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991.
Elastic moduli of normal and pathological human breast tissues: an inversion-technique-based investigation of 169 samples 总被引:1,自引:0,他引:1
Understanding and quantifying the mechanical properties of breast tissues has been a subject of interest for the past two decades. This has been motivated in part by interest in modelling soft tissue response for surgery planning and virtual-reality-based surgical training. Interpreting elastography images for diagnostic purposes also requires a sound understanding of normal and pathological tissue mechanical properties. Reliable data on tissue elastic properties are very limited and those which are available tend to be inconsistent, in part as a result of measurement methodology. We have developed specialized techniques to measure tissue elasticity of breast normal tissues and tumour specimens and applied them to 169 fresh ex vivo breast tissue samples including fat and fibroglandular tissue as well as a range of benign and malignant breast tumour types. Results show that, under small deformation conditions, the elastic modulus of normal breast fat and fibroglandular tissues are similar while fibroadenomas were approximately twice the stiffness. Fibrocystic disease and malignant tumours exhibited a 3-6-fold increased stiffness with high-grade invasive ductal carcinoma exhibiting up to a 13-fold increase in stiffness compared to fibrogalndular tissue. A statistical analysis showed that differences between the elastic modulus of the majority of those tissues were statistically significant. Implications for the specificity advantages of elastography are reviewed. 相似文献
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Soft tissue elasticity has been a subject of interest in biomedical applications as an aid to medical diagnosis since the dawn of medicine. More recently, this has led to the concept of elastography with the aim of imaging the spatial distribution of tissue elasticity. Interpreting elastography images requires reliable information pertaining to elastic properties of normal and pathological tissues. Such information is either very limited or not available in the literature. Elastic modulus measurement techniques developed for soft tissues generally require tissue excision to prepare samples for testing. While this may be done with normal tissues, tumour tissue excision is generally not permissible because tumour pathological assessment requires that the tumour be kept intact. To address this limitation, we developed a system to measure the Young's modulus of tumour specimens. The technique consists of indenting the tumour specimen while measuring indentation force and displacements. To obtain the Young's modulus from the measured force-displacement slope, we developed an iterative inversion technique that uses a finite element model of the piecewise homogeneous tissue slice in each iteration. Preliminary elasticity measurement results of various breast tumours are presented and discussed. These results indicate that the proposed method is robust and highly accurate. Furthermore, they indicate that a benign lesion and malignant tumours are roughly five times and ten times stiffer than normal breast tissues respectively. 相似文献
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Kiyomi Tsuyuki Jessica D. Gipson Regina Maria Barbosa Lianne A. Urada Donald E. Morisky 《Culture, health & sexuality》2018,20(9):1006-1022
Syndemic Zika virus, HIV and unintended pregnancy call for an urgent understanding of dual method (condoms with another modern non-barrier contraceptive) and consistent condom use. Multinomial and logistic regression analysis using data from the Pesquisa Nacional de Demografia e Saúde da Criança e da Mulher (PNDS), a nationally representative household survey of reproductive-aged women in Brazil, identified the socio-demographic, fertility and relationship context correlates of exclusive non-barrier contraception, dual method use and condom use consistency. Among women in marital and civil unions, half reported dual protection (30% condoms, 20% dual methods). In adjusted models, condom use was associated with older age and living in the northern region of Brazil or in urban areas, whereas dual method use (versus condom use) was associated with younger age, living in the southern region of Brazil, living in non-urban areas and relationship age homogamy. Among condom users, consistent condom use was associated with reporting Afro-religion or other religion, not wanting (more) children and using condoms only (versus dual methods). Findings highlight that integrated STI prevention and family planning services should target young married/in union women, couples not wanting (more) children and heterogamous relationships to increase dual method use and consistent condom use. 相似文献
997.
Many commercial and academic institutions protect their commercially valuable research information using patents, making the patent literature a rich and early source of cutting-edge research. While scientists and students often create the data that finds its way into patents, some rarely read the patent literature. Here, we provide an informal and brief collection of hints and tips that may assist scientists and students who do not regularly read the patent literature to locate the key scientific findings that are disclosed by patentees. These tips will introduce the reader to: (i) the general structure of patents and the sections of the patents that scientists and students may find particularly helpful; and (ii) a few factors to keep in mind when using data disclosed in the patent literature, such as patent lifespans, jurisdictions and the patent review processes. Although this is not a comprehensive and complete guide to reading patents, the accessible nature of this informal introduction to patent reading should assist scientists and students to make more effective use of the cutting-edge research disclosed in patent specifications. 相似文献
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Donald G. Klepser Michael E. Klepser Jaclyn K. Smith Allison M. Dering-Anderson Maggie Nelson Lauren E. Pohren 《Research in social & administrative pharmacy》2018,14(4):356-359