全文获取类型
收费全文 | 16266篇 |
免费 | 539篇 |
国内免费 | 186篇 |
专业分类
耳鼻咽喉 | 158篇 |
儿科学 | 581篇 |
妇产科学 | 289篇 |
基础医学 | 1234篇 |
口腔科学 | 425篇 |
临床医学 | 1923篇 |
内科学 | 3618篇 |
皮肤病学 | 336篇 |
神经病学 | 827篇 |
特种医学 | 499篇 |
外科学 | 2947篇 |
综合类 | 192篇 |
一般理论 | 5篇 |
预防医学 | 890篇 |
眼科学 | 819篇 |
药学 | 1002篇 |
2篇 | |
中国医学 | 51篇 |
肿瘤学 | 1193篇 |
出版年
2023年 | 176篇 |
2022年 | 173篇 |
2021年 | 327篇 |
2020年 | 240篇 |
2019年 | 241篇 |
2018年 | 379篇 |
2017年 | 330篇 |
2016年 | 374篇 |
2015年 | 388篇 |
2014年 | 547篇 |
2013年 | 704篇 |
2012年 | 701篇 |
2011年 | 760篇 |
2010年 | 543篇 |
2009年 | 658篇 |
2008年 | 571篇 |
2007年 | 539篇 |
2006年 | 590篇 |
2005年 | 506篇 |
2004年 | 441篇 |
2003年 | 429篇 |
2002年 | 391篇 |
2001年 | 394篇 |
2000年 | 373篇 |
1999年 | 351篇 |
1998年 | 279篇 |
1997年 | 267篇 |
1996年 | 367篇 |
1995年 | 321篇 |
1994年 | 236篇 |
1993年 | 162篇 |
1992年 | 279篇 |
1991年 | 298篇 |
1990年 | 224篇 |
1989年 | 268篇 |
1988年 | 239篇 |
1987年 | 243篇 |
1986年 | 237篇 |
1985年 | 194篇 |
1984年 | 201篇 |
1983年 | 155篇 |
1982年 | 118篇 |
1981年 | 99篇 |
1980年 | 128篇 |
1979年 | 105篇 |
1978年 | 105篇 |
1977年 | 98篇 |
1976年 | 102篇 |
1975年 | 102篇 |
1974年 | 110篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
A TEN-YEAR HOSPITAL SURVEY OF EYELID CANCER 总被引:1,自引:0,他引:1
IAN C. FRANCIS FRACO FRACS PETER. S. BENECKE MB BS MEDDUMA. B. KAPPAGODA FRACO FRACS 《Clinical & experimental ophthalmology》1984,12(2):121-127
Two hundred and four cases of malignant eyelid tumours, managed at the Concord Hospital, were reviewed. These cases spanned a ten-year period between 1973 and 1982 and all were treated surgically. The nature of each tumour was confirmed by histopathological examination. Included in this review were the site of the tumour, the tumour pathology, the surgical management, the type of surgeon involved, the ocular complications, the management of recurrences and any mortality. The importance of preventing recurrences by adequate initial surgery with frozen section control is emphasized. 相似文献
52.
Andrew A. Chang MB BS Alan Bank FRACO FRACS Ian C. Francis FRACO FRACS Medduma B. Kappagoda FRACO FRACS FRCS 《Clinical & experimental ophthalmology》1995,23(4):315-318
Exophthalmometry, the quantitative assessment of the position of the globe in the orbit, is a clinically useful measurement. The purpose of this study was to examine the performance of a simple exophthal-mometer that would lend itself to accurate and convenient use in clinical practice. In this study, two observers independently performed exophthalmometry on 100 eyes using the Hertel and Luedde instruments. The results were compared between instruments and between observers. There was no statistically or clinically significant difference between measurements taken with the Luedde as compared with the Hertel instrument. The Luedde exophthal-mometer has a number of advantages over the Hertel exophthalmometer, and represents a simple, inexpensive and equally reliable means of evaluating clinically the anteroposterior position of the eye in the orbit. 相似文献
53.
