检索结果-南通市图书馆

Monte Carlo Simulation of Scattered Light with Shear Waves Generated by Acoustic Radiation Force for Acousto-Optic Imaging

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2012年第12期29卷 123-126页

作者： LU Ming-Zhu WU Yu-Peng SHI Yu GUAN Yu-Bo GUO Xiao-Li WAN Ming-Xi The Key Laboratory of biomedical Information Engineering of Ministry of Education Department of Biomedical EngineeringSchool of Life Science and TechnologyXi'an Jiaotong UniversityXi'an 710049

A Monte Carlo method of multiple scattered coherent light with the information of shear wave propagation in scattering media is *** established Monte-Carlo algorithm is mainly relative to optical phase variations due to the acoustic-radiation-force shear-wave-induced displacements of light *** the distributions and temporal behaviors of optical phase increments in probe locations are ***,shear wave speed is evaluated *** is noted that the phase increments exactly track the propagations of shear waves induced by focus-ultrasound radiation *** addition,attenuations of shear waves are demonstrated in simulation *** using linear regression processing,the shear wave speed,which is set to 2.1 m/s in simulation,is estimated to be 2.18 m/s and 2.35 m/s at time sampling intervals of 0.2 ms and 0.5 ms,respectively.

关键词： Shear propagation phase

A New Full Bridge High Intensity Focused Ultrasound Power System with Harmonic Cancellation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Shanghai Jiaotong university(Science) 2014年第6期19卷 698-701页

作者：吴昊沈国峰苏志强陈亚珠 biomedical Instrument Institute School of Biomedical Engineering Med-X Research Institute Shanghai Jiaotong University

The feasibility of a new full bridge high intensity focused ultrasound(HIFU) amplifier system with harmonic cancellation is evaluated in this study. Harmonic cancellation technique is applied to these power amplifiers, which can eliminate the 3rd harmonic and all even harmonics. Since this technique requires two channels of phase signal to control one channel of power amplifier, the signal generator is required to double its output. The transducer array proposed in this study has 100 elements. So we choose an FPGA chip to generate 200 driving signals, and each channel has a phase resolution of 2ns, less than 1°. The phase signal from the FPGA meets the requirement of driving the power amplifiers. The output waveform of one channel of power amplifier(voltage across the transducer) is evaluated, and shows fewer harmonic components.

关键词： high intensity focused ultrasound(HIFU) power amplifier field programmable gate array(FPGA) signal generator harmonic cancellation

Propagation of Shear Waves Generated by Acoustic Radiation Force in Nondissipative Inhomogeneous Media

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2012年第1期29卷 164-167页

作者： LU Ming-Zhu LIU Xue-Jin SHI Yu KANG Yan-Ni GUAN Yu-Bo WAN Ming-Xi The Key Laboratory of biomedical Information Engineering of Ministry of Education Department of Biomedical EngineeringSchool of Life Science and TechnologyXi’an Jiaotong UniversityXi’an 710049

We concentrate on the nondissipative mechanism induced shear wave in inhomogenous *** shear wave equation of radiation force in inhomogeneous media is solved numerically with a finite-difference time-domain method.A rarely studied nondissipative mechanism of shear displacement due to a smooth medium inhomogeneity is *** is noted that unlike the dissipative effect,the nondissipative action on a localized inhomogeneity with its hardness parameter changing smoothly along the beam axis,compresses or stretches the focus *** shear waves in nondissipative inhomogeneous media remain the property of sharp turn with 100% peak positive displacement and 64% peak negative *** action is useful in discerning the water-like lesion.

关键词： method. dissipative inhomogeneous

Real-Time MRI-Controlled Ultrasound Hyperthermia System for Superficial Tumor Treatment

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Shanghai Jiaotong university(Science) 2014年第6期19卷 715-717页

作者：朱梦媛沈国峰苏志强陈晟吴昊 biomedical Instrument Institute School of Biomedical Engineering Med-X Research Institute Shanghai Jiaotong University

Ultrasound hyperthermia is one of the most important methods in tumor treatment and characterized by non-invasiveness. Magnetic resonance imaging(MRI)-based temperature mapping techniques are safe compared with invasive methods and have been applied to detect temperature changes for a variety of applications. Among these techniques, the proton resonance frequency(PRF) method is relatively advanced. With a temperature measuring experiment, the effectiveness of PRF method has been proved, because the outcome temperature curve and the real temperature curve fit well. After that, an experiment has been conducted on tumors inside rabbit legs and the result indicates that this system is able to performance hyperthermia at targets based on PRF method in temperature mapping.

