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1.
肺癌在中国恶性肿瘤的发病率位居第一,随着低剂量薄层CT在肺癌筛查中的广泛应用,临床发现更多表现为非完全实性结节的肺腺癌,目前众多研究使CT影像学特征和肺腺癌病理的关系得到更进一步的认知,虽然CT能对部分非完全实性结节做出定性和定位诊断,但仍有部分非完全实性结节诊断困难,PET-CT结合了病灶的代谢信息和精确的定位信息,从而提高对肺部结节诊断的敏感性、特异性、准确性,综合多个文献PET-CT在非完全实性结节中的诊断分期价值较CT无明显提升,却在评估预后和制定合适手术方案上可以起到一定的作用,本文就PET-CT在SSN中的应用价值进行阐述。  相似文献   
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The size and immunological reactivity of the primary gene products of a small non-aggregating dermatan sulfate proteoglycan from bovine and monkey arterial smooth muscle cells were examined after cell-free translation of mRNA. Antisera against the dermatan sulfate proteoglycans from bovine articular cartilage, DSPG II [Rosenberg et al. J. Biol. Chem. 260, 6304 (1985)] and human skin fibroblasts [Glossl et al. J. Biol. Chem. 259, 14144 (1984)] were used to show that the unmodified smooth muscle precursor core protein was immunologically related to both the cartilage and fibroblast core proteins. The size of the precursor core proteins within each species was identical regardless of the tissue source. Comparison of the precursor core proteins synthesized by primate and bovine cells revealed that the bovine core proteins were approximately 1500 Da larger than the primate core proteins as determined by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis. A similar size difference was observed when the mature core proteins of monkey smooth muscle cells and bovine articular chondrocytes were compared after removal of the glycosaminoglycan chains. These results indicate that arterial smooth muscle cells synthesize a dermatan sulfate proteoglycan whose core protein is similar to, if not the same as, the cartilage and fibroblast dermatan sulfate proteoglycan core proteins. These core proteins may be encoded by the same gene that has diverged in size during speciation.  相似文献   
3.
烟青虫感染核型多角体病毒后围食膜的病变   总被引:4,自引:1,他引:3  
邓塔  蔡秀玉 《昆虫学报》1992,35(1):123-124
昆虫的围食膜是衬在昆虫中肠内一种网状的结构,它可充作虫体抵御外来病原侵染的一道屏障。关于鳞翅目昆虫幼虫感染了昆虫病毒后围食膜的病变问题,国内外鲜有报道。尤锡镇和康慧娟(1985)曾以实验证明家蚕围食膜对核型多角体病毒有灭活作用,而且认为核型多角体病毒不能侵染和破坏围食膜。Derksen和Granados(1988)则证明染病幼虫的围食膜因不同杆状病毒(包括两种核型多角体病  相似文献   
4.
Sandell M  Agrell J  Erlinge S  Nelson J 《Oecologia》1990,83(2):145-149
Summary In a sample of 240 juvenile field voles 8% of the males and 22% of the females reached sexual maturity within their natal home range. Among individuals retrapped as adults, 58% of males and 23% of females had dispersed, i.e. had moved more than one home range diameter. The mean distance moved for males (58.5 m) exceeded that for females (28.6 m). Male movement distances were negatively associated with total density, and with density of adult females, but not with male density. Female movements were not related to population density. There were no relation between sex ratio and distance moved. The distribution of distances moved for both males and females fit a geometrical distribution, suggesting the importance of competitive processes.  相似文献   
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Objectives Somatoform disorders are common in international primary care settings, but have been little studied in the developing world. The objective of this study was to determine the prevalence of severe undifferentiated somatoform disorder, and its relationship to depression and anxiety, among patients attending walk-in clinics in Trinidad.Methods The study participants, who were all aged 18 years or older and attending walk-in clinics at 16 randomly selected health centres, were surveyed between May and August 2007 using the PRIME-MD questionnaire.Results There were 594 participants (the response rate was 92%), of whom 72.7% were female. Their ages ranged from 18 to 93 years, and 54.5% were over 50 years of age. In total, 37.2% were married and 25.9% were single. Indo-Trinidadians represented 43.1% and Afro-Trinidadians represented 36% of the study sample; 56.5% of the participants reported that their income was less than US$ 400 per month, and 65.7% were unemployed. At walk-in clinics in Trinidad, the estimated prevalence of severe undifferentiated somatoform disorder was 10.3% (95% CI: 7.86–12.74), that of hypochondriasis was 28.5% (95% CI: 24.9–32.1), and that of body dysmorphic disorder was 15.8% (95% CI: 11.9–18.7). Severe undifferentiated somatoform disorder was statistically significantly associated with gender and ethnicity but not with age, level of education, employment status or income. Chi-square testing found significant associations between the presence of severe undifferentiated somatoform disorder and both depression and anxiety (P < 0.05), between hypochondriasis and both anxiety and depression (P < 0.05), and between body dysmorphic disorder and depression (P < 0.05) but not anxiety. Regression analysis suggested that the demographic features that predicted severe undifferentiated somatoform disorder were being female or Indo-Trinidadian.Conclusions Walk-in clinics in Trinidad that serve older patients on a lower income have a high proportion of patients with somatoform disorders as measured by the PRIME-MD scale. These patients exhibit many features of anxiety and depression. These findings have implications for medical training and service delivery.  相似文献   
8.
