全文获取类型
收费全文 | 40208篇 |
免费 | 2099篇 |
国内免费 | 142篇 |
专业分类
耳鼻咽喉 | 529篇 |
儿科学 | 2569篇 |
妇产科学 | 717篇 |
基础医学 | 4774篇 |
口腔科学 | 1119篇 |
临床医学 | 2917篇 |
内科学 | 7232篇 |
皮肤病学 | 1120篇 |
神经病学 | 2405篇 |
特种医学 | 1250篇 |
外科学 | 6050篇 |
综合类 | 1291篇 |
一般理论 | 17篇 |
预防医学 | 2021篇 |
眼科学 | 1439篇 |
药学 | 3992篇 |
1篇 | |
中国医学 | 349篇 |
肿瘤学 | 2657篇 |
出版年
2023年 | 329篇 |
2022年 | 972篇 |
2021年 | 1633篇 |
2020年 | 893篇 |
2019年 | 988篇 |
2018年 | 1390篇 |
2017年 | 1020篇 |
2016年 | 1345篇 |
2015年 | 1344篇 |
2014年 | 1982篇 |
2013年 | 2243篇 |
2012年 | 3163篇 |
2011年 | 3083篇 |
2010年 | 1851篇 |
2009年 | 1446篇 |
2008年 | 2068篇 |
2007年 | 2084篇 |
2006年 | 1906篇 |
2005年 | 1693篇 |
2004年 | 1570篇 |
2003年 | 1335篇 |
2002年 | 1145篇 |
2001年 | 773篇 |
2000年 | 707篇 |
1999年 | 592篇 |
1998年 | 265篇 |
1997年 | 212篇 |
1996年 | 218篇 |
1995年 | 184篇 |
1994年 | 154篇 |
1993年 | 131篇 |
1992年 | 349篇 |
1991年 | 335篇 |
1990年 | 357篇 |
1989年 | 329篇 |
1988年 | 285篇 |
1987年 | 241篇 |
1986年 | 234篇 |
1985年 | 228篇 |
1984年 | 174篇 |
1983年 | 123篇 |
1982年 | 68篇 |
1981年 | 75篇 |
1980年 | 69篇 |
1979年 | 109篇 |
1978年 | 71篇 |
1977年 | 87篇 |
1976年 | 65篇 |
1973年 | 62篇 |
1971年 | 61篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
S Kumar C J Harrison J Heighway H B Marsden D C West P M Jones 《International journal of cancer. Journal international du cancer》1987,40(4):499-504
A cell line (T3/73) from a Wilms' tumour has been established from a 9 month-old boy with aniridia. The tumour was removed in 1973. On histological examination a diagnosis of Wilms' tumour was made which showed undifferentiated areas, marked tubule formation and abundant striped muscle fibres. The tumour cells, which are fusiform, grew rapidly in culture without the addition of growth factors, and have undergone over 100 passages. Approximately 95% and 5% were positive for desmin and cytokeratin, respectively. The cell doubling time was 28 hr. Cytogenetic studies revealed a karyotype of 46,XY,del(11) (p12::p14). Although the cells stained very intensely with a monoclonal antibody that detects oncogene ras p 21 antigen, Southern blot analysis using c-Ha-ras as a probe failed to reveal an obvious deletion or amplification of either Ha-ras allele. 相似文献
62.
M Vaz M V Kumar D Rodrigues R N Kulkarni P S Shetty 《Journal of the autonomic nervous system》1991,36(3):201-208
Eight healthy, young adult males underwent three separate, 10-min 70 degrees head-up tilts (HUT) over a period of nine days, in order to assess the intra- and inter-individual variability of cardiovascular and plasma norepinephrine (NE) responses to the manoeuvre. Cardiovascular parameters and plasma NE were measured in the basal state and at 2-min intervals during the HUT. The results indicate that: (1) the intra-individual variability is a smaller component of the total variability of both cardiovascular and plasma NE responses to HUT; (2) the variability in cardiovascular parameters is smaller than that in plasma NE levels, both basal and in response to postural stress; (3) there does not appear to be any difference in variability when expressed either as the maximal or the mean response to HUT; and (4) there does not appear to be an increase in the variability of the measured parameters over the duration of the HUT. 相似文献
63.
64.
