全文获取类型
收费全文 | 1335288篇 |
免费 | 100355篇 |
国内免费 | 4285篇 |
专业分类
耳鼻咽喉 | 16797篇 |
儿科学 | 43581篇 |
妇产科学 | 36356篇 |
基础医学 | 197858篇 |
口腔科学 | 35902篇 |
临床医学 | 129551篇 |
内科学 | 258143篇 |
皮肤病学 | 26371篇 |
神经病学 | 111859篇 |
特种医学 | 48169篇 |
外国民族医学 | 366篇 |
外科学 | 184043篇 |
综合类 | 28863篇 |
现状与发展 | 1篇 |
一般理论 | 460篇 |
预防医学 | 114363篇 |
眼科学 | 29005篇 |
药学 | 98856篇 |
6篇 | |
中国医学 | 3199篇 |
肿瘤学 | 76179篇 |
出版年
2021年 | 10926篇 |
2019年 | 11662篇 |
2018年 | 16325篇 |
2017年 | 12293篇 |
2016年 | 13261篇 |
2015年 | 15206篇 |
2014年 | 20820篇 |
2013年 | 32047篇 |
2012年 | 44232篇 |
2011年 | 46879篇 |
2010年 | 27071篇 |
2009年 | 24919篇 |
2008年 | 42707篇 |
2007年 | 45047篇 |
2006年 | 45160篇 |
2005年 | 43582篇 |
2004年 | 41553篇 |
2003年 | 39489篇 |
2002年 | 38300篇 |
2001年 | 60842篇 |
2000年 | 62512篇 |
1999年 | 52274篇 |
1998年 | 14578篇 |
1997年 | 13274篇 |
1996年 | 13114篇 |
1995年 | 12456篇 |
1994年 | 11625篇 |
1993年 | 10920篇 |
1992年 | 41567篇 |
1991年 | 40758篇 |
1990年 | 39444篇 |
1989年 | 37340篇 |
1988年 | 34581篇 |
1987年 | 33693篇 |
1986年 | 32150篇 |
1985年 | 30638篇 |
1984年 | 23034篇 |
1983年 | 19589篇 |
1982年 | 11752篇 |
1979年 | 20804篇 |
1978年 | 14814篇 |
1977年 | 12064篇 |
1976年 | 11876篇 |
1975年 | 12110篇 |
1974年 | 14800篇 |
1973年 | 14472篇 |
1972年 | 13356篇 |
1971年 | 12418篇 |
1970年 | 11485篇 |
1969年 | 10410篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
32.
P E Santos E Piontelli Y R Shea M L Galluzzo S M Holland M E Zelazko S D Rosenzweig 《Medical mycology》2006,44(8):749-753
Infections due to Penicillium species other than P.marneffei are rare. We identified a boy with X-linked chronic granulomatous disease (X-CGD) with a pulmonary nodule and adjacent rib osteomyelitis caused by Penicillium piceum. The only sign of infection was an elevated sedimentation rate. P. piceum was isolated by fine needle aspirate and from excised infected tissues. Surgical removal and one year of voriconazole treatment were very well tolerated and led to complete recovery. Microbiological, microscopic and molecular studies support the fungal diagnosis. P. piceum should be considered as a relevant pathogen in immunocompromised patients. 相似文献
33.
ABSTRACT: Background: Although increases in perinatal mortality risk associated with fetal macrosomia are well documented, the optimal route of delivery for fetuses with suspected macrosomia remains controversial. The objective of this investigation was to assess the risk of neonatal death among macrosomic infants delivered vaginally compared with those delivered by cesarean section. Methods: Data were derived from the U.S. 1995–1999 Linked Live Birth‐Infant Death Cohort files and term (37–44 wk), single live births to United States resident mothers selected. A proportional hazards model was used to analyze the risk of neonatal death associated with cesarean delivery among 3 categories of macrosomic infants (infants weighing 4,000–4,499 g; 4,500–4,999 g; and 5,000+ g). Results: After controlling for maternal characteristics and complications, the adjusted hazard ratio for neonatal death associated with cesarean delivery among the 3 categories of macrosomic infants was 1.40, 1.30, and 0.85. Conclusions: Although cesarean delivery may reduce the risk of death for the heaviest infants (5,000+ g), the relative benefit of this intervention for macrosomic infants weighing 4,000–4,999 g remains debatable. Thus, policies in support of prophylactic cesarean delivery for suspected fetal macrosomia may need to be reevaluated. (BIRTH 33:4 December 2006) 相似文献
34.
