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排序方式: 共有1395条查询结果,搜索用时 15 毫秒
991.
992.
Dorfman GS; Cronan JJ; Paolella LP; Lambiase RE; Haas RA; Scola FH; Schepps B 《Radiology》1989,173(1):159-162
To determine the prevalence of iatrogenic abnormalities associated with percutaneous delivery of Greenfield filters, the authors prospectively evaluated 69 peripheral veins used for filter placement in 68 patients. Of the 69 venotomy sites, 63 were not associated with preexisting thrombosis and were evaluated with compression and Doppler ultrasound within 1 week of placement and over 13-541 days. New thrombosis developed at the puncture site in nine of 63 sites (14.3%), although clinical suspicion of clot was raised in only one patient. Fifty-four sites (85.7%) showed no evidence of acute deep venous thrombosis, even though three patients had signs and symptoms suggestive of thrombosis. During the follow-up, most new thromboses resolved, yielding a 96.3% long-term patency rate. The authors conclude that postplacement increase in symptoms of venous stasis and occlusion may not correlate with placement site thrombosis. New filters should be evaluated for their ability to capture potential pulmonary emboli while maintaining caval patency and for mechanical and biologic stability because placement site complications occur at low rates and resolve in most cases. 相似文献
993.
A 26-year-old woman had an infiltrative renal lesion accompanied by massive regional lymphadenopathy. Biopsy of the renal mass and a coexistent orbital mass revealed identical histologic evidence of sinus histiocytosis. This unusual benign entity is uncommon in the kidney, but radiographically, it may closely simulate an infiltrative renal neoplasm, especially a lymphoma or leukemia or even renal cell carcinoma. 相似文献
994.
C.M. LAPIÈRE 《The British journal of dermatology》1990,122(S35):5-11
995.
Eric James Blown John Kirkland Claire McLachlan-Smith Jan McPherson Bill Anderson 《Early child development and care》1990,55(1):67-74
Are we alone in the Universe or are we but one of many advanced technical civilizations? Assuming that we are not alone and wished to make contact with our galactic neighbours how could we do so? When humans communicate, meaning comes from written and verbal language embedded in metaphor. However, the public nature of metaphoric language reduces the personal essence of individual experience during translation into words. The delusion of shared metaphor being obtained through written and verbal language distorts our views of reality, it impairs our ability to empathise with others, and it disharmonizes our attempts to attune to any invariants and affordances of universal language. This paper attempts to identify some of the elements of universal language and probes the limitations of the communication metaphor as a way of empathising between humans and other intelligent life. Our investigation suggests that if Communication with Extraterrestrial Intelligence (CETI) is to become realised then a new paradigm for human empathising based on human ethology and nonverbal, non-metaphoric language, embracing the Eastern awareness of wholeness is required to replace the current Western paradigm with its dependence on words and transfer. 相似文献
996.
997.
Tobacco smoke contains a range of toxins including carbon monoxide and cyanide. With specialized cells and high metabolic demands, the optic nerve and retina are vulnerable to toxic exposure. We examined the possible effects of smoking on color vision: specifically, whether smokers perceive a different pattern of suprathreshold color dissimilarities from nonsmokers. It is already known that smokers differ in threshold color discrimination, with elevated scores on the Roth 28-Hue Desaturated panel test. Groups of smokers and nonsmokers, matched for sex and age, followed a triadic procedure to compare dissimilarities among 32 pigmented stimuli (the caps of the saturated and desaturated versions of the D15 panel test). Multidimensional scaling was applied to quantify individual variations in the salience of the axes of color space. Despite the briefness, simplicity, and "low-tech" nature of the procedure, subtle but statistically significant differences did emerge: on average the smoking group were significantly less sensitive to red-green differences. This is consistent with some form of injury to the optic nerve. 相似文献
998.
999.
1000.
Niacin and carcinogenesis 总被引:3,自引:0,他引:3
Kirkland JB 《Nutrition and cancer》2003,46(2):110-118
The dietary status of niacin (vitamin B3) has the potential to influence DNA repair, genomic stability, and the immune system, eventually having an impact on cancer risk, as well as the side effects of chemotherapy in the cancer patient. In addition to its well-known redox functions in energy metabolism, niacin, in the form of NAD, participates in a wide variety of ADP-ribosylation reactions. Poly(ADP-ribose) is a negatively charged polymer synthesized, predominantly on nuclear proteins, by at least seven different enzymes. Poly(ADP-ribose) polymerase-1 (PARP-1) is responsible for the majority of polymer synthesis and plays important roles in DNA damage responses, including repair, maintenance of genomic stability, and signaling events for stress responses such as apoptosis. NAD is also used in the synthesis of mono(ADP-ribose), often on G proteins, with poorly understood roles in signal transduction. Last, NAD and NADP are required for the synthesis of cyclic ADP-ribose and nicotinic acid adenine dinucleotide (NAADP), two mediators of intracellular calcium signaling pathways. Disruption of any of these processes has the potential to impair genomic stability and deregulate cell division, leading to enhanced cancer risk. There are various sources of evidence that niacin status does have an impact on cancer risk, including animal models of leukemogenesis and skin cancer, as well as epidemiological data from human populations. 相似文献