantly from a better understanding of how nanoparticle diameter and ultrasound peak-negative pressure affect both total nanoparticle delivery and the partitioning of nanoparticles to endothelial or interstitial compartments. Toward this goal, using Balb/C mice that had undergone unilateral femoral artery ligation, we intra-arterially co-injected nanoparticles (50 and 100 nm) with microbubbles, applied 1 MHz ultrasound to the gracilis adductor muscle at peak-negative pressures of 0.7, 0.55, 0.4, and 0.2 MPa, and analyzed nanoparticle delivery and distribution. As expected, total nanoparticle (50 and 100 nm) delivery increased with increasing peak-negative pressure, with 50 nm nanoparticles exhibiting greater tissue coverage than 100 nm nanoparticles. Of particular interest, increasing peak-negative pressure resulted in increased delivery to the interstitium for both nanoparticle sizes, but had little influence on nanoparticle delivery to the endothelium. Thus, we conclude that alterations to peak-negative pressure may be used to adjust the fraction of nanoparticles delivered to the interstitial compartment. This information will be useful when designing ultrasound protocols for delivering pro-arteriogenic nanoparticles to skeletal muscle

  18. The partitioning of nanoparticles to endothelium or interstitium during ultrasound-microbubble-targeted delivery depends on peak-negative pressure

    Energy Technology Data Exchange (ETDEWEB)

    Hsiang, Y.-H.; Song, J.; Price, R. J., E-mail: rprice@virginia.edu [University of Virginia, Department of Biomedical Engineering (United States)

    2015-08-15

    Patients diagnosed with advanced peripheral arterial disease often face poor prognoses and have limited treatment options. For some patient populations, the therapeutic growth of collateral arteries (i.e. arteriogenesis) that bypass regions affected by vascular disease may become a viable treatment option. Our group and others are developing therapeutic approaches centered on the ability of ultrasound-activated microbubbles to permeabilize skeletal muscle capillaries and facilitate the targeted delivery of pro-arteriogenic growth factor-bearing nanoparticles. The development of such approaches would benefit significantly from a better understanding of how nanoparticle diameter and ultrasound peak-negative pressure affect both total nanoparticle delivery and the partitioning of nanoparticles to endothelial or interstitial compartments. Toward this goal, using Balb/C mice that had undergone unilateral femoral artery ligation, we intra-arterially co-injected nanoparticles (50 and 100 nm) with microbubbles, applied 1 MHz ultrasound to the gracilis adductor muscle at peak-negative pressures of 0.7, 0.55, 0.4, and 0.2 MPa, and analyzed nanoparticle delivery and distribution. As expected, total nanoparticle (50 and 100 nm) delivery increased with increasing peak-negative pressure, with 50 nm nanoparticles exhibiting greater tissue coverage than 100 nm nanoparticles. Of particular interest, increasing peak-negative pressure resulted in increased delivery to the interstitium for both nanoparticle sizes, but had little influence on nanoparticle delivery to the endothelium. Thus, we conclude that alterations to peak-negative pressure may be used to adjust the fraction of nanoparticles delivered to the interstitial compartment. This information will be useful when designing ultrasound protocols for delivering pro-arteriogenic nanoparticles to skeletal muscle.

  19. Changes in tumor vascularity precede microbubble contrast accumulation deficit in the process of dedifferentiation of hepatocellular carcinoma

    International Nuclear Information System (INIS)

    Maruyama, Hitoshi; Takahashi, Masanori; Ishibashi, Hiroyuki; Okabe, Shinichiro; Yoshikawa, Masaharu; Yokosuka, Osamu

    2010-01-01

    Purpose: To elucidate the changes in tumor vascularity and microbubble accumulation on contrast-enhanced sonograms, in relation to the dedifferentiation of hepatocellular carcinoma (HCC). Materials and methods: This prospective study enrolled 10 patients with histologically proven HCC (14.4-39.0 mm, 26.1 ± 7.4) showing nodule-in-nodule appearance upon contrast-enhanced computed tomography. Contrast-enhanced ultrasound was performed by harmonic imaging under a low mechanical index (0.22-0.25) during the vascular phase (agent injection to 1 min) and late phase (15 min) following the injection of Sonazoid TM (0.0075 ml/kg). Contrast enhancement in the inner and outer nodules was assessed in comparison with that in adjacent liver parenchyma as hyper-, iso-, or hypo-enhanced. Results: Vascular-phase enhancement of all 10 inner nodules was hyper-enhanced, and that of outer nodules was hyper-enhanced in 3, iso-enhanced in 2, and hypo-enhanced in 5. Late-phase enhancement of inner nodules was hypo-enhanced in 8 and iso-enhanced in 2. Furthermore, late-phase enhancement of outer nodules was iso-enhanced in the 7 lesions that showed iso- or hypo-enhancement in the vascular phase, and hypo-enhanced in the 3 with hyper-enhancement in the vascular phase. Late-phase hypo-enhancement was significantly more frequent in the nodules showing early-phase hyper-enhancement (11/13) than in the nodules showing early-phase iso- or hypo-enhancement (0/7) in both the inner and outer nodules. Conclusion: Dedifferentiation of HCC may be accompanied by changes in tumor vascularity prior to a reduction in microbubble accumulation. Observation of the vascular phase may be more useful than late-phase imaging for the early recognition of HCC dedifferentiation when using contrast-enhanced ultrasound with Sonazoid.

  20. Intercultural Mediation

    OpenAIRE

    Dragos Marian Radulescu; Denisa Mitrut

    2012-01-01

    The Intercultural Mediator facilitates exchanges between people of different socio-cultural backgrounds and acts as a bridge between immigrants and national and local associations, health organizations, services and offices in order to foster integration of every single individual. As the use mediation increases, mediators are more likely to be involved in cross-cultural mediation, but only the best mediators have the opportunity to mediate cross border business disputes or international poli...

  1. Dismantlement and destruction of chemical, nuclear and conventional weapons

    International Nuclear Information System (INIS)

    Schulte, N.T.

    1997-01-01

    The safe destruction and dismantling of chemical, nuclear and conventional weapons is of fundamental importance to the security of all countries represented in this volume. Expertise in the field is not confined to one country or organisation: all can benefit from each other. There is an ever present danger of proliferation of weapons of mass destruction: approximately two dozen countries have ongoing programmes to develop or acquire such weapons, and many are also gaining the capability to build air-surface delivery systems. But much can be done to prevent proliferation by reducing leakage of materials and know-how and by solving the problems of the destruction of surplus weapons systems, which has now come to be a key issue. In 13 sessions of the workshop attention was paid to (1) Dismantlement and Destruction of Chemical, Nuclear and Conventional Weapons; (2) Status of Implementation of Arms Control Treaties and Voluntary Commitments; (3) National Perspectives on Cooperation in Disarmament; (4) Stocktaking of National and Bilateral Disposal/Destruction Programmes: Chemical Weapons; (5) Stocktaking of National and Bilateral Disposal/Destruction Programmes: Nuclear Weapons; (6) Stocktaking of National and Bilateral Disposal/Destruction Programmes: Conventional Weapons. Session; (7) Experience with Currently Employed Chemical Destruction Technologies; (8) Alternative Chemical Destruction Technologies; (9) Deactivation, Dismantlement and Destruction of Delivery Systems and Infrastructure for Nuclear Weapons; (10) Storage, Safeguarding and Disposition of Fissile Materials; (11) Technologies for Conversion and Civil Use of Demilitarized Materials; (12) International Organizations; and (13) Environmental Challenges Posed by Chemical and Nuclear Disarmament

  2. A comparison between destructive and non-destructive techniques in determining coating thickness

    Science.gov (United States)

    Haider, F. I.; Suryanto; Ani, M. H.; Mahmood, M. H.

    2018-01-01

    Measuring coating thickness is an important part in research works related to coating applications. In general, techniques for measuring coating thickness may be divided into destructive and non-destructive methods which are commonly used depending on the applications. The objective of this study is to compare two methods measuring the coating thickness of electroplating copper coating on the austenitic stainless-steel substrate. The electroplating was carried out in a solution containing 200 g/L CuSO4, 100 g/L H2SO4 at room temperature and current of 40mA/cm2 during 20, 40, 60, 80 and 100 mins as coating periods. And the coating thickness was measured by two methods, cross sectional analysis as a destructive technique and weight gain as a non-destructive technique. The results show that at 20 mins coating time interval, the thickness measured by cross sectional method was 16.67 μm and by weight gain method was 17.37 μm, with difference of 0.7 μm and percentage error of 4.11%. This error increased to 5.27% at 100mins time interval, where the values of the thickness measured by cross sectional and weight gain were 86.33 μm and 81.9 μm respectively, and the difference was 4.43 μm. Moreover, though the weight gain method is fast and gives the indication for the termination of a coating process, information regarding the uniformity, porosity and the presence of cracks cannot be obtained. On the other hand, determining the coating thickness using destructive method will damage the sample.

  3. Mechanisms of immune red cell destruction, and red cell compatibility testing

    International Nuclear Information System (INIS)

    Garratty, G.

    1983-01-01

    The immune destruction of red cells can occur as a complement-mediated intravascular process, or extravascularly, where the red cells are destroyed by macrophages following interaction with cell-bound IgG1, IgG3, and/or C3b. Many of the factors that affect this in vivo destruction are not taken into account during in vitro pretransfusion compatibility testing. At present, even by use of more elaborate tests, it is difficult to accurately predict the fate of a transfused unit of blood. By using some simple information, such as antibody specificity and thermal range, it is sometimes possible to predict the outcome of transfusing a unit of blood that is incompatible in vitro. At other times it may be necessary to utilize 51 Cr-labeled red cells to determine the risk of transfusing such units. Because of the paucity of reported clinical correlations, macrophage/monocyte monolayer assays are of little practical value at present

  4. Photocatalysts: ambient temperature destruction of VOCs

    Energy Technology Data Exchange (ETDEWEB)

    Miller, R [IT Corp., Oak Ridge, TN (United States)

    1994-12-31

    Photocatalysis was a failure as a solar energy driven organic synthesis technique, but as this study indicates, it has undergone a renaissance as a promising treatment method for volatile organic compounds (VOCs) in air streams. Photocatalytic oxidation (PCO) relies upon the ability of certain semiconductors to be stimulated by UV radiation. UV light excites valence band electrons in the semiconductor catalyst to jump to a conductance band leaving holes in the valence band. The electrons and holes can react with compounds such as organic contaminants present in an air stream. Hallmarks of the technology include rapid destruction kinetics for many VOCs at ambient temperature and efficient use energy in the form of UV-A photons. Studies clearly indicate that PCO is competitive on capital cost and offers significant operating cost savings on selected applications. 6 refs., 3 tabs., 2 figs.

  5. Photocatalysts: ambient temperature destruction of VOCs

    International Nuclear Information System (INIS)

    Miller, R.