关键词： ultrasound hyperthermia magnetic resonance imaging(MRI) proton resonance frequency(PRF) method

NON-LINEAR OPTICAL IMAGING OF OBESITY-RELATED HEALTH RISKS:REVIEW

在线全文

学校读者我要写书评

暂无评论

Journal of Innovative Optical Health Sciences 2009年第1期2卷 9-25页

作者： THUC T.LE JI-XIN CHENG Weldon school of biomedical Engineering Purdue University West Lafayette Indiana 47907USA Department of Chemistry and Weldon school of biomedical Engineering Purdue University West Lafayette Indiana 47907USA

This review highlights the recent applications of non-linear optical(NLO)microscopy to study obesity-related health risks.A strong emphasis is given to the applications of coherent anti-Stokes Raman scattering(CARS)microscopy where multiple non-linear optical imaging modalities including CARS,sum-frequency generation(SFG),and two-photon fluorescence are employed simultaneously on a single microscope *** examples on applications of NLO microscopy to study lipid-droplet biology,obesity-cancer relationship,atherosclerosis,and lipidrich biological structures are discussed.

关键词： Atherosclerosis coherent anti-Stokes Raman scattering lipid droplet mammary cancer non-linear optics obesity second harmonic generation sum-frequency generation twophoton fluorescence tumor stroma

Effects of adjacent bubble on spatiotemporal evolutions of mechanical stresses surrounding bubbles oscillating in tissues

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2023年第1期32卷 354-361页

作者：邹青钦雷双李章勇秦对 Department of biomedical Engineering School of BioinformaticsChongqing University of Posts and TelecommunicationsChongqing 400065China

The cavitation dynamics and mechanical stress in viscoelastic tissues, as the primary mechanisms of some ultrasound therapies, are extremely complex due to the interactions of cavitation bubble with adjacent bubbles and surrounding ***, the cavitation dynamics and resultant mechanical stress of two-interacting bubbles in the viscoelastic tissues are numerically investigated, especially focusing on the effects of the adjacent bubble. The results demonstrate that the mechanical stress is highly dependent on the bubble dynamics. The compressive stress and tensile stress are generated at the stage of bubble expansion and collapse stage, respectively. Furthermore, within the initial parameters examined in this paper, the effects of the adjacent bubble will distinctly suppress the radial expansion of the small bubble and consequently lead its associated stresses to decrease. Owing to the superimposition of two stress fields, the mechanical stresses surrounding the small bubble in the direction of the neighboring bubble are smaller than those in other directions. For two interacting cavitation bubbles, the suppression effects of the nearby bubble on both the cavitation dynamics and the stresses surrounding the small bubble increase as the ultrasound amplitude and the initial radius of the large bubble increase, whereas they decrease with the inter-bubble distance increasing. Moreover, increasing the tissue viscoelasticity will reduce the suppression effects of the nearby bubble, except in instances where the compressive stress and tensile stress first increase and then decrease with the tissue elasticity and viscosity increasing respectively. This study can provide a further understanding of the mechanisms of cavitation-associated mechanical damage to the adjacent tissues or cells.

关键词： cavitation dynamics cavitation-induced mechanical stress effects of the nearby bubble viscoelastic tissues

A novel two-dimensional nanoheterojunction via facilitating electron–hole pairs separation for synergistic tumor phototherapy and immunotherapy

在线全文

学校读者我要写书评

暂无评论

Nano Research 2023年第5期16卷 7148-7163页

作者： Xiaoge Zhang Xiaomei Chen Peng Zhang Meiting Li Miao Feng Yaqian Zhang Lili Cheng Junjie Tang Langtao Xu Yadong Liu Zhuoyin Liu Zhong Cao Jie Liu school of biomedical Engineering Shenzhen Campus of Sun Yat-sen UniversityShenzhen 518107China

