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111.
恶性肿瘤的传质问题(Ⅰ)——流体动力学部分 总被引:3,自引:0,他引:3
本文提出肿瘤内部液体和药物传质的三重介质模型·在这部分,研究间隙压力和对流的作用·对于孤立肿瘤和被正常组织包围的肿瘤得到了分析解·计算结果与实验一致,即组织间隙的高压是阻碍药物进入肿瘤的主要原因·文章详细分析了降低间隙压力的参数· 相似文献
112.
本文对彩色多普勒超声(CDUs)结合弹性成像技术(UE)在鉴别乳腺良恶性肿瘤中的应用价值进行了分析。选取2018年1月~2019年2月本院乳腺肿瘤患者103例为研究对象,所有患者均给予CDUs、UE检查,以病理检查为对照,分析CDUs、UE及二者结合对乳腺良恶性肿瘤的鉴别价值。病理检查显示,103例乳腺肿瘤患者中,恶性48例(46.60%)、良性55例(53.40%);乳腺肿瘤恶性者CDUs、UE得分明显高于良性者,差异有统计学意义(P<0.05);在鉴别乳腺良恶性肿瘤的敏感度、特异度、准确度中,CDUs为79.17%、72.73%、75.73%,UE为75.00%、65.45%、69.90%,CDUs与UE结合为95.83%、90.91%、93.20%,CDUs结合UE明显高于CDUs、UE,差异有统计学意义(P<0.05)。本文证实CDUs、UE对乳腺良恶性肿瘤具有良好的鉴别价值,且CDUs结合UE的鉴别价值更高。 相似文献
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A dynamic continuous-flow dialysis (CFD) method with on-line electrothermal atomic absorption spectrometric (ETAAS) and pH measurements for study of simulated gastrointestinal digestion has been developed for prediction of iron bioavailability. The method used to estimate mineral bioavailability was based on gastric digestion in a batch system then dynamic continuous-flow intestinal digestion. The intestinal digestion was performed in a dialysis bag placed inside a chamber containing a flowing stream of dialyzing solution. Mineral concentration and dialysate pH were monitored by ETAAS and use of a pH meter, respectively. The amount of dialyzed minerals in the intestinal digestion stage was used to evaluate the dialyzability. The dialysis profile and pH change can be used to understand or examine differences between the dialyzability of different food samples. To test the proposed system it was used to estimate the iron dialyzability of different kinds of milk. Iron dialyzability for powdered cow milk, cereal milk, and two brands of soymilk was found to be 1.7, 20.4, 24.9, and 37.7%, respectively. The developed CFD–ETAAS–pH system is a simple, rapid, and inexpensive tool for bioavailability studies, especially for minerals at ultratrace levels. 相似文献
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Josh Star-Lack Daniel Spielman Elfar Adalsteinsson John Kurhanewicz David J. Terris Daniel B. Vigneron 《Journal of magnetic resonance (San Diego, Calif. : 1997)》1998,133(2):243-254
Two T2-independentJ-difference lactate editing schemes for the PRESS magnetic resonance spectroscopy localization sequence are introduced. The techniques, which allow for simultaneous acquisition of the lactate doublet (1.3 ppm) and edited singlets upfield of and including choline (3.2 ppm), exploit the dependence of the in-phase intensity of the methyl doublet upon the time interval separating two inversion (BASING) pulses applied to its coupling partner after initial excitation. Editing method 1, which allows for echo times TE =n/J(n= 1, 2, 3, …), alters the BASING carrier frequency for each of two cycles so that, for one cycle, the quartet is inverted, whereas, for the other cycle, the quartet is unaffected. Method 2, which also provides water suppression, allows for editing for TE > 1/Jby alternating, between cycles, the time interval separating the inversion pulses. Experimental results were obtained at 1.5 T using a Shinnar Le–Roux-designed maximum phase inversion pulse with a filter transition bandwidth of 55 Hz. Spectra were acquired from phantoms andin vivofrom the human brain and neck. In a neck muscle study, the lipid suppression factor, achieved partly through the use of a novel phase regularization algorithm, was measured to be over 103. Spectra acquired from a primary brain and a metastatic neck tumor demonstrated the presence of lactate and choline signals consistent with abnormal spectral patterns. The advantages and limitations of the methods are analyzed theoretically and experimentally, and significance of the results is discussed. 相似文献
115.