    1994-01-01

    Photocatalysis was a failure as a solar energy driven organic synthesis technique, but as this study indicates, it has undergone a renaissance as a promising treatment method for volatile organic compounds (VOCs) in air streams. Photocatalytic oxidation (PCO) relies upon the ability of certain semiconductors to be stimulated by UV radiation. UV light excites valence band electrons in the semiconductor catalyst to jump to a conductance band leaving holes in the valence band. The electrons and holes can react with compounds such as organic contaminants present in an air stream. Hallmarks of the technology include rapid destruction kinetics for many VOCs at ambient temperature and efficient use energy in the form of UV-A photons. Studies clearly indicate that PCO is competitive on capital cost and offers significant operating cost savings on selected applications. 6 refs., 3 tabs., 2 figs

  6. On the destruction of musical instruments

    Directory of Open Access Journals (Sweden)

    Matteo Ravasio

    2016-08-01

    Full Text Available In this article, I aim to provide an account of the peculiar reasons that motivate our negative reaction whenever we see musical instruments being mistreated and destroyed. Stephen Davies has suggested that this happens because we seem to treat musical instruments as we treat human beings, at least in some relevant respects. I argue in favour of a different explanation, one that is based on the nature of music as an art form. The main idea behind my account is that musical instruments are not mere tools for the production of art; rather, they are involved in an essential way in artistic appreciation of music. This fact not only grounds our negative reaction to their mistreatment and destruction but also has a normative force that is lacked by the account proposed by Davies.

  7. Destructive hydrogenation of carbonaceous materials, etc

    Energy Technology Data Exchange (ETDEWEB)

    1938-02-15

    A process is described for the destructive hydrogenation continuously of solid and infusible carbonaceous substances, consisting of heating the charge to the same temperature as the added hydrogen, under a pressure essentially equal to that of the reaction, from the first to at least 300/sup 0/C, but not more than 440/sup 0/C, while passing the heated charge through a zone the contents of which are equal to about 20 per cent to 40 per cent of that of the reaction space, maintaining the charge for a certain time at the temperature without sensible change in the pressure, then reheating the charge to at least the temperature to prime the reaction and finally to introduce the charge into the reaction space.

  8. Non destructive testing in amusement park

    International Nuclear Information System (INIS)

    Dominguez Marrero, Humberto; Hernandez Torres, Debora; Sendoya Puente, Felix; Herrera Palma, Victoria; Suarez Guerra, Yarelis; Moreno Hernandez, Eduardo; Lopez Hernandez, Pedro

    2009-01-01

    In 2006 began the installation of Chinese amusement parks at several places in Havana City. Structural security is one of the principal tasks that should be done, since the beginning of the services of these installations. The use on Non Destructive Testing Techniques (NDT), has to be development and implemented in order to avoid the possibility of failure during services with a consequence threat to safety for the public presented. In this work it is shown the results of application of NDT techniques and recommendations for the quality control of the different welds and mechanical components presented. Techniques as Visual Examination, Liquid Penetrant and Ultrasonic have been used for these purposes in order to obtain a structural diagnostic in the amusement parks. There are also exposed the use and implementation of international recommendations and Standards, which are very rigorous in its applications for the case of recreation industry. This is a consequence to its social service fundamentally to children and teenage people. (Author)

  9. Cosmological simulation with dust formation and destruction

    Science.gov (United States)

    Aoyama, Shohei; Hou, Kuan-Chou; Hirashita, Hiroyuki; Nagamine, Kentaro; Shimizu, Ikkoh

    2018-06-01

    To investigate the evolution of dust in a cosmological volume, we perform hydrodynamic simulations, in which the enrichment of metals and dust is treated self-consistently with star formation and stellar feedback. We consider dust evolution driven by dust production in stellar ejecta, dust destruction by sputtering, grain growth by accretion and coagulation, and grain disruption by shattering, and treat small and large grains separately to trace the grain size distribution. After confirming that our model nicely reproduces the observed relation between dust-to-gas ratio and metallicity for nearby galaxies, we concentrate on the dust abundance over the cosmological volume in this paper. The comoving dust mass density has a peak at redshift z ˜ 1-2, coincident with the observationally suggested dustiest epoch in the Universe. In the local Universe, roughly 10 per cent of the dust is contained in the intergalactic medium (IGM), where only 1/3-1/4 of the dust survives against dust destruction by sputtering. We also show that the dust mass function is roughly reproduced at ≲ 108 M⊙, while the massive end still has a discrepancy, which indicates the necessity of stronger feedback in massive galaxies. In addition, our model broadly reproduces the observed radial profile of dust surface density in the circum-galactic medium (CGM). While our model satisfies the observational constraints for the dust extinction on cosmological scales, it predicts that the dust in the CGM and IGM is dominated by large (>0.03 μm) grains, which is in tension with the steep reddening curves observed in the CGM.

  10. Constructive Deviance, Destructive Deviance and Personality: How do they interrelate?

    OpenAIRE

    Bodankin, Moran; Tziner, Aharon

    2009-01-01

    In recent years deviant behavior in organizations has drawn increasing attention. However, surprisingly little research has focused on constructive rather than destructive deviance. In an attempt to bridge this gap, the present study investigated both constructive and destructive deviance at work and their relationship to employee personality. Using 89 hitech employees, constructive and destructive (interpersonal and organizational) deviance were regressed on the big-five factors of personali...

  11. Aesthetics of destruction in contemporary science fiction cinema

    OpenAIRE

    Warton, John Phillips

    2015-01-01

    Mass destruction imagery within the science fiction film genre is not a new cinematic development. However, a swell of destruction-centred films has emerged since the proliferation of digital technologies and computer-generated imagery that reflect concerns that extend beyond notions of spectacle. Through illusionistic realism techniques, the aesthetics of mass destruction imagery within science fiction cinema can be seen as appropriating the implied veracity of other film trad...

  12. Influence of ultrasound power on acoustic streaming and micro-bubbles formations in a low frequency sono-reactor: mathematical and 3D computational simulation.

    Science.gov (United States)

    Sajjadi, Baharak; Raman, Abdul Aziz Abdul; Ibrahim, Shaliza

    2015-05-01

    This paper aims at investigating the influence of ultrasound power amplitude on liquid behaviour in a low-frequency (24 kHz) sono-reactor. Three types of analysis were employed: (i) mechanical analysis of micro-bubbles formation and their activities/characteristics using mathematical modelling. (ii) Numerical analysis of acoustic streaming, fluid flow pattern, volume fraction of micro-bubbles and turbulence using 3D CFD simulation. (iii) Practical analysis of fluid flow pattern and acoustic streaming under ultrasound irradiation using Particle Image Velocimetry (PIV). In mathematical modelling, a lone micro bubble generated under power ultrasound irradiation was mechanistically analysed. Its characteristics were illustrated as a function of bubble radius, internal temperature and pressure (hot spot conditions) and oscillation (pulsation) velocity. The results showed that ultrasound power significantly affected the conditions of hotspots and bubbles oscillation velocity. From the CFD results, it was observed that the total volume of the micro-bubbles increased by about 4.95% with each 100 W-increase in power amplitude. Furthermore, velocity of acoustic streaming increased from 29 to 119 cm/s as power increased, which was in good agreement with the PIV analysis. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Temporal effect of inertial cavitation with and without microbubbles on surface deformation of agarose S gel in the presence of 1-MHz focused ultrasound.

    Science.gov (United States)

    Tomita, Y; Matsuura, T; Kodama, T

    2015-01-01

    Sonoporation has the potential to deliver extraneous molecules into a target tissue non-invasively. There have been numerous investigations of cell membrane permeabilization induced by microbubbles, but very few studies have been carried out to investigate sonoporation by inertial cavitation, especially from a temporal perspective. In the present paper, we show the temporal variations in nano/micro-pit formations following the collapse of inertial cavitation bubbles, with and without Sonazoid® microbubbles. Using agarose S gel as a target material, erosion experiments were conducted in the presence of 1-MHz focused ultrasound applied for various exposure times, Tex (0.002-60 s). Conventional microscopy was used to measure temporal variations in micrometer-scale pit numbers, and atomic force microscopy utilized to detect surface roughness on a nanometer scale. The results demonstrated that nanometer-scale erosion was predominantly caused by Sonazoid® microbubbles and C4F10 gas bubbles for 0.002 scavitation bubbles such as C4F10 gas bubbles and vapor bubbles, increased exponentially with increasing Tex in the range 0.1 scavitation-induced sonoporation can produce various pore sizes in membranes, enabling the delivery of external molecules of differing sizes into cells or tissues. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. DESTRUCTION OF INTERSTELLAR DUST IN EVOLVING SUPERNOVA REMNANT SHOCK WAVES

    International Nuclear Information System (INIS)

    Slavin, Jonathan D.; Dwek, Eli; Jones, Anthony P.

    2015-01-01

    Supernova generated shock waves are responsible for most of the destruction of dust grains in the interstellar medium (ISM). Calculations of the dust destruction timescale have so far been carried out using plane parallel steady shocks, however, that approximation breaks down when the destruction timescale becomes longer than that for the evolution of the supernova remnant (SNR) shock. In this paper we present new calculations of grain destruction in evolving, radiative SNRs. To facilitate comparison with the previous study by Jones et al., we adopt the same dust properties as in that paper. We find that the efficiencies of grain destruction are most divergent from those for a steady shock when the thermal history of a shocked gas parcel in the SNR differs significantly from that behind a steady shock. This occurs in shocks with velocities ≳200 km s −1 for which the remnant is just beginning to go radiative. Assuming SNRs evolve in a warm phase dominated ISM, we find dust destruction timescales are increased by a factor of ∼2 compared to those of Jones et al., who assumed a hot gas dominated ISM. Recent estimates of supernova rates and ISM mass lead to another factor of ∼3 increase in the destruction timescales, resulting in a silicate grain destruction timescale of ∼2–3 Gyr. These increases, while not able to resolve the problem of the discrepant timescales for silicate grain destruction and creation, are an important step toward understanding the origin and evolution of dust in the ISM

  15. The forms of destructive behavior in the workplace

    Directory of Open Access Journals (Sweden)

    D A Narozhnaia

    2015-12-01

    Full Text Available Personnel have become a key resource of organizations in the contemporary society for the way personnel fulfills its work functions can provide important advantages in the competitive market. However, despite the fact that organizations’ management pays great attention to the development of the constructive forms of work behavior, various forms of destructive behavior in the workplace are quite widespread nowadays. The author uses the concept “destructive labor behavior” to denote such observable actions of employees that hinder achieving organizations’ aims and entail negative consequences. The article analyzes relationships between concepts “destructive labor behavior”, “social behavior” and “organizational behavior”; identifies the most common types of destructive labor behavior, such as absenteeism, theft, sabotage, lowered labor activity, and their key features; considers their negative consequences, such as decreased production, decline in the quality of products or services, conflicts in the team, tensions between workers and employers; analyzes different classifications of the destructive forms of labor behavior. The author concludes that we need a general classification of the destructive forms of labor behavior based on their grouping on three grounds: the essence of the negative consequences of the destructive behavior; the violated legal norms; the causes of the destructive behavior. Moreover, the article identifies three groups of organizational factors that can generate destructive forms of labor behavior - production factors (content, organization and conditions of work, social factors (group relations and psychological (personal characteristics of employees - and provides recommendations to reduce their impact on the organization.

