首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   24篇
  免费   0篇
  2008年   1篇
  2007年   1篇
  2006年   1篇
  1998年   1篇
  1997年   2篇
  1996年   2篇
  1995年   1篇
  1992年   1篇
  1991年   1篇
  1990年   1篇
  1988年   1篇
  1987年   1篇
  1983年   1篇
  1982年   2篇
  1979年   1篇
  1978年   3篇
  1976年   2篇
  1974年   1篇
排序方式: 共有24条查询结果,搜索用时 46 毫秒
1.
An intranuclear microsporidium is described from hemoblastic cells of the chinook salmon, Oncorhynchus tshawytscha. The infection is associated with an acute anemia in the fish. Up to 47% of the hemoblast nuclei were infected in anemic fish. The organisms, found only in spleen and kidney tissues, were 1–2 μm in diameter and consisted of vegetative and early sporulation forms. This microsporidium differs from known species which parasitize fish in its tissue location; however, the absence of mature spores and other life cycle stages precludes determination of its precise taxonomic identity.  相似文献   
2.
Routine audit of breast fine needle aspiration (FNA) cytology specimens and aspirator inadequate rates In an attempt to improve the quality of the breast FNA specimens we instigated a continuing audit of this procedure in this hospital. All FNAs since 1990 have had the following recorded: mode of aspiration, e.g. freehand or image guided, patient presentation (screening or symptomatic), patient diagnostic category, cytological diagnosis and final histological diagnosis. Aspirator performance was assessed by means of the inadequate aspiration rate (IR) of FNAs performed on patients with a final diagnosis of cancer (FDC) and diagnostic category A patients (clinically or radiologically malignant lesions). An ongoing annual review of the performance of all the aspirators was undertaken, all of whom received individual feedback. Counselling and further training were offered where indicated by poor performance. Over the period 1990–1995 a total of 13 537 FNAs were performed by 27 aspirators. The IR on category A and FDC cases over this period was 16.0% and 18.1%. The best performance achieved by an aspirator in a calendar year was an IR of 3.6% with no inadequate specimens in either FDC or category A lesions, and the best performance over the entire period was an average IR of 11.75% and 14.25% for FDC and category A groups, respectively. The overall IR on category A patients ranged from 15.9% to 23.8% and on FDC cases from 12.2% to 21.7%. There was a significant improvement in individual junior aspirator performance when their first year was compared with their last year on the unit. In some cases a deterioration in intra-aspirator performance was observed, from an IR of 6% to 33%. The overall IR rate of the unit remained stable for FDC patients, 15.5% in 1990 compared with 15.1% in 1995. This appeared to be largely due to a high proportion of the aspirations being performed by experienced personnel with consistent IRs. However, concealed within the overall rate there were some poor performers who benefited from counselling and/or further training. These results indicate an important role for audit in identifying poor aspirators who benefit from targeted training and advice, thereby improving the quality of FNA specimens, and ultimately patient care.  相似文献   
3.
M. P. HARRIS  S. WANLESS  D. A. ELSTON 《Ibis》1998,140(2):310-314
During 1993, about half the adult Shags Phalacrocorax aristotelis alive on the Isle of May, southeastern Scotland, failed to breed. The proportion not breeding was highest (66%) for individuals aged 14–21 years and lowest (12%) for those aged 3–6 years. In February 1994, a prolonged spell of onshore winds resulted in a wreck of these adults such that overwinter survival was reduced from the normal 88% to 14.7%. The age-specific pattern of survival over this winter differed from previous years, with birds aged less than 7 years and more than 16 years surviving less well and middle-aged individuals surviving better than expected. Whether an individual had bred or not in 1993 had little effect on the chances of survival of the youngest and oldest individuals, as most died. However, among Shags aged 12–15 years, those which had bred survived markedly less well than those which had not, indicating that there had been some cost involved to birds in breeding in 1993.  相似文献   
4.
In 1988, 985 patients presenting with breast disease, most with a palpable abnormality, were investigated by the triple approach (clinical examination, imaging and fine needle aspiration cytology [FNAC]). Using FNAC, 28% of patients were diagnosed as having carcinoma, 45% benign disease, 4% had suspicious cytology and 3% equivocal cytology. The remaining 20% had inadequate aspirates. Two false positive diagnoses of carcinoma were made (a false positive rate of 0.7%); one was a case of high grade non-Hodgkin's lymphoma and the other a papillary lesion with epithelial atypia. The false negative rate was 6.4%. Of these 49 patients, six had carcinoma-in-situ and 19 had low grade tumours. The absolute and complete sensitivities for the diagnosis of carcinoma in this series were 84.7% and 91.9% respectively and the absolute and complete specificities 99.7% and 98.3%, respectively. These figures compare favourably with those from other centres and confirm the efficacy of FNAC as part of the triple approach to the diagnosis of breast disease. The use of FNAC has resulted in a reduction in the number of Trucut and frozen section biopsies performed. Eighty three per cent of the patients with benign disease diagnosed by the triple approach have avoided excision biopsy, none of whom have subsequently been found to have carcinoma. Eighty patients with advanced breast carcinoma were spared operative intervention.  相似文献   
5.