Interactions Between Cytomegalovirus, Human Herpesvirus-6, and the Recurrence of Hepatitis C After Liver Transplantation 总被引:1,自引:0,他引:1
Atul Humar Deepali Kumar Janet Raboud Angela M. Caliendo George Moussa Gary Levy Tony Mazzulli 《American journal of transplantation》2002,2(5):461-466
Recurrence of hepatitis C (HCV) following liver transplantation is common. Herpesvirus reactivation following transplant may have an immunomodulatory effect resulting in increased HCV replication. We studied whether cytomegalovirus (CMV) and human herpesvirus-6 (HHV-6) may be associated with HCV recurrence and viral load after transplant. We prospectively followed 66 HCV liver-transplant recipients with serial viral load testing for CMV and HHV-6. Infection and viral load were correlated with the development of biopsy-proven HCV recurrence and HCV viral loads. Histologic recurrence of HCV occurred in 41/66 (62.1%) patients. In the primary analysis, CMV infection and disease, and HHV-6 infection were not associated with HCV recurrence. Peak CMV and HHV-6 viral loads were not significantly different in patients with and without recurrence. No correlation was observed between HCV viral loads at 1 and 3 months post-transplant and peak HHV-6 or CMV viral loads. In a subgroup analysis, HHV-6 infection was associated with the development of more severe recurrence (hepatitis and/or fibrosis score > or = 2) (p = 0.01). Also, fibrosis scores at last follow up were higher in patients with CMV disease (1.67 vs. 0.56; p = 0.016) and in patients with HHV-6 infection (1.18 vs. 0.55; p = 0.031). In conclusion, HHV-6 and CMV infection and viral load were not associated with increased overall rates of HCV recurrence or HCV viral load after liver transplantation but may be associated with more severe forms of recurrence. 相似文献
65.
A study of DNA content by flow cytometry revealed a significant difference between rhabdomyosarcomas, which were mainly non-diploid, and other sarcomas of children which were mainly diploid (p = 0.01). There was no association between DNA ploidy and survival or aggressive behaviour of the tumour as indicated for example by advanced clinical stage or unfavourable histology. While DNA ploidy correlated with age, it did not correlate with any other clinical characteristic. The apparent lack of prognostic value of DNA content may have been masked by some high CV values and overridden by the effect of chemotherapy which was the most significant variable in determining a patient's survival (p = 0.00005). 相似文献
66.
N. C. Sharma R. Bhatia S. Singh P. C. John S. Kumar H. Singh 《Epidemiology and infection》1994,112(1):45-49
A total of 675 strains of Salmonella bareilly received from different parts of India and France during 1959-92 were phage typed using six bacteriophages. Overall typability achieved was 90.8% with 23 distinct phage types excluding a group of untypable strains. Phage types have been defined in octal code. Simpson''s coefficient was applied for diversity index having a value of 0.839. This system was found to be reproducible, stable and epidemiologically useful. 相似文献
67.
P Kumar S K Rastogi B N Gupta T Husain 《The Journal of the Society of Occupational Medicine》1991,41(4):157-160
Behavioural studies were conducted on a random sample of 38 glass bangle workers engaged in various occupations and exposed to high ambient temperature (38.2 +/- 3.4 degrees C) and radiant heat (46.2 +/- 5.1 degrees C) during their work in the glass bangle industries at Firozabad, India. Twenty-two control subjects of similar age and socio-economic status unexposed to heat during their work were also studied for comparison. The digit span test, digit symbol test, Bourdon-Wiersma vigilance test, flicker fusion test and Maudsley personality inventory (MPI) were used to assess the behavioural changes induced by the existing heat stress. The mean scores of immediate memory were much lower in the exposed population than in the controls thereby indicating impairment of immediate memory in the study group. The visuo-motor coordination and vigilance were also significantly affected. Visual perception showed a downward trend among the glass bangle workers, although the MPI test indicated no personality changes. 相似文献
68.
A K Rama Krishna Shivanand Patil Grs Srinivas Rao Ajit Kumar 《Indian journal of gastroenterology》2006,25(2):97-98
Gastrointestinal manifestations of dengue fever are mainly in the form of bleeding or liver function abnormalities. Dengue fever presenting as acute colitis-like picture is not reported to date. We report a 50-year-old man with dengue fever presenting with lower gastrointestinal bleeding and colonoscopic features of acute inflammatory colitis. 相似文献
69.
M Devi S Nalin Kumar K Ranganathan T R Saraswathi 《Indian journal of dental research》2004,15(4):149-151
Intravascular papillary endothelial hyperplasia (IPEH) is an unusual vascular lesion of proliferating endothelial cells. It is more frequently seen in the extremities, particularly in the fingers. Oral IPEH has been reported with the common sites being lip, tongue, and buccal mucosa. In this article, we present a case of oral IPEH of the floor of the mouth, an unusual location, presenting in a 9-month-old male. The histogenesis, histologic features, and ultrastructural features are also reviewed. A misdiagnosis of angiosarcoma can be made in a case of IPEH due to similar histopathologic features. It is imperative to rule out this error by an elaborate histopathologic evaluation ofthese lesions. 相似文献
70.