全文获取类型
收费全文 | 1176篇 |
免费 | 260篇 |
国内免费 | 20篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 25篇 |
妇产科学 | 29篇 |
基础医学 | 285篇 |
口腔科学 | 4篇 |
临床医学 | 113篇 |
内科学 | 322篇 |
皮肤病学 | 11篇 |
神经病学 | 70篇 |
特种医学 | 100篇 |
外科学 | 125篇 |
综合类 | 44篇 |
预防医学 | 140篇 |
眼科学 | 8篇 |
药学 | 84篇 |
1篇 | |
肿瘤学 | 91篇 |
出版年
2021年 | 15篇 |
2019年 | 12篇 |
2018年 | 16篇 |
2017年 | 10篇 |
2016年 | 12篇 |
2015年 | 20篇 |
2014年 | 20篇 |
2013年 | 26篇 |
2012年 | 45篇 |
2011年 | 51篇 |
2010年 | 20篇 |
2009年 | 32篇 |
2008年 | 55篇 |
2007年 | 83篇 |
2006年 | 56篇 |
2005年 | 78篇 |
2004年 | 55篇 |
2003年 | 56篇 |
2002年 | 36篇 |
2001年 | 44篇 |
2000年 | 57篇 |
1999年 | 32篇 |
1998年 | 27篇 |
1997年 | 18篇 |
1996年 | 26篇 |
1995年 | 11篇 |
1994年 | 24篇 |
1993年 | 16篇 |
1992年 | 39篇 |
1991年 | 35篇 |
1990年 | 26篇 |
1989年 | 38篇 |
1988年 | 49篇 |
1987年 | 36篇 |
1986年 | 31篇 |
1985年 | 38篇 |
1984年 | 25篇 |
1983年 | 23篇 |
1982年 | 11篇 |
1981年 | 14篇 |
1980年 | 19篇 |
1979年 | 18篇 |
1978年 | 9篇 |
1977年 | 7篇 |
1976年 | 6篇 |
1975年 | 10篇 |
1973年 | 6篇 |
1972年 | 14篇 |
1971年 | 8篇 |
1970年 | 4篇 |
排序方式: 共有1456条查询结果,搜索用时 15 毫秒
11.
Christopher A Pierce George Jewell Mark Mennemeier 《Journal of the International Neuropsychological Society》2003,9(1):72-78
Psychophysical functions are used to characterize both normal perception and altered perception among patients with neglect, yet the reliability of these functions is rarely examined. The present study examined two-week, test-retest reliability for power functions derived from line bisection data among 58 normal, young and old, male and female subjects. Power function exponents and constants were, at best, moderately reliable over time. The size of the exponent tended to decrease at retesting. Reliability coefficients varied by age and gender; they were highly significant for young men, marginally significant for older men, and non-significant for women. Race influenced reliability as coefficients were significant for Caucasian subjects but not for African American subjects. Age and gender effects in this study parallel those in the literature on pseudoneglect, and they may reflect hemispheric differences in visuo-spatial processing, magnitude estimation, or both. 相似文献
12.
13.
Extensive intraductal component (EIC) has been reported to have a prominent role in local recurrence after treatment of early-stage breast cancer with lumpectomy and irradiation. Pathologic specimens from 250 breasts (245 patients) treated between June 1982 and June 1990 with lumpectomy, immediate (boost) interstitial iridium-192 to 15-20 Gy, and external-beam irradiation to the entire breast to 45-50 Gy were reviewed. EIC was present in 61 breasts. At a median follow-up period of 58 months (range, 14-110 months), there were 10 recurrences in the 250 treated breasts. Of these 10, three were in patients from the group with EIC. The 10-year actuarial recurrence rates in breasts with and without EIC were 9.1% and 5.2%, respectively. The difference between the two rates was not significant. If an immediate boost with interstitial iridium is used in therapy, the influence of EIC on local failure is insignificant. 相似文献
14.
15.
16.
Localization of a gene for otosclerosis to chromosome 15q25-q26 总被引:5,自引:0,他引:5
Tomek MS; Brown MR; Mani SR; Ramesh A; Srisailapathy CR; Coucke P; Zbar RI; Bell AM; McGuirt WT; Fukushima K; Willems PJ; Van Camp G; Smith RJ 《Human molecular genetics》1998,7(2):285-290
Among white adults otosclerosis is the single most common cause of hearing
impairment. Although the genetics of this disease are controversial, the
majority of studies indicate autosomal dominant inheritance with reduced
penetrance. We studied a large multi- generational family in which
otosclerosis has been inherited in an autosomal dominant pattern. Five of16
affected persons have surgically confirmed otosclerosis; the remaining nine
have a conductive hearing loss but have not undergone corrective surgery.