  16. Influence of Kaolin in Fly Ash Based Geopolymer Concrete: Destructive and Non-Destructive Testing

    Science.gov (United States)

    Yahya, Z.; Abdullah, M. M. A. B.; Ramli, N. Mohd; Burduhos-Nergis, D. D.; Razak, R. Abd

    2018-06-01

    Development of geopolymer concrete is mainly to reduce the production of ordinary Portland cement (OPC) that adverse the natural effect. Fly ash is a by-product collected from electrical generating power plant which resulted from burning pulverized coal. Since fly ash is waste materials, it can be recycled for future advantages particularly as pozzolanic materials in construction industry. This study focused on the feasibility of fly ash based geopolymer concrete to which kaolin has been added. The main constituents of geopolymer production for this study were class F fly ash, sodium silicate and sodium hydroxide (NaOH) solution. The concentration of NaOH solution was fixed at 12 Molar, ratio of fly ash/alkaline activator and sodium silicate/NaOH fixed at 1.5 and 2.5, respectively. Kaolin was added in range 5% to 15% from the mass of fly ash and all the samples were cured at room temperature. Destructive and non-destructive test were performed on geopolymer concrete to evaluate the best mix proportions that yield the highest strength as well as the quality of the concrete. Compressive strength, flexural strength, rebound hammer and ultrasonic pulse velocity (UPV) result have been obtained. It shown that 5% replacement of kaolin contributed to maximum compressive strength and flexural strength of 40.4 MPa and 12.35 MPa at 28 days. These result was supported by non-destructive test for the same mix proportion.

  17. Destruction of high explosives and wastes containing high explosives using the molten salt destruction process

    International Nuclear Information System (INIS)

    Upadhye, R.S.; Brummond, W.A.; Pruneda, C.O.

    1992-01-01

    This paper reports the Molten Salt Destruction (MSD) Process which has been demonstrated for the destruction of HE and HE-containing wastes. MSD has been used by Rockwell International and by Anti-Pollution Systems to destroy hazardous wastes. MSD converts the organic constituents (including the HE) of the waste into non-hazardous substances such as carbon dioxide, nitrogen and water. In the case of HE-containing mixed wastes, any actinides in the waste are retained in the molten salt, thus converting the mixed wastes into low-level wastes. (Even though the MSD process is applicable to mixed wastes, this paper will emphasize HE-treatment.) The destruction of HE is accomplished by introducing it, together with oxidant gases, into a crucible containing a molten salt, such as sodium carbonate, or a suitable mixture of the carbonates of sodium, potassium, lithium and calcium. The temperature of the molten salt can be between 400 to 900 degrees C. The combustible organic components of the waste react with oxygen to produce carbon dioxide, nitrogen and steam

  18. Mediation Analysis with Multiple Mediators.

    Science.gov (United States)

    VanderWeele, T J; Vansteelandt, S

    2014-01-01

    Recent advances in the causal inference literature on mediation have extended traditional approaches to direct and indirect effects to settings that allow for interactions and non-linearities. In this paper, these approaches from causal inference are further extended to settings in which multiple mediators may be of interest. Two analytic approaches, one based on regression and one based on weighting are proposed to estimate the effect mediated through multiple mediators and the effects through other pathways. The approaches proposed here accommodate exposure-mediator interactions and, to a certain extent, mediator-mediator interactions as well. The methods handle binary or continuous mediators and binary, continuous or count outcomes. When the mediators affect one another, the strategy of trying to assess direct and indirect effects one mediator at a time will in general fail; the approach given in this paper can still be used. A characterization is moreover given as to when the sum of the mediated effects for multiple mediators considered separately will be equal to the mediated effect of all of the mediators considered jointly. The approach proposed in this paper is robust to unmeasured common causes of two or more mediators.

  19. Explosive destruction of "2"6Al

    International Nuclear Information System (INIS)

    Kahl, D.; Yamaguchi, H.; Shimizu, H.

    2016-01-01

    The γ-ray emission associated with the radioactive decay of "2"6Al is one of the key pieces of observational evidence indicating stellar nucleosynthesis is an ongoing process in our Galaxy, and it was the first such radioactivity to be detected. Despite numerous efforts in stellar modeling, observation, nuclear theory, and nuclear experiment over the past four decades, the precise sites and origin of Galactic "2"6Al remain elusive. We explore the present experimental knowledge concerning the destruction of "2"6Al in massive stars. The precise stellar rates of neutron-induced reactions on "2"6Al, such as (n,p) and (n,α), have among the largest impacts on the total "2"6Al yield. Meanwhile, reactions involving the short-lived isomeric state of "2"6Al such as radiative proton capture are highly-uncertain at present. Although we presented on-going experimental work from n TOF at CERN with an "2"6Al target, the present proceeding focuses only on the "2"6Al isomeric radioactive beam production aspect and the first experimental results at CRIB.

  20. European Non Destructive Examination Forum (ENDEF)

    Energy Technology Data Exchange (ETDEWEB)

    Deffrennes, M [EC, DG XVII, Nuclear Energy, Brussels (Belgium); Engl, G [Siemens AG Energieerzeugung KWU, Erlangen (Germany); Estorff, U von [EC, JRC/IAM, Petten (Netherlands)

    1998-11-01

    ENDEF, an initiative of the European Commission, DG XVII (Energy) was well supported by the European industrial institutions working in assistance with nuclear industrial organisations in the CEEC`s (Central and Eastern European Countries) and NIS`s (New Independent States). This Forum provides effectively a platform for open discussion between representatives of industrial actors active in the NDE (Non Destructive Examination)/ISI (In Service Inspection) field with the purpose to establish a co-operation pattern between qualified representatives of the EU (European Union) industry to offer a better co-ordinated and well defined assistance to the CEEC`s and NIS in the field of NDE/ISI, and to lay the ground for further industrial co-operation. ENDEF developed a strategy to follow for the establishment of co-operation projects. This strategy is now used to understand the extent of past or present assistance projects and to identify the areas where more co-operation is needed. ENDEF encourages the creation in the NIS`s and CEEC`s of similar forums in order to increase the co-operation and co-ordination. ENDEF is also working in perfect agreement with the European Network ENIQ, piloted by the European plant operators. This identity of views lead to the leadership by the ENDEF co-ordinator of the ENIQ Task 3 involving Applications of the European Methodology for ISI qualification in the CEEC`s and NIS`s and presently fully integrated in ENDEF. (orig.)

  1. Non Destructive Analysis of Uranium by Radiometry

    International Nuclear Information System (INIS)

    Yusuf Nampira

    2007-01-01

    Uranium used in nuclear fuel development activity. the Substance use incurred by regulation safeguard. On that account in uranium acceptance conducted by verification of according to document by the specification of goods. Verification done by analysing performed uranium. The activity require by analyse method which simple and rapid analyses and has accurate result of analyses, is hence done by validation of non destructive uranium analysis that is with count gamma radiation from 235 U and product decay from 238 U. Quantitative analysis of uranium in substance determined by through count radiation-g at energy 185.72 keV and the use assess ratio of gamma radiation count from 235 U to 234 Pa to determine isotope content 235 U in substance. The result of analyses were given result of analysis with above correctness storey level 95% and have limit detect equivalent by 0.0174 mg U in U 3 O 8 . This method use at isotope uranium-235 analysis through count gamma radiation comparing method 235 U/ 234 Pa giving accuracy level 95% at sample equivalent uranium its content in 1 g uranium with isotope 235 U smaller than 75 weight percent. (author)

  2. Waste salt recovery, recycle, and destruction

    International Nuclear Information System (INIS)

    Hickman, R.G.

    1992-12-01

    Starting in 1943 and continuing into the 1970s, radioactive wastes resulting from plutonium processing at Hanford were stored underground in 149 single shell tanks. Of these tanks, 66 are known or believedto be leaking, and over a period are believed to have leaked about 750,000 gal into the surrounding soil. The bulk of the aqueous solution has been removed and transferred to double shell tanks, none of which are leaking. The waste consists of 37 million gallons of salt cake and sludge. Most of the salt cake is sodium nitrate and other sodium salts. A substantial fraction of the sludge is sodium nitrate. Small amounts of the radionuclides are present in the sludge as oxides or hydroxides. In addition, some of the tanks contain organic compounds and ferrocyanide complexes, many of which have undergone radiolytic induced chemical changes during the years of storage. As part of the Hanford site remediation effort, the tank wastes must be removed, treated, and the residuals must be immobilized and disposed of in an environmentally acceptable manner. Removal methods of the waste from the tanks fall generally into three approaches: dry removal, slurry removal, and solution removed. The latter two methods are likely to result in some additional leakage to the surrounding soil, but that may be acceptable if the tank can be emptied and remediated before the leaked material permeates deeply into the soil. This effort includes three parts: salt splitting, acid separation, and destruction, with initial emphasis on salt splitting

  3. Modelling of fiberglass pipe destruction process

    Directory of Open Access Journals (Sweden)

    А. К. Николаев

    2017-03-01

    Full Text Available The article deals with important current issue of oil and gas industry of using tubes made of high-strength composite corrosion resistant materials. In order to improve operational safety of industrial pipes it is feasible to use composite fiberglass tubes. More than half of the accidents at oil and gas sites happen at oil gathering systems due to high corrosiveness of pumped fluid. To reduce number of accidents and improve environmental protection we need to solve the issue of industrial pipes durability. This problem could be solved by using composite materials from fiberglass, which have required physical and mechanical properties for oil pipes. The durability and strength can be monitored by a fiberglass winding method, number of layers in composite material and high corrosion-resistance properties of fiberglass. Usage of high-strength composite materials in oil production is economically feasible; fiberglass pipes production is cheaper than steel pipes. Fiberglass has small volume weight, which simplifies pipe transportation and installation. In order to identify the efficiency of using high-strength composite materials at oil production sites we conducted a research of their physical-mechanical properties and modelled fiber pipe destruction process.

  4. Triggering of destructive earthquakes in El Salvador

    Science.gov (United States)

    Martínez-Díaz, José J.; Álvarez-Gómez, José A.; Benito, Belén; Hernández, Douglas

    2004-01-01

    We investigate the existence of a mechanism of static stress triggering driven by the interaction of normal faults in the Middle American subduction zone and strike-slip faults in the El Salvador volcanic arc. The local geology points to a large strike-slip fault zone, the El Salvador fault zone, as the source of several destructive earthquakes in El Salvador along the volcanic arc. We modeled the Coulomb failure stress (CFS) change produced by the June 1982 and January 2001 subduction events on planes parallel to the El Salvador fault zone. The results have broad implications for future risk management in the region, as they suggest a causative relationship between the position of the normal-slip events in the subduction zone and the strike-slip events in the volcanic arc. After the February 2001 event, an important area of the El Salvador fault zone was loaded with a positive change in Coulomb failure stress (>0.15 MPa). This scenario must be considered in the seismic hazard assessment studies that will be carried out in this area.