Dr. Ye Liu Jinfeng Liu Dr. Dandan Chen Xiaosha Wang Zhe Zhang Yicheng Yang Prof. Lihui Jiang Weizhi Qi Ziyuan Ye Prof. Shuqing He Prof. Quanying Liu Prof. Lei Xi Prof. Yingping Zou Prof. Changfeng Wu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(47):21235-21243
Here, we describe a fluorination strategy for semiconducting polymers for the development of highly bright second near-infrared region (NIR-II) probes. Tetrafluorination yielded a fluorescence QY of 3.2 % for the polymer dots (Pdots), over a 3-fold enhancement compared to non-fluorinated counterparts. The fluorescence enhancement was attributable to a nanoscale fluorous effect in the Pdots that maintained the molecular planarity and minimized the structure distortion between the excited state and ground state, thus reducing the nonradiative relaxations. By performing through-skull and through-scalp imaging of the brain vasculature of live mice, we quantitatively analyzed the vascular morphology of transgenic brain tumors in terms of the vessel lengths, vessel branches, and vessel symmetry, which showed statistically significant differences from the wild type animals. The bright NIR-II Pdots obtained through fluorination chemistry provide insightful information for precise diagnosis of the malignancy of the brain tumor. 相似文献
116.
Low-intensity pulsed ultrasound (LIPUS) is an established therapy for fracture repair and has been used widely in the clinics, but its underlying mechanism of action remains unclear. The aim of the current research was to determine the effect of LIPUS on gap junctional cell-to-cell intercellular communication in rat bone marrow stromal cells (BMSC) in vitro and to determine whether the ability of BMSCs to communicate by gap junctions would affect their response to LIPUS. Single or daily-multiple LIPUS treatment at 1.5 MHz, 30 mW/cm2, for 20 min was applied to BMSC. We demonstrated that BMSC form functional gap junctions and single LIPUS treatment significantly increased the intracellular dye transfer between BMSC. In addition, activated phosphorylation of ERK1/2 and p38 by LIPUS stimulation was diminished when cells were treated with a gap junction inhibitor 18β-glycyrrhetinic acid (18β). We further demonstrated that 18β diminished the significant increase in alkaline phosphatase activity following LIPUS stimulation. These results suggest a potential role of gap junctional cell-to-cell intercellular communication on the effects of LIPUS in BMSC. 相似文献
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Mariza Aires-Fernandes Ramon Botelho Costa Stphanie Rochetti do Amaral Cassamo Ussemane Mussagy Valria C. Santos-Ebinuma Fernando Lucas Primo 《Molecules (Basel, Switzerland)》2022,27(20)
Photodynamic therapy (PDT) is a noninvasive therapeutic approach that has been applied in studies for the treatment of various diseases. In this context, PDT has been suggested as a new therapy or adjuvant therapy to traditional cancer therapy. The mode of action of PDT consists of the generation of singlet oxygen (¹O2) and reactive oxygen species (ROS) through the administration of a compound called photosensitizer (PS), a light source, and molecular oxygen (3O2). This combination generates controlled photochemical reactions (photodynamic mechanisms) that produce ROS, such as singlet oxygen (¹O2), which can induce apoptosis and/or cell death induced by necrosis, degeneration of the tumor vasculature, stimulation of the antitumor immune response, and induction of inflammatory reactions in the illuminated region. However, the traditional compounds used in PDT limit its application. In this context, compounds of biotechnological origin with photosensitizing activity in association with nanotechnology are being used in PDT, aiming at its application in several types of cancer but with less toxicity toward neighboring tissues and better absorption of light for more aggressive types of cancer. In this review, we present studies involving innovatively developed PS that aimed to improve the efficiency of PDT in cancer treatment. Specifically, we focused on the clinical translation and application of PS of natural origin on cancer. 相似文献