To locate the disease- causing gene we completed genetic linkage analysis
using short tandem repeat polymorphisms (STRPs) distributed over the entire
genome. Multipoint linkage analysis showed that only one genomic region, on
chromosome 15q, generated a lod score >2.0. Additional STRPs were typed
in this area, resulting in a lod score of 3.4. STRPs FES (centromeric) and
D15S657 (telomeric) flank the 14. 5 cM region that contains an otosclerosis
gene.
相似文献
17.
Effect of fixatives and tissue processing on the content and integrity of nucleic acids 总被引:21,自引:0,他引:21 下载免费PDF全文
Clinical and molecular medicines are undergoing a revolution based on the accelerated advances in biotechnology such as DNA microarrays and proteomics. Answers to fundamental questions such as how does the DNA sequence differ between individuals and what makes one individual more prone for a certain disease are eagerly being sought in this postgenomic era. Several government and nonprofit organizations provide the researchers access to human tissues for molecular studies. The tissues procured by the different organizations may differ with respect to fixation and processing parameters that may affect significantly the molecular profile of the tissues. It is imperative that a prospective investigator be aware of the potential contributing factors before designing a project. The purpose of this review is to provide an overview of the methods of human tissue acquisition, fixation, and preservation. In addition, the parameters of procurement and fixation that affect the quality of the tissues at the molecular level are discussed. 相似文献
18.
19.
K M Miner C L Manyak E Williams J Jackson M Jewell M T Gammon C Ehrenfreund E Hayes L T Callahan rd H Zweerink et al. 《Infection and immunity》1986,52(1):56-62
Results show that various inbred strains of mice can be segregated into two distinct groups, based on their capacity to allow a number of nontuberculous mycobacterial infections to grow in target organs following experimental intravenous infection. The first group, which allowed these infections to grow progressively, was thus designated as naturally susceptible to these infections; in contrast, those strains which were able to exert detectable bacteriostasis were designated as naturally resistant. It was then found that segregation of mouse strains based on this distinction also mirrored the capacity of these animals to generate acquired immunity to the mycobacterial infections. For example, Mycobacterium simiae grew progressively in susceptible C57BL/6 mice, subsequently triggering acquired mechanisms of immunity, whereas no evidence for acquired immunity could be found in resistant A/Tru mice infected with this organism. The possibility that acquired immunity could not be expressed in the latter strain as a result of a defect in macrophage activation was excluded. Moreover, it was found that the trait of resistance to these infections could be transferred by bone marrow cells into radiation chimeras, thus indicating that this trait was expressed by the progeny of hemopoietic precursor cells. Subsequent backcross analysis to determine the mode of inheritance of the trait of resistance to these mycobacterial infections revealed data that were consistent with the hypothesis that this resistance is controlled by more than one gene. Statistical analysis of the data by the maximum likelihood method suggested polygenic control, although in some cases the probability values suggested control by a major gene, influenced by modifier genes. These findings suggest that the previous hypothesis that the growth of mycobacterial infections in inbred strains of mice is controlled by a single gene should be reevaluated. 相似文献
20.
The osteoclast-type giant cell tumor of the pancreas 总被引:1,自引:0,他引:1
R C Berendt T K Shnitka E Wiens V Manickavel L D Jewell 《Archives of pathology & laboratory medicine》1987,111(1):43-48
We present a case report of osteoclast-type giant cell tumor of the pancreas and review the literature concerning this rare neoplasm, the histogenesis of which is uncertain. Electron microscopic features have suggested stromal, histiocytic, and epithelial origins to different investigators. Analysis of the present case supports and epithelial origin, with positive immunocytochemical staining for carcinoembryonic antigen and for low molecular weight keratin in the mononuclear and in some osteoclastlike giant cells. These tumor cells did not stain for mesenchymal markers (lysozyme, alpha 1-antitrypsin, alpha 1-antichymotrypsin, S100 protein). Zymogen granules, desmosomes, and zonulae occludentes were identified ultrastructurally and further support an epithelial derivation. 相似文献