B Sedgmen C McMahon D Cairns R J Benzie R L Woodfield 《Ultrasound in obstetrics & gynecology》2006,27(3):245-251
OBJECTIVE: To explore the impact of timing and type of ultrasound, particularly three-dimensional (3D), exposure on maternal-fetal attachment and maternal health behavior during pregnancy. METHODS: Subjects were 68 women aged 18 years or older expecting their first child who presented for a routine ultrasound scan at around either 12 or 18 weeks' gestation in Nepean Hospital, Western Sydney. Women completed questionnaires assessing maternal-fetal attachment and health behavior, and were then allocated arbitrarily to either two-dimensional (2D) or 3D ultrasound examination. Repeat questionnaires were completed 1 week later. RESULTS: Maternal-fetal attachment increased after both 2D and 3D ultrasound exposure, and the effect was moderated by the timing of exposure, with women receiving their first ultrasound examination at around 12 weeks showing the greatest change. Alcohol consumption was the only behavior to show significant change following ultrasound exposure, with a reduction in the reported average number of drinks per week. There was no significant difference in the pattern of change for 2D compared with 3D ultrasound exposure, and no effect of ultrasound exposure on maternal perception of the fetus. CONCLUSIONS: Ultrasound has a positive impact on maternal-fetal attachment, particularly in the first trimester. 3D ultrasound did not offer enhanced benefits. Associations between ultrasound exposure and alcohol consumption warrant further investigation. Larger samples are needed to clarify the moderating effects of gestational age and type of ultrasound exposure. 相似文献
35.
Neurological Sciences - Brain plasticity, intended as the pattern of functional and structural changes in responses to environmental physiological or pathological events, is underlined by several... 相似文献
36.
D Monnier† C Vidal‡ L Martin§ A Danzon¶ F Pelletier† E Puzenat† MP Algros†† D Blanc† R Laurent† PH Humbert† F Aubin† 《Journal of the European Academy of Dermatology and Venereology》2006,20(10):1237-1242
BACKGROUND: Dermatofibrosarcoma protuberans (DFSP) is a rare malignant tumour of the skin, with an estimated incidence of 0.8 to five cases per 1 million people per year. OBJECTIVE: To study epidemiological, immunohistochemical and clinical features, delay in diagnosis, type of treatment and outcome of DFSP from 1982 to 2002. METHODS: Using data from the population-based cancer registry, 66 patients with pathologically proved DFSP were included (fibrosarcomatous DFSP were excluded). Each patient lived in one of the four departments of Franche-Comté (overall population of 1 million people) at the time of diagnosis. The main data sources came from public and private pathology laboratories and medical records. The rules of the International Agency for Research on Cancer were applied. RESULTS: The estimated incidence of DFSP in Franche-Comté was about three new cases per 1 million people per year. Male patients were affected 1.2 times as often as female patients were. The trunk (45%) followed by the proximal extremities (38%) were the most frequent locations. DFSP occurred mainly in young adults between 20 and 39 years of age. Mean age at diagnosis was 43 years, and the mean delay in diagnosis was 10.08 years. Our 66 patients initially underwent a radical local excision. Among them, 27% experienced one or more local recurrences during 9.6 years of follow-up. There was one regional lymph node recurrence without visceral metastases. These recurrences were significantly related to the initial peripheral resection margins. We observed a local recurrence rate of 47% for margins less than 3 cm, vs. only 7% for margins ranging from 3 to 5 cm [P=0.004; OR=0.229 (95%, CI=0.103-0.510)]. The mean time to a first local recurrence was 2.65 years. Nevertheless, there was no death due to the DFSP course at the end of the follow-up, and the final outcome was favourable. CONCLUSION: Our study emphasizes the importance of wide local excision with margins of at least 3 cm in order to prevent local recurrence. However, the recent development of inhibitors of signal transduction by the PDGFB pathway should soon modify the surgical strategy, which is often too mutilating. 相似文献
37.
38.
39.
40.
p53 expression and disease outcome of breast cancer patients undergoing primary chemotherapy with anthracycline-containing regimens 总被引:3,自引:0,他引:3
Primary chemotherapy administered to breast cancer patientsis the best model to identify baseline features able to predictwhich patients may be most likely to benefit or not from a cytotoxicregimen. In the March issue of Annals of Oncology two papersevaluated the predictive role of immunohistochemical p53 expressionon 相似文献