  5. European Non Destructive Examination Forum (ENDEF)

    International Nuclear Information System (INIS)

    Deffrennes, M.; Engl, G.; Estorff, U. von

    1998-01-01

    ENDEF, an initiative of the European Commission, DG XVII (Energy) was well supported by the European industrial institutions working in assistance with nuclear industrial organisations in the CEEC's (Central and Eastern European Countries) and NIS's (New Independent States). This Forum provides effectively a platform for open discussion between representatives of industrial actors active in the NDE (Non Destructive Examination)/ISI (In Service Inspection) field with the purpose to establish a co-operation pattern between qualified representatives of the EU (European Union) industry to offer a better co-ordinated and well defined assistance to the CEEC's and NIS in the field of NDE/ISI, and to lay the ground for further industrial co-operation. ENDEF developed a strategy to follow for the establishment of co-operation projects. This strategy is now used to understand the extent of past or present assistance projects and to identify the areas where more co-operation is needed. ENDEF encourages the creation in the NIS's and CEEC's of similar forums in order to increase the co-operation and co-ordination. ENDEF is also working in perfect agreement with the European Network ENIQ, piloted by the European plant operators. This identity of views lead to the leadership by the ENDEF co-ordinator of the ENIQ Task 3 involving Applications of the European Methodology for ISI qualification in the CEEC's and NIS's and presently fully integrated in ENDEF. (orig.)

  6. 32 CFR 644.494 - Donation, abandonment or destruction.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Donation, abandonment or destruction. 644.494 Section 644.494 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) REAL... Land) § 644.494 Donation, abandonment or destruction. (a) General. Improvements may be abandoned...

  7. 9 CFR 2.129 - Confiscation and destruction of animals.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Confiscation and destruction of animals. 2.129 Section 2.129 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL WELFARE REGULATIONS Miscellaneous § 2.129 Confiscation and destruction of...

  8. 9 CFR 54.7 - Procedures for destruction of animals.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Procedures for destruction of animals. 54.7 Section 54.7 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT... SCRAPIE Scrapie Indemnification Program § 54.7 Procedures for destruction of animals. (a) Scrapie-positive...

  9. 27 CFR 25.221 - Voluntary destruction of beer.

    Science.gov (United States)

    2010-04-01

    ... beer. 25.221 Section 25.221 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS BEER Voluntary Destruction § 25.221 Voluntary destruction of beer. (a) On brewery premises. (1) A brewer may destroy, at the brewery, beer on which the tax has not...

  10. Self-Destructive Behavior in People with Dissociative Disorders.

    Science.gov (United States)

    Saxe, Glenn N.; Chawla, Neharika; Van der Kolk, Bessel

    2002-01-01

    Study assesses self-destructive behavior in a group of inpatients who have dissociative disorders compared to those who report few dissociative symptoms. Results reveal that these patients more frequently engage in self-destructive behaviors, use more methods of self-injury, and begin to injure themselves at an earlier age then patients who do not…

  11. 50 CFR 28.43 - Destruction of dogs and cats.

    Science.gov (United States)

    2010-10-01

    ... 50 Wildlife and Fisheries 6 2010-10-01 2010-10-01 false Destruction of dogs and cats. 28.43 Section 28.43 Wildlife and Fisheries UNITED STATES FISH AND WILDLIFE SERVICE, DEPARTMENT OF THE INTERIOR... VIOLATIONS OF PARTS 25, 26, AND 27 Impoundment Procedures § 28.43 Destruction of dogs and cats. Dogs and cats...

  12. Radiation, chemical and biological protection. Mass destruction weapons

    International Nuclear Information System (INIS)

    Janasek, D.; Svetlik, J.

    2005-01-01

    In this text-book mass destruction weapons and radiation, chemical and biological protection are reviewed. The text-book contains the following chapter: (1) Mass destruction weapons; (2) Matter and material; (3) Radioactive materials; (4) Toxic materials; (5) Biological resources; (6) Nuclear energetic equipment; Appendices; References.

  13. Destructive Leadership: The Hatfield and McCoy Feud

    Science.gov (United States)

    Sparks, George; Wolf, Patricia; Zurick, Andryce M.

    2015-01-01

    This paper explores the phenomenon of destructive leadership using the historical case study of the feud between the Hatfields and McCoys. The characteristics of destructive leadership as well as the consequences of this leadership style are reviewed, examined and analyzed. Utilizing a case from history to shine light on a contemporary problem,…

  14. Recent canadian experience in chemical warfare agent destruction. An overview

    Energy Technology Data Exchange (ETDEWEB)

    McAndless, J.M.

    1995-09-01

    A Canadian chemical warfare agent destruction project (Swiftsure) was recently completed in which stockpiles of aged mustard, lewisite, nerve agents and contaminated scrap metal were incinerated or chemically neutralized in a safe, environmentally-responsible manner. The project scope, destruction technologies, environmental monitoring and public consultation programs are described.

  15. 19 CFR 191.44 - Destruction under Customs supervision.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Destruction under Customs supervision. 191.44 Section 191.44 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY (CONTINUED) DRAWBACK Rejected Merchandise § 191.44 Destruction under Customs supervision. A claimant may destroy merchandise an...

  16. 19 CFR 191.37 - Destruction under Customs supervision.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Destruction under Customs supervision. 191.37 Section 191.37 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY (CONTINUED) DRAWBACK Unused Merchandise Drawback § 191.37 Destruction under Customs supervision. A claimant may destroy...

  17. 19 CFR 191.25 - Destruction under Customs supervision.

    Science.gov (United States)

    2010-04-01

    ... 19 Customs Duties 2 2010-04-01 2010-04-01 false Destruction under Customs supervision. 191.25 Section 191.25 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE TREASURY (CONTINUED) DRAWBACK Manufacturing Drawback § 191.25 Destruction under Customs supervision. A claimant may destroy merchandise...

  18. 27 CFR 24.294 - Destruction of wine.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Destruction of wine. 24..., DEPARTMENT OF THE TREASURY LIQUORS WINE Removal, Return and Receipt of Wine Removals Without Payment of Tax § 24.294 Destruction of wine. (a) General. Wine on bonded wine premises may be destroyed on or off wine...

  19. Mediated electrochemical oxidation of organic wastes using a Co(III) mediator in a neutral electrolyte

    International Nuclear Information System (INIS)

    Balazs, G.B.; Lewis, P.R.

    1999-01-01

    An electrochemical cell with a Co(III) mediator and neutral pH anolyte provides efficient destruction of organic and mixed wastes. The organic waste is concentrated in the anolyte reservoir, where the cobalt mediator oxidizes the organics and insoluble radioactive species and is regenerated at the anode until all organics are converted to carbon dioxide and destroyed. The neutral electrolyte is non-corrosive, and thus extends the lifetime of the cell and its components. 2 figs

  20. IL-17 receptor A signaling is protective in infection-stimulated periapical bone destruction.

    Science.gov (United States)

    AlShwaimi, Emad; Berggreen, Ellen; Furusho, Hisako; Rossall, Jonathan Caleb; Dobeck, Justine; Yoganathan, Subbiah; Stashenko, Philip; Sasaki, Hajime

    2013-08-15

    IL-17 is a pleiotropic cytokine produced by Th17 T cells that induces a myriad of proinflammatory mediators. However, different models of inflammation report opposite functional roles of IL-17 signal in terms of its effects on bone destruction. In this study we determined the role of IL-17RA signal in bone resorption stimulated by dentoalveolar infections. Infrabony resorptive lesions were induced by surgical pulp exposure and microbial infection of mouse molar teeth. IL-17 was strongly induced in periapical tissues in wild-type (WT) mice by 7 d after the infection but was not expressed in uninfected mice. Dentoalveolar infections of IL-17RA knockout (KO) mice demonstrated significantly increased bone destruction and more abscess formation in the apical area compared with WT mice. Infected IL-17RA KO mice exhibited significantly increased neutrophils and macrophages compared with the WT littermates at day 21, suggesting a failure of transition from acute to chronic inflammation in the IL-17RA KO mice. The expression of IL-1 (both α and β isoforms) and MIP2 were significantly upregulated in the IL-17RA KO compared with WT mice at day 21 postinfection. The development of periapical lesions in IL-17RA KO mice was significantly attenuated by neutralization of IL-1β and MIP2. Taken together, these results demonstrate that IL-17RA signal seems to be protective against infection-induced periapical inflammation and bone destruction via suppression of neutrophil and mononuclear inflammation.

  1. DECONTAMINATION/DESTRUCTION TECHNOLOGY DEMONSTRATION FOR ORGANICS IN TRANSURANIC WASTE

    Energy Technology Data Exchange (ETDEWEB)

    Chris Jones; Javier Del Campo; Patrick Nevins; Stuart Legg

    2002-08-01

    The United States Department of Energy's Savannah River Site has approximately 5000 55-gallon drums of {sup 238}Pu contaminated waste in interim storage. These may not be shipped to WIPP in TRUPACT-II containers due to the high rate of hydrogen production resulting from the radiolysis of the organic content of the drums. In order to circumvent this problem, the {sup 238}Pu needs to be separated from the organics--either by mineralization of the latter or by decontamination by a chemical separation. We have conducted ''cold'' optimization trials and surrogate tests in which a combination of a mediated electrochemical oxidation process (SILVER II{trademark}) and ultrasonic mixing have been used to decontaminate the surrogate waste materials. The surrogate wastes were impregnated with copper oxalate for plutonium dioxide. Our process combines both mineralization of reactive components (such cellulose, rubber, and oil) and surface decontamination of less reactive materials such as polyethylene, polystyrene and polyvinylchloride. By using this combination of SILVER II and ultrasonic mixing, we have achieved 100% current efficiency for the destruction of the reactive components. We have demonstrated that: The degree of decontamination achieved would be adequate to meet both WIPP waste acceptance criteria and TRUPACT II packaging and shipping requirements; The system can maintain near absolute containment of the surrogate radionuclides; Only minimal pre-treatment (coarse shredding) and minimal waste sorting are required; The system requires minimal off gas control processes and monitoring instrumentation; The laboratory trials have developed information that can be used for scale-up purposes; The process does not produce dioxins and furans; Disposal routes for secondary process arisings have already been demonstrated in other programs. Based on the results from Phase 1, the recommendation is to proceed to Phase 2 and use the equipment at Savannah

  2. Modeling the Effect of APC Truncation on Destruction Complex Function in Colorectal Cancer Cells

    Science.gov (United States)

    Barua, Dipak; Hlavacek, William S.

