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[Structure: see text] The versatility of supramolecular chemistry has been exploited in constructing nanovalves based on mesoporous silica MCM-41 and the mutual recognition between secondary dialkylammonium ions and dibenzo[24]crown-8 (DB24C8). Naphthalene-containing dialkylammonium threads were tethered to the MCM-41, followed by loading with coumarin 460 and capping with DB24C8. Controlled release of coumarin 460 from the pores of MCM-41 was demonstrated using different bases. The rate of release of coumarin 460 from the nanovalves depends on the size of the base.  相似文献   
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Currently, magnetic resonance (MR) is most useful as a means of providing distinct images of gross abnormalities in major blood vessels. While new advances and further refinements will continue, MR has proven its value as a convenient and effective diagnostic tool for the recognition and delineation of vascular abnormalities, such as acquired arteriovenous fistulae (AVFs). We report a case of a chronic, post-traumatic AVF, in which MR angiography provided excellent anatomic detail and angiographic correlation.  相似文献   
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A structural failure problem was solved using an integrated and iterative program of testing and analysis. The steps taken in solving the problem were: analytical calculations; operational testing; qualifications of analytical results; problem identification; design of corrective action; and confirmatory testing.  相似文献   
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Breast cancer (BC) is one of the most common cancers and one of the most common causes for cancer-related mortality. Discovery of protein biomarkers associated with cancer is considered important for early diagnosis and prediction of the cancer risk. Protein biomarkers could be investigated by large-scale protein investigation or proteomics, using mass spectrometry (MS)-based techniques. Our group applies MS-based proteomics to study the protein pattern in human breast milk from women with BC and controls and investigates the alterations and dysregulations of breast milk proteins in comparison pairs of BC versus control. These dysregulated proteins might be considered potential future biomarkers of BC. Identification of potential biomarkers in breast milk may benefit young women without BC, but who could collect the milk for future assessment of BC risk. Previously we identified several dysregulated proteins in different sets of human breast milk samples from BC patients and controls using gel-based protein separation coupled with MS. Here, we performed 2D-PAGE coupled with nano-liquid chromatography–tandem MS (nanoLC-MS/MS) in a small-scale study on a set of six human breast milk pairs (three BC samples vs. three controls) and we identified several dysregulated proteins that have potential roles in cancer progression and might be considered potential BC biomarkers in the future.  相似文献   
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Demonstration of aortic lesions via cine magnetic resonance imaging   总被引:1,自引:0,他引:1  
Cine-MRI was used to evaluate eight patients with known thoracic aorta disease. Included in this study were three aortic coarctations, two aortic dissections, an aneurysm, a posttraumatic pseudoaneurysm, and a patent ductus arteriosus. Cine-MRI was found to be valuable in the assessment of the pathologic anatomy and associated flow disturbances in these disorders. In seven cases, the images demonstrated the aortic lesion and aberrant blood flow. Our technique was unable to image the structural lesion in the patient with patent ductus arteriosus, but the abnormal blood flow was shown. Angiographic data were available on three of the cases to confirm the MR findings. The MRI images were obtained in axial, coronal, sagittal, and oblique planes using fast field echo acquisition technique of cine-MRI. We found the additional data or benefits provided by cine-MRI, when compared to cardiac gated spin echo images, to be most advantageous in the cases of aortic coarctation and dissection only.  相似文献   
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