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1.
Carotid and vertebral artery dissections typically occur in young adults after major trauma, although they can arise spontaneously or after trivial injury. Many patients with carotid dissections have minor symptoms such as a subject bruit or Horner's syndrome. Cephalic pain is also frequent and often inaugural in carotid dissection. However, extracranial dissection is a well recognised cause of ischaemic stroke. The diagnosis of dissection was based on angiographic findings. Noninvasive imaging also allows prompt and reliable diagnosis. Our goal was to demonstrate the spectrum of neuroradiologic (CT, MR and angiographic) findings in craniocervical arterial dissection and compare the diagnostic utility of CT, MR, MR angiography. Clinical data imaging studies, and outcome were reviewed and compared with the results in four patients with carotid artery dissection.  相似文献   
2.
In this work, real-time ultraviolet photodetectors are realized through metal–semiconductor–metal (MSM) structures. Amorphous indium gallium zinc oxide (a-IGZO) is used as semiconductor material and gold as metal electrodes. The readout of an individual sensor is implemented by a transimpedance amplifier (TIA) consisting of an all-enhancement a-IGZO thin-film transistor (TFT) operational amplifier and a switched capacitor (SC) as feedback resistance. The photosensor and the transimpedance amplifier are both manufactured on glass substrates. The measured photosensor possesses a high responsivity R , a low response time t R E S , and a good noise equivalent power value NEP .  相似文献   
3.
We report on the experimental realization of an ultrahigh vacuum (UHV) indium sealing between a conflat knife edge and an optical window. The sealing requires a very low clamping force and thus allows for the use of very thin and fragile windows.  相似文献   
4.
Formulation effects on the distribution of pigment particles in paints   总被引:2,自引:0,他引:2  
Modern water-borne paints are widely used in different areas of applications ranging from high-gloss lacquers to flat, scrub-resistant interior paints. From this point of view, the pigment volume concentration (PVC) is one key-parameter adjusting the desired application properties. In high-gloss paints, for example, a low PVC is required to accommodate the proper surface roughness to achieve a high gloss. Consequently, a high concentration of TiO2 is needed to obtain a good hiding power at the same time. Flat paints nonetheless are highly filled due to cost reasons preferentially by CaCO3 and the pigment binding capacity of the binder is crucial. In this work, paint formulations differing in PVC, and the type of binder or dispersing agent were investigated by various techniques concerning the distribution and aggregation of pigment particles, e.g. TiO2. To get a detailed insight into the structure of the liquid paints and the corresponding dried paint films, suitable analytical tools were applied for characterization. The structure of the liquid paints was analyzed by remission light spectroscopy (RLS), disc centrifugation, cryogenic-replication transmission electron microscopy (Cryo-replica TEM) and cryogenic-scanning electron microscopy (Cryo-SEM). The pigment distribution in the corresponding dried paint films was examined by means of atomic force microscopy (AFM), TEM and RLS. The tendency of the TiO2-pigments to form aggregates was found to depend on both: first on the type of binder used in the formulation and second on the employed dispersing agent. It is shown that only by adjusting the properties of the binder in combination with common dispersants, it is possible to get well-distributed TiO2 particles within the paint. Correlation of application properties, e.g. gloss and blocking to the microscopic structure is presented.  相似文献   
5.
The aim of this study was to determine whether suckling-induced prolactin (PRL) levels were modified when milk ejection was impaired. Milk ejection impairment was achieved in two experimental models: a) depriving the dam of sleep during suckling and b) increasing the nonsuckling intervals in lactating dams. Sleep deprivation blocked milk ejection and enhanced suckling-induced PRL levels in dams that had been previously separated from their pups. When milk ejection is blocked in litter-deprived dams, mammary glands are not evacuated and they remain engorged. Suckling stimuli were not the cause of the difference in suckling-induced serum PRL levels in control and sleep-deprived dams. The engorgement of the mammary glands may play a role, as a maximum suckling-induced PRL increase was not observed in nonseparated SD dams with nonengorged mammary glands. Moreover, suckling-induced PRL levels were decreased when engorged mammary glands of SD dams were evacuated through an oxytocin injection. A parallel increase between suckling-induced PRL levels and mammary gland weight was observed in the experiments in which milk ejection was impaired through an increase in the intervals of nonsuckling, providing additional support for a relationship between mammary gland engorgement and the regulation of suckling-induced PRL levels.  相似文献   
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7.
Aortoenteric fistula represents a communication between aortic and duodenal lumen. It is a very rare complication of aortic aneurysmal disease as well as aortic prosthetic surgery. There are only few surgeons who have seen more than one case of aortoenteric fistula. At the Institute of Surgery one case of aortoenteric fistula was treated. It was well diagnosed at the Institute for Internal Medicine, and then presented to the vascular surgeon who operated immediately. The whole diagnostic and therapeutic procedure was well done, but stenosing carcinoma of ascendent colon was found during the operation. Resection were done leading to the dehiscence of bowel anastomosis and fatal outcome for the patient. This case is instructive in a diagnostic and surgical manner.  相似文献   
8.
An optimization based algorithm for designing phase-shifting masks is proposed. The approach is an extension of the previous work in the sense that the intensity image is optimized at a number of optical planes rather than just the focus plane. In addition, the algorithm can be used to design masks with shifted focus plane and/or extended depth of focus. The concept of a dual mask is introduced, and its consequences for practical phase-shifting mask design are shown. The proposed design techniques are applied to single line phase connectors, cross phase connectors, contact holes and bright lines. Simulation and experimental results verify the capability of the design technique for extending depth of focus and shift the focus plane  相似文献   
9.
This study examines the influence of five communication modalities on voters' perceptions of candidates during what Popkin terms 'the distant phase' of the presidential primary campaign. During the final week of the New Hampshire primary campaign, researchers surveyed 315 prospective votes in four states whose primaries followed New Hampshire's by 1, 2, 4, and 5 weeks. The results revealed that political talk radio exerted the greatest influence on voters' perceptions of Bob Dole and considerable impact on perceptions of Steve Forbes. In addition, prospective voters' conversations with other people, television news, and candidate spots (only for Forbes) exerted modest influence on voters' perceptions of Republican candidates.  相似文献   
10.
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