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Acoustic nanodrops are designed to vaporize into ultrasound-responsive microbubbles, which present certain challenges nonexistent for conventional nanoemulsions. The requirements of biocompatibility, vaporizability, and colloidal stability have focused research on perfluorocarbons. Shorter perfluorocarbons yield better vaporizability via their lower critical temperature, but they also dissolve more easily owing to their higher vapor pressure and solubility. Thus, acoustic nanodrops have required a trade-off between vaporizability and colloidal stability in vivo. The recent advent of vaporizable endoskeletal droplets, which are both colloidally stable and vaporizable, may have solved this problem. The purpose of this review is to justify this premise by pointing out the beneficial properties of acoustic nanodrops, providing an analysis of vaporization and dissolution mechanisms, and reviewing current biomedical applications. 相似文献
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Dr. Luca Conti Prof. Andrea Bencini Prof. Camilla Ferrante Dr. Cristina Gellini Prof. Paolo Paoli Dr. Matteo Parri Prof. Giangaetano Pietraperzia Prof. Barbara Valtancoli Prof. Claudia Giorgi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(45):10606-10615
A comparative study between two novel, highly water soluble, ruthenium(II) polypyridyl complexes, [Ru(phen)2 L ′] and [Ru(phen)2Cu(II) L ′] ( L and L -CuII), containing the polyaazamacrocyclic unit 4,4′-(2,5,8,11,14-pentaaza[15])-2,2′-bipyridilophane ( L ′), is herein reported. L and L -CuII interact with calf-thymus DNA and efficiently cleave DNA plasmid when light-activated. They also possess great penetration abilities and photo-induced biological activities, evaluated on an A375 human melanoma cell line, with L -CuII being the most effective. Our study highlights the key role of the Fenton active CuII center within the macrocycle framework, that would play a synergistic role with light activation in the formation of cytotoxic ROS species. Based on these results, an optimal design of RuII polypyridyl systems featuring specific CuII-chelating polyamine units could represent a suitable strategy for the development of novel and effective photosensitizers in photodynamic therapy. 相似文献
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Radiotherapy treatment is often delivered in a fractionated manner over a period of time. Emerging delivery devices are able to determine the actual dose that has been delivered at each stage facilitating the use of adaptive treatment plans that compensate for errors in delivery. We formulate a model of the day-to-day planning problem as a stochastic program and exhibit the gains that can be achieved by incorporating uncertainty about errors during treatment into the planning process. Due to size and time restrictions, the model becomes intractable for realistic instances. We show how heuristics and neuro-dynamic programming can be used to approximate the stochastic solution, and derive results from our models for realistic time periods. These results allow us to generate practical rules of thumb that can be immediately implemented in current planning technologies. 相似文献
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Robert Thayer Sataloff 《Journal of voice》1987,1(3)
Common problems that are of little consequence to other patients may be disabling to professional singers. Laryngologists must recognize even subtle manifestation of these ailments and be familiar with techniques to treat them without creating undesirable side effects. It is not usually necessary to restrict the trained professional from performing, and absolute voice rest is rarely necessary. Laryngeal surgery should be avoided whenever possible. 相似文献
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We summary recent advances of transformable NPs for nanomedicine. In this review, the transformation of NPs is divided into three groups including changes in size, surface charge and morphology, which is induced by internal stimuli, such as pH, enzyme, receptor or external stimuli, such as light, temperature. 相似文献
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Civilizations in antiquity have endeavored to champion the use of light to treat illnesses in the human body. Although laser light has unique applications in medicine, its mechanism of action for low intensity exposures on cells, tissues, and the body continues to be controversial after nearly 50 years of investigations. This paper presents evidence for visible red and near infrared light to induce (indirect) generation of hydrogen peroxide as an important chemical messenger behind the stimulatory and inhibitory responses observed to low intensity light exposures. It is hypothesized that other ionizing or non‐ionizing modalities can either directly or indirectly induce / or generate H2O2 in an aqueous environment and could also bring about similar stimulatory or inhibitory bio‐effects. One salient parameter which governs the bio‐response is the level of generated H2O2. The authors discuss the mechanism which enables a small amount of hydrogen peroxide generated by light to produce beneficial effects. 相似文献
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The objective of this study was to assess the impact of dynamic range and gain on perfusion quantification using linearized log-compressed data. An indicator-dilution experiment was developed with an in vitro flow phantom setup used with SonoVue contrast agent (Bracco SpA, Milan, Italy). Imaging was performed with a Philips iU22 scanner and a C5-1 curvilinear transducer using a contrast-specific nonlinear pulse sequence (power modulation) at 1.7 MHz. Clinical dynamic contrast-enhanced ultrasound image loops of liver tumors were also collected for preliminary validation of the in vitro findings. Time-intensity curves were extracted from image loops with two different approaches: from linearized log-compressed data and from linear (uncompressed) data. The error of time-intensity curve parameters derived from linearized log-compressed data (deviation from linear data) was found to be less than 2.1% and 5.4% for all studied parameters in the in vitro experiment and in the clinical study, respectively, when a high dynamic range setting (at least 50 dB on the iU22) is used. The gain must be carefully adjusted to ensure a high signal-to-noise ratio and to avoid signal saturation. From the time-intensity curve analysis it was also found that rise time of the bolus time-intensity curve is the least variable of all the studied time-intensity curve parameters. 相似文献
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