    2013-01-01

    In colorectal cancer cells, APC, a tumor suppressor protein, is commonly expressed in truncated form. Truncation of APC is believed to disrupt degradation of β—catenin, which is regulated by a multiprotein complex called the destruction complex. The destruction complex comprises APC, Axin, β—catenin, serine/threonine kinases, and other proteins. The kinases and , which are recruited by Axin, mediate phosphorylation of β—catenin, which initiates its ubiquitination and proteosomal degradation. The mechanism of regulation of β—catenin degradation by the destruction complex and the role of truncation of APC in colorectal cancer are not entirely understood. Through formulation and analysis of a rule-based computational model, we investigated the regulation of β—catenin phosphorylation and degradation by APC and the effect of APC truncation on function of the destruction complex. The model integrates available mechanistic knowledge about site-specific interactions and phosphorylation of destruction complex components and is consistent with an array of published data. We find that the phosphorylated truncated form of APC can outcompete Axin for binding to β—catenin, provided that Axin is limiting, and thereby sequester β—catenin away from Axin and the Axin-recruited kinases and . Full-length APC also competes with Axin for binding to β—catenin; however, full-length APC is able, through its SAMP repeats, which bind Axin and which are missing in truncated oncogenic forms of APC, to bring β—catenin into indirect association with Axin and Axin-recruited kinases. Because our model indicates that the positive effects of truncated APC on β—catenin levels depend on phosphorylation of APC, at the first 20-amino acid repeat, and because phosphorylation of this site is mediated by , we suggest that is a potential target for therapeutic intervention in colorectal cancer. Specific inhibition of is predicted to limit binding of β—catenin to truncated

  3. OLDAPS: Obsidian Least Destructive Analysis Provenancing System

    Energy Technology Data Exchange (ETDEWEB)

    Eder, F.M.; Sterba, J.H.; Bichler, M. [Atominstitut, Vienna University of Technology, Vienna (Austria); Neelmeijer, C.; Merchel, S. [Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden (Germany); Pearce, N.J.G. [Institute of Geography and Earth Sciences, Aberystwyth University, Wales (United Kingdom)

    2013-07-01

    Full text: The natural volcanic glass obsidian is one of the classical objects of archaeometric analyses. Reliable provenancing by means of the highly specific chemical composition, the 'chemical fingerprint', can provide information about trading routes, extension of territory, long-distance contacts and the mobility of prehistoric people. Since the pioneer work of Cann and Renfrew in 1964 [1] various analytical methods have been employed on obsidian samples in order to locate their provenance. The existing data already offers important knowledge about long-distance interactions between prehistoric human populations. However, most applied techniques just show a small part of the element spectrum. Latest studies showed that published results gained by different analytical methods are not consistent due to systematic errors [2-3]. Therefore, the application of three complementary analytical techniques on the same set of raw material samples allows both a better characterization of obsidian sources and a comparison and validation of analytical results. The aim of this multi-methodical approach is to apply in particular: 1) lon Beam Analysis (IBA) comprising of Particle Induced X-ray Emission (PIXE) and Particle Induced Gamma-ray Emission (PIGE), 2) Instrumental Neutron Activation Analysis (INAA), 3) Laser Ablation-lnductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS), to detect a maximum element spectrum and to compare element concentrations determined with at least two analytical techniques. This approach should check the accuracy and reliability of analytical results and should show a maximum of compositional differences between European obsidian sources to reveal the most characteristic 'chemical fingerprint' composed of more than 40 elements. These investigations are part of a new multi-methodical analytical database called the 'Obsidian Least Destructive Analysis Provenancing System' (OLDAPS). This novel scientific approach for

  4. Combining data in non-destructive testing

    International Nuclear Information System (INIS)

    Lavayssiere, B.

    1994-03-01

    Non-destructive testing of some components requires quite often the use of several methods such as X-ray, ultrasonics, Eddy Currents. But the efficiency of a NDT method is highly dependent on the fact that the detectability of flaws in a specimen relies on the choice of the best method. Moreover a lot of inspection issues could benefit from the use of more than one test method, as each NDT method has its own physical properties and technological limits. Some questions still remain: how to combine data, at what level and for what functionality. Simple monomethod processes are well-known now. They include techniques like reconstruction which belongs to the so-called ill-posed problems in the field of mathematics. For NDT data processing, it has the ability to estimate real data from distorted ones coming from a probe. But, up to now there has been very few approaches for computer aided combination of results from different advanced techniques. This report presents the various mathematical fields involved towards that goal (statistical decision theory which allows the use of multiple hypothesis, non-linear decision theory for its capability to classify and to discriminate, graph theory to find the optimal path in an hypothesis graph and also fuzzy logic, multiple resolution analysis, artificial intelligence,...) and which combinations of methods are useful. Some images will illustrate this topic in which EDF is involved, and will explain what are the major goals of this work. Combining is not only an improvement of 3D visualisation which would allow to display simultaneously CAD or NDT data for example, but it consists in exploiting multisensor data collected via a variety of sophisticated techniques and presenting this information to the operator without overloading the operator/system capacities in order to reduce the uncertainty and to resolve the ambiguity inherent to mono method inspection. (author). 7 figs., 35 refs

  5. NITRATE DESTRUCTION LITERATURE SURVEY AND EVALUATION CRITERIA

    Energy Technology Data Exchange (ETDEWEB)

    Steimke, J.

    2011-02-01

    This report satisfies the initial phase of Task WP-2.3.4 Alternative Sodium Recovery Technology, Subtask 1; Develop Near-Tank Nitrate/Nitrite Destruction Technology. Some of the more common anions in carbon steel waste tanks at SRS and Hanford Site are nitrate which is corrosive, and nitrite and hydroxide which are corrosion inhibitors. At present it is necessary to periodically add large quantities of 50 wt% caustic to waste tanks. There are three primary reasons for this addition. First, when the contents of salt tanks are dissolved, sodium hydroxide preferentially dissolves and is removed. During the dissolution process the concentration of free hydroxide in the tank liquid can decrease from 9 M to less than 0.2 M. As a result, roughly half way through the dissolution process large quantities of sodium hydroxide must be added to the tank to comply with requirements for corrosion control. Second, hydroxide is continuously consumed by reaction with carbon dioxide which occurs naturally in purge air used to prevent buildup of hydrogen gas inside the tanks. The hydrogen is generated by radiolysis of water. Third, increasing the concentration of hydroxide increases solubility of some aluminum compounds, which is desirable in processing waste. A process that converts nitrate and nitrite to hydroxide would reduce certain costs. (1) Less caustic would be purchased. (2) Some of the aluminum solid compounds in the waste tanks would become more soluble so less mass of solids would be sent to High Level Vitrification and therefore it would be not be necessary to make as much expensive high level vitrified product. (3) Less mass of sodium would be fed to Saltstone at SRS or Low Level Vitrification at Hanford Site so it would not be necessary to make as much low level product. (4) At SRS less nitrite and nitrate would be sent to Defense Waste Processing Facility (DWPF) so less formic acid would be consumed there and less hydrogen gas would be generated. This task involves

  6. Cell Lysis and Detoxification of Cyanotoxins Using a Novel Combination of Microbubble Generation and Plasma Microreactor Technology for Ozonation.

    Science.gov (United States)

    Pandhal, Jagroop; Siswanto, Anggun; Kuvshinov, Dmitriy; Zimmerman, William B; Lawton, Linda; Edwards, Christine

    2018-01-01

    There has been a steady rise in the incidences of algal blooms globally, and worryingly, there is increasing evidence that changes in the global climate are leading to a shift toward cyanobacterial blooms. Many cyanobacterial genera are harmful, producing several potent toxins, including microcystins, for which there are over 90 described analogues. There are a wide range of negative effects associated with these toxins including gastroenteritis, cytotoxicity, hepatotoxicity and neurotoxicity. Although a variety of oxidation based treatment methods have been described, ozonation and advanced oxidation are acknowledged as most effective as they readily oxidise microcystins to non-toxic degradation products. However, most ozonation technologies have challenges for scale up including high costs and sub-optimum efficiencies, hence, a low cost and scalable ozonation technology is needed. Here we designed a low temperature plasma dielectric barrier discharge (DBD) reactor with an incorporated fluidic oscillator for microbubble delivery of ozone. Both technologies have the potential to drastically reduce the costs of ozonation at scale. Mass spectrometry analysis revealed very rapid (cyanotoxins.

  7. Microbubbles combined with ultrasound therapy in ischemic stroke: A systematic review of in-vivo preclinical studies.

    Directory of Open Access Journals (Sweden)

    Laurent Auboire

    Full Text Available Microbubbles (MBs combined with ultrasound sonothrombolysis (STL appears to be an alternative therapeutic strategy for acute ischemic stroke (IS, but clinical results remain controversial.The aim of this systematic review is to identify the parameters tested; to assess evidence on the safety and efficacy on preclinical data on STL; and to assess the validity and publication bias.Pubmed® and Web of ScienceTM databases were systematically searched from January 1995 to April 2017 in French and English. We included studies evaluating STL on animal stroke model. This systematic review was conducted in accordance with the PRISMA guidelines. Data were extracted following a pre-defined schedule by two of the authors. The CAMARADES criteria were used for quality assessment. A narrative synthesis was conducted.Sixteen studies met the inclusion criteria. The result showed that ultrasound parameters and types of MBs were heterogeneous among studies. Numerous positive outcomes on efficacy were found, but only four studies demonstrated superiority of STL versus recombinant tissue-type plasminogen activator on clinical criteria. Data available on safety are limited.Quality assessment of the studies reviewed revealed a number of biases.Further in vivo studies are needed to demonstrate a better efficacy and safety of STL compared to currently approved therapeutic options.http://syrf.org.uk/protocols/.

  8. Focal hepatic lesions: contrast-enhancement patterns at pulse-inversion harmonic US using a microbubble contrast agent

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eun-A; Yoon, Kwon-Ha; Lee, Young-Hwan; Kim, Hye-Won; Juhng, Seon-Kwan; Won, Jong-Jin [Wonkwang University, Iksan (Korea, Republic of)

    2003-12-15

    To analyze the contrast-enhancement patterns obtained at pulse-inversion harmonic imaging (PIHI) of focal hepatic lesions, and to thus determine tumor vascularity and the acoustic emission effect. We reviewed pulse-inversion images in 90 consecutive patients with focal hepatic lesions, namely hepatocellular carcinoma (HHC) (n=43), metastases (n=30), and hemangioma (n=17). Vascular and delayed phase images were obtained immediately and five minutes following the injection of a microbubble contrast agent. Tumoral vascularity at vascular phase imaging and the acoustic emission effect at delayed phase imaging were each classified as one of four patterns. Vascular phase images depicted internal vessels in 93% of HCCs, marginal vessels in 83% of metastases, and peripheral enhancement in 71% of hemangiomas. Delayed phase images showed inhomogeneous enhancement in 86% of HCCs; hypoechoic, decreased enhancement in 93% of metastases; and hypoechoic and reversed echogenicity in 65% of hemangiomas. Vascular and delayed phase enhancement patterns were associated with a specificity of 91% or greater, and 92% or greater, respectively, and with positive predictive values of 71% or greater, and 85% or greater, respectively. Contrast-enhancement patterns depicting tumoral vascularity and the acoustic emission effect at PIHI can help differentiate focal hepatic lesions.

  9. Blood-Brain Barrier Opening in Behaving Non-Human Primates via Focused Ultrasound with Systemically Administered Microbubbles

    Science.gov (United States)

    Downs, Matthew E.; Buch, Amanda; Karakatsani, Maria Eleni; Konofagou, Elisa E.; Ferrera, Vincent P.

    2015-10-01

    Over the past fifteen years, focused ultrasound coupled with intravenously administered microbubbles (FUS) has been proven an effective, non-invasive technique to open the blood-brain barrier (BBB) in vivo. Here we show that FUS can safely and effectively open the BBB at the basal ganglia and thalamus in alert non-human primates (NHP) while they perform a behavioral task. The BBB was successfully opened in 89% of cases at the targeted brain regions of alert NHP with an average volume of opening 28% larger than prior anesthetized FUS procedures. Safety (lack of edema or microhemorrhage) of FUS was also improved during alert compared to anesthetized procedures. No physiological effects (change in heart rate, motor evoked potentials) were observed during any of the procedures. Furthermore, the application of FUS did not disrupt reaching behavior, but in fact improved performance by decreasing reaction times by 23 ms, and significantly decreasing touch error by 0.76 mm on average.