In many bird species, there is a floating population of females that are excluded from breeding because of competition for limited breeding resources. Female floaters may enhance their reproductive success by engaging in intraspecific brood parasitism. We studied female floaters in a population of European starlings, Sturnus vulgaris, in order to determine their identity and potential parasitic behaviour. Females were caught after being attracted to nestboxes with artificial nests during 1993-1995. None of the females was known to have a nest of her own at capture but 47% of the females either laid an egg in the nest or carried a fully developed egg within the reproductive tract, indicating that they were intraspecific brood parasites. The floating females were significantly younger and smaller than breeding females. Of 13 females equipped with radiotransmitters and followed daily, all but one started a breeding attempt of their own after 3-8 days and the majority settled as secondary females or mated with males where the original female had disappeared. This suggests that females that are unable to compete successfully for nest sites or males early in the breeding season may use intraspecific brood parasitism to enhance reproductive success during the period that they are constrained from breeding. The importance of settling rapidly because of a seasonal decline in reproductive success may also promote the evolution of intraspecific brood parasitism in the starling. The relative reproductive success of combining egg dumping with breeding compared with traditional breeding will depend on the costs of delaying breeding as well as the probability of finding a mate later in the breeding season. Copyright 1999 The Association for the Study of Animal Behaviour.  相似文献   
9.
The processes of apoptosis and epithelial-mesenchymal transformation have been identified as two major mechanisms by which secondary palatal shelves achieve fusion. The aim of this study was to investigate alterations in these mechanisms by changing the physical distance between paired palatal shelves in an in vitro model of palatogenesis. Wild-type palatal pairs were dissected from E13.5 CD1 mouse embryos and allowed to grow in tissue culture for 48 hours at various intershelf distances. During the fusion process, medial edge epithelial cell fate was assessed using terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) staining, to evaluate apoptosis, and carboxyfluorescence (carboxy-2,7'-dichlorofluorescein diacetate succinimidyl ester) labeling, to measure transformation to mesenchymal cells. Palatal pairs separated in culture greater than or equal to 0.4 mm failed to fuse. TUNEL staining showed that the number of apoptotic cells in the palatal shelves increased as the intershelf distance increased, becoming marked in shelves that did not achieve fusion. The amount of epithelial-mesenchymal transformation, however, decreased with increasing intershelf distance. These results suggest that the contribution of epithelial-mesenchymal transformation and apoptosis to palatal shelf development and fusion can be altered by physical proximity. Therefore, one mechanism behind clefting in utero may result from an imbalance in epithelial-mesenchymal transformation and apoptosis as observed in vitro where palatal shelves are challenged to fuse by physical separation. This effect could be significant in the understanding and treatment of developmental palatal abnormalities. Perhaps in utero manipulation of intershelf spacing or epithelial-mesenchymal transformation and/or apoptosis could reverse the clefting paradigm.  相似文献   
10.
5-Methyl-6-nitroquipazine, a novel analogue of the potent and selective serotonin transporter inhibitor 6-nitroquipazine was synthesized and radiolabeled with tritium and the positron emitter carbon-11. [3H]5-methyl-6-nitroquipazine was found to have a Kd=51±7 pM. The high affinity and the facile labeling of [11C]5-methyl-6-nitroquipazine makes it a promising radioligand for visualization of the serotonin transporter with positron emission tomography.  相似文献   
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