Nanomaterial-mediated phototherapy in tumor treatment has been developed rapidly in the past few years due to its noninvasive ***,the low energy conversion efficiency and high recombination rate of the photo-triggered electron–hole pairs of single nano-agent limit the phototherapy ***,we constructed a novel two-dimensional nanoheterojunction MoS_(2)-Ti_(3)C_(2)(MT),which allowed a high photothermal conversion efficiency(59.1%)as well as an effective separation of photo-triggered electron–hole pairs for reactive oxygen species(ROS)generation under single 808 nm laser *** the modification of the mitochondrial targeted molecule(3-proxycarboxylic)triphenyl phosphine bromide(TPP)and 4T1 cell membrane,m@MoS_(2)-Ti_(3)C_(2)/TPP(m@MTT)could effectively target to the tumor cell and further locate to the mitochondria to amplify tumor-specific oxidative stress,which not merely effectively inhibits the local tumor growth but also induces tumor immunogenic cell death(ICD)for activating antitumor immune ***,cytosine guanine dinucleotide(CPG),as a Toll-like receptor 9(TLR9)agonist,was further introduced to the system to boost adaptive immune responses,resulting in improved level of cytotoxic T cells as well as a decrease in the number of regulatory T *** vivo antitumor mechanism studies demonstrated that not only the primary and distant tumors in 4T1 bearing-tumor mice model were significantly inhibited,but also the lung metastasis of tumor was effectively ***,this work revealed the ROS generation mechanism of MT nanoheterojunction and provided a novel strategy to fabricate a biomedically applicable MT nanoheterojunction for tumor treatment.

关键词： two-dimensional nanoheterojunction mitochondrial targeting photothermal therapy photodynamic therapy immunotherapy

Chronological changes in the liver after temporary partial portal venous occlusion

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2013年第34期19卷 5700-5705页

作者： Koji Hamasaki Susumu Eguchi Akihiko Soyama Masaaki Hidaka Mitsuhisa Takatsuki Fumihiko Fujita Kengo Kanetaka Shigeki Minami Tamotsu Kuroki Department of Surgery Nagasaki University Graduate School of Biomedical Sciences

AIM:To investigate time-dependent changes caused by temporal portal vein obstruction and subsequent reperfusion in the lobe with or without an occluded portal ***:The portal vein(PV)of the anterior lobe of the liver of a male Wistar rat(8 wk-old)was obstructed(70%)for 12,24,36 and 48 h,respectively,and models were sacrificed at 48 h after reperfusion(each group:n=10).The histological changes and the status of liver regeneration were compared between a liver biopsy performed on each lobe after temporary obstruction of the portal vein in the same rat liver,and the liver extracted at the time of sacrifice(48 h after reperfusion).RESULTS:With regard to the obstructed lobe,the liver weight/body weight ratio significantly decreased according to obstruction *** the other hand,in thenon-obstructed lobe,there were no significant differences within each *** duration of PV occlusion did not seem to be strong enough to introduce liver weight *** of liver regeneration was brought about in the non-occluded lobe by 12-h occlusion,and was sustained even at 48 h after *** obstructed lobe atrophied with the passage of time in the obstructed ***,the proliferating-cell nuclear antigen labeling index also increased at 48 h after reperfusion,and a repair mechanism was ***:Temporary blood flow obstruction of the portal vein may become a significant trigger for liver regeneration,even with an obstruction of 12 h.

关键词： Temporary Portal vein Occlusion Regeneration Liver

Quality Monitoring of Porous Zein Scaffolds： A Novel Biomaterial

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Engineering 2017年第1期3卷 130-135页

作者： Yue Zhang Wei-Ying Li Run Lan Jin-Ye Wang school of biomedical Engineering Shanghai Jiao Tong University Shanghai 200240 China

Our previous studies have shown that zein has good biocompatibility and good mechanical properties. The first product from a porous scaffold of zein, a resorbable bone substitute, has passed the biological evaluation of medical devices （ISO 10993） by the China Food and Drug Administration. However, Class III medical devices need quality monitoring before being placed on the market, and such monitoring includes quality control of raw materials, choice of sterilization method, and evaluation of biocompatibility. In this paper, we investigated four sources of zein through amino acid analysis （AAA） and sodium dodecyl sulfate polyacrylamide gel electrophoresis （SDS-PAGE） in order to monitor the composition and purity, and control the quality of raw materials. We studied the effect of three kinds of sterilization method on a porous zein scaffold by SDS-PAGE. We also compared the changes in SDS-PAGE patterns when irradiated with different doses of gamma radiation. We found that polymerization or breakage did not occur on peptide chains of zein during gamma-ray （y-ray） sterilization in the range of 20-30 kGy, which suggested that γ-ray sterilization is suitable for porous zein scaffolds, Regarding cell compatibility, we found a difference between using a 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyl tetrazolium bromide （MTT） assay and a cell-counting kit-8 （CCK-8） assay to assess cell proliferation on zein film, and concluded that the CCK-8 assay is more suitable, due to its low background optical density.

关键词： Zein Amino acid analysis SDS-PAGE Gamma-ray sterilization MTF assay CCK-8 assay