  10. Mediation Analysis with Multiple Mediators

    OpenAIRE

    VanderWeele, T.J.; Vansteelandt, S.

    2014-01-01

    Recent advances in the causal inference literature on mediation have extended traditional approaches to direct and indirect effects to settings that allow for interactions and non-linearities. In this paper, these approaches from causal inference are further extended to settings in which multiple mediators may be of interest. Two analytic approaches, one based on regression and one based on weighting are proposed to estimate the effect mediated through multiple mediators and the effects throu...

  11. Schumpeter's process of creative destruction and the Scandinavian systems

    DEFF Research Database (Denmark)

    Andersen, Esben Sloth; Dahl, Michael Slavensky; Lundvall, Bengt-Åke

    The paper studies of the process of creative destruction according to Schumpeter's programme of making a 'Theoretical, Historical, and Statistical Analysis of the Capitalist Process'. He had both a Mark I and a Mark II of concept of creative destruction, and they are important for understanding...... the coevolution between economic life and socio-political life. A method for partitioning of evolutionary change into a selection effect and an innovation effect is described, and sketches of the historical experience of Denmark and Sweden are made accordingly. Finally, a statistical study of creative destruction...

  12. Destructiveness criteria for seismic risk evaluation of nuclear power plant

    International Nuclear Information System (INIS)

    Saragoni, G.R.

    1995-01-01

    Two criteria of destructiveness for seismic risk evaluation of nuclear power plant are presented. The first one is a simple linear criterion that allows to compute average response spectra in terms of earthquake accelerogram characteristics. The second defines the destructiveness potential factor P D which measures the capacity of earthquake to produce nonlinear damage. This second criterion that shows large differences of destructiveness capacity for earthquake accelerograms of different seismic environment, specially between subductive and transcursive, is strongly recommended. (author). 8 refs., 1 fig. 1 tab

  13. "Cold combustion" as a new method of toxic waste destruction

    Directory of Open Access Journals (Sweden)

    Екатерина Юрьевна Ткаченко

    2015-05-01

    Full Text Available This article describes a promising new method for the destruction of toxic industrial waste, obsolete pesticides and military poisons and explosives. The proposed method can be used to create mobile modular units that will produce the destruction of the "field", to clean the soil and water containing low concentrations of a pollutant, to solve the problem of disposal of explosives, which is often accompanied by the destruction of uncontrolled detonation. The proposed method is environmentally friendly, using ice as the working body

  14. Destructive spondyloarthropathy and radiographic follow-up in hemodialysis patients

    International Nuclear Information System (INIS)

    Orzincolo, C.; Cardona, P.; Bedani, P.L.; Gilli, P.; Scutellari, P.N.; Trotta, F.

    1990-01-01

    Nine patients undergoing regular dialytic treatment for more than 60 months showed clinical and radiologic features of a noninfective and destructive spondyloarthropathy. Typically, radiographs and CT scans revealed narrowing of intervertebral spaces, with destruction or sclerosis of the subchondral bone of the vertebral plate. A radiographic follow-up of the cervical spine was performed in seven patients after a period of 12 months and showed that the bone destruction in DSA is very rapid and progressive. The lower biocompatibility of the cuprophan membranes of dialyzers is probably the factor most responsible for hyperproduction of β 2 -m and subsequently osteoarticular deposition of a new type of amyloidosis. (orig./DG)

  15. Modelling, simulation and visualisation for electromagnetic non-destructive testing

    International Nuclear Information System (INIS)

    Ilham Mukriz Zainal Abidin; Abdul Razak Hamzah

    2010-01-01

    This paper reviews the state-of-the art and the recent development of modelling, simulation and visualization for eddy current Non-Destructive Testing (NDT) technique. Simulation and visualization has aid in the design and development of electromagnetic sensors and imaging techniques and systems for Electromagnetic Non-Destructive Testing (ENDT); feature extraction and inverse problems for Quantitative Non-Destructive Testing (QNDT). After reviewing the state-of-the art of electromagnetic modelling and simulation, case studies of Research and Development in eddy current NDT technique via magnetic field mapping and thermography for eddy current distribution are discussed. (author)

  16. Tank 50H Tetraphenylborate Destruction Results

    International Nuclear Information System (INIS)

    Peters, T.B.

    2003-01-01

    We conducted several scoping tests with both Tank 50H surrogate materials (KTPB and phenol) as well as with actual Tank 50H solids. These tests examined whether we could destroy the tetraphenylborate in the surrogates or actual Tank 50H material either by use of Fenton's Reagent or by hydrolysis (in Tank 50H conditions at a maximum temperature of 50 degrees C) under a range of conditions. The results of these tests showed that destruction of the solids occurred only under a minority of conditions. (1)Using Fenton's Reagent and KTPB as the Tank 50H surrogate, no reaction occurred at pH ranges greater than 9. (2)Using Fenton's Reagent and phenol as the Tank 50H surrogate, no reaction occurred at a pH of 14. (3)Using Fenton's Reagent and actual Tank 50H slurry, a reaction occurred at a pH of 9.5 in the presence of ECC additives. (4)Using Fenton's Reagent and actual Tank 50H slurry, after a thirty three day period, all attempts at hydrolysis (at pH 14) were too slow to be viable. This happened even in the case of higher temperature (50 degrees C) and added (100 ppm) copper. Tank 50H is scheduled to return to HLW Tank Farm service with capabilities of transferring and receiving salt supernate solutions to and from the Tank Farms and staging feed for the Saltstone Facility. Before returning Tank 50H to Tank Farm service as a non-organic tank, less than 5 kg of TPB must remain in Tank 50H. Recently, camera inspections in Tank 50H revealed two large mounds of solid material, one in the vicinity of the B5 Riser Transfer Pump and the other on the opposite side of the tank. Personnel sampled and analyzed this material to determine its composition. The sample analysis indicated presence of a significant quantity of organics in the solid material. This quantity of organic material exceeds the 5 kg limit for declaring only trace amounts of organic material remain in Tank 50H. Additionally, these large volumes of solids, calculated as approximately 61K gallons, present other

  17. Quantitative evaluation of contrast-enhanced ultrasound after intravenous administration of a microbubble contrast agent for differentiation of benign and malignant thyroid nodules: assessment of diagnostic accuracy.

    Science.gov (United States)

    Nemec, Ursula; Nemec, Stefan F; Novotny, Clemens; Weber, Michael; Czerny, Christian; Krestan, Christian R

    2012-06-01

    To investigate the diagnostic accuracy, through quantitative analysis, of contrast-enhanced ultrasound (CEUS), using a microbubble contrast agent, in the differentiation of thyroid nodules. This prospective study enrolled 46 patients with solitary, scintigraphically non-functional thyroid nodules. These patients were scheduled for surgery and underwent preoperative CEUS with pulse-inversion harmonic imaging after intravenous microbubble contrast medium administration. Using histology as a standard of reference, time-intensity curves of benign and malignant nodules were compared by means of peak enhancement and wash-out enhancement relative to the baseline intensity using a mixed model ANOVA. ROC analysis was performed to assess the diagnostic accuracy in the differentiation of benign and malignant nodules on CEUS. The complete CEUS data of 42 patients (31/42 [73.8%] benign and 11/42 [26.2%] malignant nodules) revealed a significant difference (P benign and malignant nodules. Furthermore, based on ROC analysis, CEUS demonstrated sensitivity of 76.9%, specificity of 84.8% and accuracy of 82.6%. Quantitative analysis of CEUS using a microbubble contrast agent allows the differentiation of benign and malignant thyroid nodules and may potentially serve, in addition to grey-scale and Doppler ultrasound, as an adjunctive tool in the assessment of patients with thyroid nodules. • Contrast-enhanced ultrasound (CEUS) helps differentiate between benign and malignant thyroid nodules. • Quantitative CEUS analysis yields sensitivity of 76.9% and specificity of 84.8%. • CEUS may be a potentially useful adjunct in assessing thyroid nodules.

  18. Predicting Tropical Cyclone Destructive Potential by Integrated Kinetic Energy According to the Powell/Reinhold Scale

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A method of predicting the destructive capacity of a tropical cyclone based on a new Wind Destructive Potential (WDP) and Storm Surge Destructive Potential (SDP)...

  19. Destructive electronics from electrochemical-mechanically triggered chemical dissolution

    International Nuclear Information System (INIS)

    Sim, Kyoseung; Wang, Xu; Yu, Cunjiang; Li, Yuhang; Linghu, Changhong; Song, Jizhou; Gao, Yang

    2017-01-01

    The considerable need to enhance data and hardware security suggest one possible future for electronics where it is possible to destroy them and even make them disappear physically. This paper reports a type of destructive electronics which features fast transience from chemical dissolution on-demand triggered in an electrochemical-mechanical manner. The detailed materials, mechanics, and device construction of the destructive electronics are presented. Experiment and analysis of the triggered releasing and transience study of electronic materials, resistors and metal-oxide-semiconductor field effect transistors illustrate the key aspects of the destructive electronics. The reported destructive electronics is useful in a wide range of areas from security and defense, to medical applications (paper)

  20. Advanced non-destructive methods for an efficient service performance

    International Nuclear Information System (INIS)

    Rauschenbach, H.; Clossen-von Lanken Schulz, M.; Oberlin, R.

    2015-01-01

    Due to the power generation industry's desire to decrease outage time and extend inspection intervals for highly stressed turbine parts, advanced and reliable Non-destructive methods were developed by Siemens Non-destructive laboratory. Effective outage performance requires the optimized planning of all outage activities as well as modern Non-destructive examination methods, in order to examine the highly stressed components (turbine rotor, casings, valves, generator rotor) reliably and in short periods of access. This paper describes the experience of Siemens Energy with an ultrasonic Phased Array inspection technique for the inspection of radial entry pinned turbine blade roots. The developed inspection technique allows the ultrasonic inspection of steam turbine blades without blade removal. Furthermore advanced Non-destructive examination methods for joint bolts will be described, which offer a significant reduction of outage duration in comparison to conventional inspection techniques. (authors)

  1. Cartagena declaration on renunciation of weapons of mass destruction

    International Nuclear Information System (INIS)

    1992-02-01

    The document reproduces the text of the Cartagena Declaration on Renunciation of Weapons of Mass Destruction, signed by the Presidents of Bolivia, Colombia, Ecuador, Peru and Venezuela at Cartagena de Indias, Colombia, on 4 December 1991

  2. Eliminating Adversary Weapons of Mass Destruction: What's at Stake?

    National Research Council Canada - National Science Library

    Hersman, Rebecca K

    2004-01-01

    .... Unfortunately, the current preoccupation with intelligence might mask other issues and shortcomings in the American ability to eliminate the threat posed by weapons of mass destruction in the hands of its enemies...

  3. Periodontal tissue destruction caused by an elastic orthodontic ...

    African Journals Online (AJOL)

    Once this cooperation is lost, possible negative effects may be the consequence. ... that arises when elastic orthodontic spacers are being used in the mouth. Key words: Open-flap curettage, Orthodontic spacer, Periodontal destruction ...