The growth in area of the sixth leaf of field bean plants wasinvestigated in growth room experiments. Temperatures were variedduring the periods from appearance to unfolding and from unfoldingto full expansion. The effects on the duration of growth weregreater than those on absolute growth rates. Counts of epidermalcell number showed that the changes in final leaf area couldbe explained by changes in epidermal cell size for these temperaturesand these times of treatment. Epidermal cell number was notaffected by the treatments. Vicia faba, leaf expansion, temperature, growth, cell division  相似文献   
6.
KUMAR  A; ELSTON  J 《Annals of botany》1992,70(1):3-9
Various kinds of measurement of tissue water status were madeseveral times during water stress and recovery in Brassica juncea(cv Canadian Black) and B napus (cv Drakkar) Unstressed plantsof the two species had similar leaf water potentials (w), solute(s) and turgor potentials (p) Values of relative water content(RWC) and the slope of the linear relationship between p andRWC (p/RWC) were greater in B napus than in B juncea Statistical correlations of pooled data for the watered andstressed treatments differentiated the relationships among RWC,w and its components in the two species The major statisticaldifference was that p/RWC was related to RWC in B napus andto w and s in B juncea A decline in p/RWC with decreasing sin B juncea may be a mechanism for maintaining p at low soilwater potentials through maintenance of more elastic cell walls. Brassica juncea, Brassica napus, osmotic adjustment, tissue elasticity, water relations  相似文献   
7.
Cytological grading of breast carcinoma—a feasible proposition?   总被引:3,自引:0,他引:3  
Fine needle aspiration cytology (FNAC) of the breast is widely used in the diagnosis of breast carcinoma. In some centres this is sometimes the only diagnostic procedure performed prior to definitive treatment. A grading system based on cytology would be helpful in the selection of patients for appropriate therapy. The aim of this study, therefore, was to devise such a system for grading breast carcinoma based on cytological features alone. The features assessed were the degree of cell clustering, nuclear pleomorphism, nuclear diameter, the presence of multiple, easily visible nucleoli and necrosis. Cytological features were compared to the histological grade of the tumours following excision. Discriminant analysis showed that the features with the closest correlation with histological grade were nuclear diameter, nuclear pleomorphism and the presence of nucleoli. A scoring system based on these three parameters enabled the classification of tumours into high and low cytological grades which showed a close correlation with histological grade.  相似文献   
8.
Three experiments with five alternately-branched and one sequentially-branched cultivar of groundnuts are described. Spraying to control Cercospora leaf spot disease doubled the leaf area duration and increased the total weight of a plant by about 65 %. Spraying increased the weight of kernels per plant but in the alternately-branched cultivars also increased the weight of stem and leaves. The proportion of the total dry weight in the kernels in the alternate cultivars was hardly changed by spraying. The sequentially-branched cultivar gave the same increase in total dry weight when sprayed but spraying resulted in a larger increase in the dry weight of kernels. The sequentially-branched cultivar, with few initials for vegetative growth, did not give the same increase in leaf growth.  相似文献   
9.
A survey into the practice of fine needle aspiration cytology of the breast amongst members of the British Society for Clinical Cytology in 1990 and 1991 was performed. This paper presents their reported use of diagnostic categories in reporting and the criteria found useful in the diagnosis of benign and malignant disease. A wide variety of diagnostic categories are in use. the criteria used in diagnosis largely follow recommendations found in standard textbooks, but some less well recognized features were also suggested.  相似文献   
10.
The fate of all eggs laid by Guillemots Uria aalge in seven study areas on the Isle of May was recorded in 12 consecutive seasons. The average success at each site was related to its physical characteristics, bird density, position on the cliff and availability of suitable habitat for ticks. The numbers of neighbours and walls, type of site, slope where the egg was incubated and distance from the top of the cliff all had a significant effect on both hatching and breeding success. Potential tick habitat had no significant effect. Much variation in hatching and breeding success remained unexplained. Sites used when the colony was less than half its current size and most frequently in the period 1984–1995 were the most successful. Since an average Guillemot pair remains together at a site for only 3–4 years. the consistently high success of many sites over a period of 10–12 years suggests that the most used sites were occupied by a succession of high-quality birds.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号