  4. Preparation of Metallochelating Microbubbles and Study on Their Site-Specific Interaction with rGFP-HisTag as a Model Protein

    Czech Academy of Sciences Publication Activity Database

    Lukáč, R.; Kauerová, Z.; Mašek, J.; Bartheldyová, E.; Kulich, P.; Koudelka, Š.; Korvasová, Z.; Plocková, J.; Papoušek, František; Kolář, František; Schmidt, R.; Turánek, J.

    2011-01-01

    Roč. 27, č. 8 (2011), s. 4829-4837 ISSN 0743-7463 R&D Projects: GA AV ČR KAN200520703 Grant - others:GA ČR(CZ) GAP304/10/1951; GA AV ČR(CZ) KAN200100801 Program:GA; KA Institutional research plan: CEZ:AV0Z50110509 Keywords : microbubble * ultrasound imaging * metallochelating bond * rGFP * liposome * contrast echocardiography * static light scattering * flow * cytometry * confocal Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 4.186, year: 2011

  5. Evaluation of destructive methods for managing decontamination wastes

    International Nuclear Information System (INIS)

    Piciulo, P.L.; Adams, J.W.

    1986-01-01

    Results are discussed of a laboratory evaluation of destructive methods for processing chemical decontamination wastes. Incineration, acid digestion and wet-air oxidation are capable of degrading decontamination reagents and organic ion-exchange resins. The extent of destruction as a function of operating parameters was waste specific. The reagents used in the testing were: EDTA, oxalic acid, citric acid, picolinic acid and LND-101A

  6. The Strip: Las Vegas and the Symbolic Destruction of Spectacle

    OpenAIRE

    Al, Stefan Johannes

    2010-01-01

    Over the past 70 years, various actors have dramatically reconfigured the Las Vegas Strip in many forms. I claim that behind the Strip's "reinventions" lies a process of symbolic destruction. Since resorts distinguish themselves symbolically, each new round of capital accumulation relies on the destruction of symbolic capital of existing resorts. A new resort either ups the language within a paradigm, or causes a paradigm shift, which devalues the previous resorts even further. This is why, i...

  7. The Combine Use of Semi-destructive and Non-destructive Methods for Tiled Floor Diagnostics

    Science.gov (United States)

    Štainbruch, Jakub; Bayer, Karol; Jiroušek, Tomáš; Červinka, Josef

    2017-04-01

    The combination of semi-destructive and non-destructive methods was used to asset the conditions of a tiled floor in the historical monument Minaret, situated in the park complex of the Chateau Lednice (South Moravia Region, Czech Republic), before its renovation. Another set of measurements is going to be performed after the conservation works are finished. (The comparison of the results collected during pre- and post-remediation measurements will be known and presented during the General Assembly meeting in Wien.) The diagnostic complex of methods consisted of photogrammetry, resistivity drilling and georadar. The survey was aimed to contour extends of air gaps beneath the tiles and the efficiency of filling gaps by means of injection, consolidation and gluing individual layers. The state chateau Lednice creates a part of the Lednice-Valtice precinct, a UNESCO landmark, and belongs among the greatest historic monuments in Southern Moravia. In the chateau park there is a romantic observation tower in the shape of a minaret built according to the plans of Josef Hardtmuth between 1798-1804. The Minaret has been extensively renovated for many decades including the restoration of mosaic floors from Venetian terazzo. During the static works of the Minaret building between 1999-2000, the mosaic floors in the rooms on the second floor were transferred and put back onto concrete slabs. Specifically, the floor was cut up to tiles and these were glued to square slabs which were then attached to the base plate. The transfer was not successful and the floor restoration was finalized between 2016-2017. The damage consisted in separating the original floor from the concrete plate which led to creating gaps. Furthermore, the layers of the floor were not compact. It was necessary to fill the gaps and consolidate and glue the layers. The existence of air gap between individual layers of the tiles and their degradation was detected using two different diagnostic methods: semi-destructive

  8. The results of cutting disks testing for rock destruction

    Directory of Open Access Journals (Sweden)

    Khoreshok Aleksey

    2017-01-01

    Full Text Available To determine the rational order of disk tools placement on the working body is necessary to know the maximum amount of rock, destroyed by the disk tool in benching cutting mode depending on the tool geometry parameters, physical and mechanical parameters of rocks. The article contains the definition of rational parameters of cutting disk tools as well as power and energy parameters of the destruction process by cutting disks and by executive body of the coal cutter. The rational geometric parameters of cutting discs are specified. It was found that each step of cutting with a minimum depth of penetration has its own maximum height of bench outcrop. The dependence of the volumes of large items destroyed by the disk tool on the cutting step height was determined. The existence of the cyclic alternation of destruction phases, regardless the fracture parameters, the height of the ledge outcrop, and tools like free cutting geometry were found. In contrast to the free cutting in benching mode of destruction two large fragments of rocks in one cycle were observed. Consequently, the cyclical nature of the destruction process in the benching mode will be characterized by two chips and crushing, and this cycling repeats throughout the destruction process with the same parameters of destruction.

  9. Bioeffects of albumin-encapsulated microbubbles and real-time myocardial contrast echocardiography in an experimental canine model

    Directory of Open Access Journals (Sweden)

    P.M.M. Dourado

    2006-06-01

    Full Text Available Myocardial contrast echocardiography has been used for assessing myocardial perfusion. Some concerns regarding its safety still remain, mainly regarding the induction of microvascular alterations. We sought to determine the bioeffects of microbubbles and real-time myocardial contrast echocardiography (RTMCE in a closed-chest canine model. Eighteen mongrel dogs were randomly assigned to two groups. Nine were submitted to continuous intravenous infusion of perfluorocarbon-exposed sonicated dextrose albumin (PESDA plus continuous imaging using power pulse inversion RTMCE for 180 min, associated with manually deflagrated high-mechanical index impulses. The control group consisted of 3 dogs submitted to continuous imaging using RTMCE without PESDA, 3 dogs received PESDA alone, and 3 dogs were sham-operated. Hemodynamics and cardiac rhythm were monitored continuously. Histological analysis was performed on cardiac and pulmonary tissues. No hemodynamic changes or cardiac arrhythmias were observed in any group. Normal left ventricular ejection fraction and myocardial perfusion were maintained throughout the protocol. Frequency of mild and focal microhemorrhage areas in myocardial and pulmonary tissue was similar in PESDA plus RTMCE and control groups. The percentages of positive microscopical fields in the myocardium were 0.4 and 0.7% (P = NS in the PESDA plus RTMCE and control groups, respectively, and in the lungs they were 2.1 and 1.1%, respectively (P = NS. In this canine model, myocardial perfusion imaging obtained with PESDA and RTMCE was safe, with no alteration in cardiac rhythm or left ventricular function. Mild and focal myocardial and pulmonary microhemorrhages were observed in both groups, and may be attributed to surgical tissue manipulation.

  10. Hemocoagulase Combined with Microbubble-Enhanced Ultrasound Cavitation for Augmented Ablation of Microvasculature in Rabbit VX2 Liver Tumors.

    Science.gov (United States)

    Yang, Qian; Tang, Peng; He, Guangbin; Ge, Shuping; Liu, Liwen; Zhou, Xiaodong

    2017-08-01

    We investigated a new method for combining microbubble-enhanced ultrasound cavitation (MEUC) with hemocoagulase (HC) atrox. Our goal was to induce embolic effects in the vasculature and combine these with an anti-angiogenic treatment strategy. Fourteen days after being implanted with a single slice of the liver VX2 tumor, rabbits were randomly divided into five groups: (i) a control group injected intra-venously with saline using a micropump; (ii) a group given only an injection of HC; (iii) a group treated only with ultrasound cavitation; (iv) a group treated with MEUC; (v) a group treated with MEUC + HC. Contrast-enhanced ultrasound was performed before treatment and 1 h and 7 d post-treatment to measure tumor size, enhancement and necrosis range. QontraXt software was used to determine the time-intensity curve of tumor blood perfusion and microvascular changes. At 1 h and 7 d after treatment with MEUC + HC, the parameters of the time-intensity curve, which included peak value, regional blood volume, regional blood flow and area under the curve value and which were measured using contrast-enhanced ultrasound, were significantly lower than those of the other treatment groups. The MEUC + HC treatment group exhibited significant growth inhibition relative to the ultrasound cavitation only, HC and MEUC treatment groups. No damage was observed in the surrounding normal tissues. These results support the feasibility of reducing the blood perfusion of rabbit VX2 liver tumors using a new method that combines MEUC and HC. Copyright © 2017 World Federation for Ultrasound in Medicine & Biology. All rights reserved.

  11. Effect of acoustic parameters on the cavitation behavior of SonoVue microbubbles induced by pulsed ultrasound.

    Science.gov (United States)

    Lin, Yutong; Lin, Lizhou; Cheng, Mouwen; Jin, Lifang; Du, Lianfang; Han, Tao; Xu, Lin; Yu, Alfred C H; Qin, Peng

    2017-03-01

    SonoVue microbubbles could serve as artificial nuclei for ultrasound-triggered stable and inertial cavitation, resulting in beneficial biological effects for future therapeutic applications. To optimize and control the use of the cavitation of SonoVue bubbles in therapy while ensuring safety, it is important to comprehensively understand the relationship between the acoustic parameters and the cavitation behavior of the SonoVue bubbles. An agarose-gel tissue phantom was fabricated to hold the SonoVue bubble suspension. 1-MHz transmitting transducer calibrated by a hydrophone was used to trigger the cavitation of SonoVue bubbles under different ultrasonic parameters (i.e., peak rarefactional pressure (PRP), pulse repetition frequency (PRF), and pulse duration (PD)). Another 7.5-MHz focused transducer was employed to passively receive acoustic signals from the exposed bubbles. The ultraharmonics and broadband intensities in the acoustic emission spectra were measured to quantify the extent of stable and inertial cavitation of SonoVue bubbles, respectively. We found that the onset of both stable and inertial cavitation exhibited a strong dependence on the PRP and PD and a relatively weak dependence on the PRF. Approximate 0.25MPa PRP with more than 20μs PD was considered to be necessary for ultraharmonics emission of SonoVue bubbles, and obvious broadband signals started to appear when the PRP exceeded 0.40MPa. Moreover, the doses of stable and inertial cavitation varied with the PRP. The stable cavitation dose initially increased with increasing PRP, and then decreased rapidly after 0.5MPa. By contrast, the inertial cavitation dose continuously increased with increasing PRP. Finally, the doses of both stable and inertial cavitation were positively correlated with PRF and PD. These results could provide instructive information for optimizing future therapeutic applications of SonoVue bubbles. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Complex Mediation

    DEFF Research Database (Denmark)

    Bødker, Susanne; Andersen, Peter Bøgh

    2005-01-01

    This article has its starting point in a large number of empirical findings regarding computer-mediated work. These empirical findings have challenged our understanding of the role of mediation in such work; on the one hand as an aspect of communication and cooperation at work and on the other hand...... as an aspect of human engagement with instruments of work. On the basis of previous work in activity-theoretical and semiotic human—computer interaction, we propose a model to encompass both of these aspects. In a dialogue with our empirical findings we move on to propose a number of types of mediation...... that have helped to enrich our understanding of mediated work and the design of computer mediation for such work....

  13. Ultrasonic Analysis of Peptide- and Antibody-Targeted Microbubble Contrast Agents for Molecular Imaging of αvβ3-Expressing Cells

    Directory of Open Access Journals (Sweden)

    Paul A. Dayton

    2004-04-01

    Full Text Available The goal of targeted ultrasound contrast agents is to significantly and selectively enhance the detection of a targeted vascular site. In this manuscript, three distinct contrast agents targeted to the αvβ3 integrin are examined. The αvβ3 integrin has been shown to be highly expressed on metastatic tumors and endothelial cells during neovascularization, and its expression has been shown to correlate with tumor grade. Specific adhesion of these contrast agents to αvβ3-expressing cell monolayers is demonstrated in vitro, and compared with that of nontargeted agents. Acoustic studies illustrate a backscatter amplitude increase from monolayers exposed to the targeted contrast agents of up to 13-fold (22 dB relative to enhancement due to control bubbles. A linear dependence between the echo amplitude and bubble concentration was observed for bound agents. The decorrelation of the echo from adherent targeted agents is observed over successive pulses as a function of acoustic pressure and bubble density. Frequency–domain analysis demonstrates that adherent targeted bubbles exhibit high-amplitude narrowband echo components, in contrast to the primarily wideband response from free microbubbles. Results suggest that adherent targeted contrast agents are differentiable from free-floating microbubbles, that targeted contrast agents provide higher sensitivity in the detection of angiogenesis, and that conventional ultrasound imaging techniques such as signal subtraction or decorrelation detection can be used to detect integrin-expressing vasculature with sufficient signal-to-noise.

  14. Improved survival in rats with glioma using MRI-guided focused ultrasound and microbubbles to disrupt the blood-brain barrier and deliver Doxil

    Science.gov (United States)

    Aryal, Muna; Zhi Zhang, Yong; Vykhodtseva, Natalia; Park, Juyoung; Power, Chanikarn; McDannold, Nathan

    2012-02-01

    Blood-brain-barrier (BBB) limits the transportation of most neuropeptides, proteins (enzymes, antibodies), chemotherapeutic agents, and genes that have therapeutic potential for the treatment of brain diseases. Different methods have been used to overcome this limitation, but they are invasive, non-targeted, or require the development of new drugs. We have developed a method that uses MRI-guided focused ultrasound (FUS) combined with circulating microbubbles to temporarily open BBB in and around brain tumors to deliver chemotherapy agents. Here, we tested whether this noninvasive technique could enhance the effectiveness of a chemotherapy agent (Doxil). Using 690 kHz FUS transducer and microbubble (Definity), we induced BBB disruption in intracranially-implanted 9L glioma tumors in rat's brain in three weekly sessions. Animals who received BBB disruption and Doxil had a median survival time of 34.5 days, which was significantly longer than that found in control animals which is 16, 18.5, 21 days who received no treatment, BBB disruption only and Doxil only respectively This work demonstrates that FUS technique has promise in overcoming barriers to drug delivery, which are particularly stark in the brain due to the BBB.

  15. Contrast-Enhanced Ultrasound with VEGFR2-Targeted Microbubbles for Monitoring Regorafenib Therapy Effects in Experimental Colorectal Adenocarcinomas in Rats with DCE-MRI and Immunohistochemical Validation.

    Directory of Open Access Journals (Sweden)

    Ralf Stefan Eschbach

    Full Text Available To investigate contrast-enhanced ultrasound (CEUS with VEGFR2-targeted microbubbles for monitoring therapy effects of regorafenib on experimental colon carcinomas in rats with correlation to dynamic contrast-enhanced MRI (DCE-MRI and immunohistochemistry.Human colorectal adenocarcinoma xenografts (HT-29 were implanted subcutaneously in n = 21 (n = 11 therapy group; n = 10 control group female athymic nude rats (Hsd: RH-Foxn1rnu. Animals were imaged at baseline and after a one-week daily treatment with regorafenib or a placebo (10 mg/kg bodyweight, using CEUS with VEGFR2-targeted microbubbles and DCE-MRI. In CEUS tumor perfusion was assessed during an early vascular phase (wash-in area under the curve = WiAUC and VEGFR2-specific binding during a late molecular phase (signal intensity after 8 (SI8min and 10 minutes (SI10min, using a conventional 15L8 linear transducer (transmit frequency 7 MHz, dynamic range 80 dB, depth 25 mm. In DCE-MRI functional parameters plasma flow (PF and plasma volume (PV were quantified. For validation purposes, CEUS parameters were correlated with DCE-MRI parameters and immunohistochemical VEGFR2, CD31, Ki-67 and TUNEL stainings.CEUS perfusion parameter WiAUC decreased significantly (116,989 ± 77,048 a.u. to 30,076 ± 27,095a.u.; p = 0.005 under therapy with no significant changes (133,932 ± 65,960 a.u. to 84,316 ± 74,144 a.u.; p = 0.093 in the control group. In the therapy group, the amount of bound microbubbles in the late phase was significantly lower in the therapy than in the control group on day 7 (SI8min: 283 ± 191 vs. 802 ± 460 a.u.; p = 0.006; SI10min: 226 ± 149 vs. 645 ± 461 a.u.; p = 0.009. PF and PV decreased significantly (PF: 147 ± 58 mL/100 mL/min to 71 ± 15 mL/100 mL/min; p = 0.003; PV: 13 ± 3% to 9 ± 4%; p = 0.040 in the therapy group. Immunohistochemistry revealed significantly fewer VEGFR2 (7.2 ± 1.8 vs. 17.8 ± 4.6; p < 0.001, CD31 (8.1 ± 3.0 vs. 20.8 ± 5.7; p < 0.001 and Ki-67 (318.7

  16. β-Catenin destruction complex-independent regulation of Hippo–YAP signaling by APC in intestinal tumorigenesis

    Science.gov (United States)

    Cai, Jing; Maitra, Anirban; Anders, Robert A.; Taketo, Makoto M.; Pan, Duojia

    2015-01-01

    Mutations in Adenomatous polyposis coli (APC) underlie familial adenomatous polyposis (FAP), an inherited cancer syndrome characterized by the widespread development of colorectal polyps. APC is best known as a scaffold protein in the β-catenin destruction complex, whose activity is antagonized by canonical Wnt signaling. Whether other effector pathways mediate APC's tumor suppressor function is less clear. Here we report that activation of YAP, the downstream effector of the Hippo signaling pathway, is a general hallmark of tubular adenomas from FAP patients. We show that APC functions as a scaffold protein that facilitates the Hippo kinase cascade by interacting with Sav1 and Lats1. Consistent with the molecular link between APC and the Hippo signaling pathway, genetic analysis reveals that YAP is absolutely required for the development of APC-deficient adenomas. These findings establish Hippo–YAP signaling as a critical effector pathway downstream from APC, independent from its involvement in the β-catenin destruction complex. PMID:26193883

  17. Guidebook on destructive examination of water reactor fuel

    International Nuclear Information System (INIS)

    1997-01-01

    As a result of common efforts of fuel vendors, utilities and research institutes the average burnup pf design batch fuels was increased for both PWRs and BWRs and the fuel failure rate has been reduced. The previously published Guidebook on Non-Destructive Examination of Water Reactor Fuel recommended that more detailed destructive techniques are required for complete understanding of fuel performance. On the basis of contributions of the 14 participants in the ED-WARF-II CRP and proceedings of IAEA Technical Committee on Recent Developments in Post-irradiation Examination Techniques for Water Reactor Fuel this guidebook was compiled. It gives a complete survey of destructive techniques available to date worldwide. The following examination techniques are described in detailed including major principles of equipment design: microstructural studies; elemental analysis; isotopic analysis; measurement of physical properties; measurement of mechanical properties. Besides the examination techniques, methods for refabrication of experimental rods from high burnup power reactor rods as well as methods for verification of non-destructive techniques by using destructive techniques is included

  18. Hamster and Murine Models of Severe Destructive Lyme Arthritis

    Science.gov (United States)

    Munson, Erik; Nardelli, Dean T.; Du Chateau, Brian K.; Callister, Steven M.; Schell, Ronald F.

    2012-01-01

    Arthritis is a frequent complication of infection in humans with Borrelia burgdorferi. Weeks to months following the onset of Lyme borreliosis, a histopathological reaction characteristic of synovitis including bone, joint, muscle, or tendon pain may occur. A subpopulation of patients may progress to a chronic, debilitating arthritis months to years after infection which has been classified as severe destructive Lyme arthritis. This arthritis involves focal bone erosion and destruction of articular cartilage. Hamsters and mice are animal models that have been utilized to study articular manifestations of Lyme borreliosis. Infection of immunocompetent LSH hamsters or C3H mice results in a transient synovitis. However, severe destructive Lyme arthritis can be induced by infecting irradiated hamsters or mice and immunocompetent Borrelia-vaccinated hamsters, mice, and interferon-gamma- (IFN-γ-) deficient mice with viable B. burgdorferi. The hamster model of severe destructive Lyme arthritis facilitates easy assessment of Lyme borreliosis vaccine preparations for deleterious effects while murine models of severe destructive Lyme arthritis allow for investigation of mechanisms of immunopathology. PMID:22461836

  19. Destruction as a Step in Heidegger\\'s Phenomenology

    Directory of Open Access Journals (Sweden)

    M.J Safian

    2014-09-01

    Full Text Available One of the most controversial issues in Heidegger’s philosophy is his claim that western philosophy tradition has overlooked the issue of Being. Heidegger’s attempt is to reveal the origins of this negligence by means of destruction. However, it seems that through such claim Heidegger aims to destroy and disvalue this tradition. In addition to defining and explaining destruction, our purpose in this article is to show that Heidegger’s goal is not to destroy the tradition of philosophy but the term destruction refers to a process which is a step in Heidegger’s phenomenology by means of which one can conceive and perceive Being better because only through such destruction ontology can fully assure itself in a phenomenological way of the genuine character of its concepts. The necessity of doing destruction in Heidegger’s thought has also been discussed and his persistence on it has been shown in two of his works, one belongs to early and another to later Heidegger.

  20. Indirect self-destructiveness in individuals with schizophrenia

    Directory of Open Access Journals (Sweden)

    Konstantinos Tsirigotis

    2017-06-01

    Full Text Available Objective: To explore the indirect self-destructiveness syndrome in patients with schizophrenia. Methods: Two hundred individuals with paranoid schizophrenia (117 men and 83 women, mean age 37.15 years, all in remission, were examined using the Polish version of the Chronic Self-Destructiveness Scale. Two hundred well-matched healthy individuals served as a control group. Results: The intensity of indirect self-destructiveness was greater in the schizophrenia group than in controls. The intensity of each manifestation was as follows (in decreasing order: helplessness and passiveness in the face of difficulties (A5, personal and social neglects (A3, lack of planfulness (A4, poor health maintenance (A2, transgression and risk (A1. Conclusion: Patients with schizophrenia displayed more behaviors that were indirectly self-destructive than healthy controls; they scored better than healthy controls only on caring for their own health. The patients showed the lowest intensity of behaviors connected with the active form of indirect self-destructiveness, and the highest intensity of behaviors connected with the passive form. These findings may enable delivery of more effective forms of pharmacological and psychosocial help to patients with schizophrenia.