The clinical features of the maternal syndrome of pre-eclampsia can be explained by generalised maternal endothelial cell dysfunction, which is a part of a more global maternal systemic inflammatory response. There is growing evidence that these effects are associated with the shedding of cellular debris, including syncytiotrophoblast microparticles (STBM), cell-free DNA and mRNA, from the surface of the placenta (syncytiotrophoblast) into the maternal circulation. The increased shedding of this debris seen in pre-eclampsia is believed to be caused by placental ischaemia, reperfusion and oxidative stress. This study was carried out to determine whether uterine contractions during labour and subsequent placental separation lead to an acute increase in the release of placental debris into the maternal circulation. To assess the effects of labour, samples were taken from 10 normal pregnant (NP) and 10 pre-eclamptic (PE) women at varied time points. Similarly to assess the effects of placental delivery, plasma samples were taken from 10 NP and 10 PE women undergoing elective caesarean section. There was a significant increase in the shedding of STBM in pre-eclampsia which was not seen in normal pregnancy and there was a small rise in STBM levels at placental separation in both normal pregnant and pre-eclamptic women undergoing caesarean section, but the differences were not significant. However, levels of placental cell-free corticotrophin releasing hormone mRNA were significantly increased in labour in both normal pregnancy and pre-eclampsia and were still high 24 h after delivery in the pre-eclamptic women. There was no significant increase in fetal or total DNA in labour, but the overall levels of total DNA (maternal and fetal) was increased in labour in pre-eclampsia compared to normal labour. The enhanced shedding of STBM and CRH mRNA in pre-eclampsia labour may have a role in cases of postpartum worsening of pre-eclampsia. 相似文献
54.
On September 21 and 22, 2006, the National Institute of Child Health and Human Development of the National Institutes of Health sponsored a 2-day workshop titled "Preeclampsia--A Pressing Problem." The purpose of the workshop was to bring together leaders in the field to present and discuss their diverse research areas, which ranged from basic science to clinical trials and management, and to identify scientific gaps. This article is a summary of the proceedings of that workshop. Although much progress is being made in understanding the underpinnings of preeclampsia, a number of research gaps are identified that, if filled, would hasten progress in the field. It is the overall consensus that preeclampsia is a multifactorial disease whose pathogenesis is not solely vascular, genetic, immunologic, or environmental but a complex combination of factors. In addition, a number of specific scientific gaps are identified including insufficient multidisciplinary and collaborative research, clinical trials and studies of patient management, and a lack of in-depth mechanistic research. The research community needs to focus on these gaps to better understand the disease, with the ultimate goal of preventing the disorder. 相似文献
55.
Laparoscopic versus open splenectomy in the pediatric population: a contemporary single-center experience 总被引:5,自引:0,他引:5
Reddy VS Phan HH O'Neill JA Neblett WW Pietsch JB Morgan WM Cywes R 《The American surgeon》2001,67(9):859-63; discussion 863-4
The purpose of this study was to compare a recent contemporaneous experience between laparoscopic (LS) and open (OS) splenectomy in children. All splenectomy cases between 1994 and 1999 at our institution were reviewed. The study included open and laparoscopic cases performed according to surgeon preference. Emergency splenectomies for trauma were excluded. The patient record was reviewed for the diagnosis, indications, postoperative length of stay, operative technique, postoperative complications, blood loss/blood transfusion, total amount of parenteral narcotics, and time to resumption of oral intake. Chi-square and t tests were used to compare measured differences for statistical significance. Between May 1994 and December 1999, 52 splenectomies were performed at Vanderbilt Children's Hospital. Of these, 45 were elective operations with 29 open and 16 laparoscopic procedures. During four OS and five LS operations a concomitant cholecystectomy was performed. The median patient age was 9.2 years (range 0.5 to 17.3). There was no statistical difference between the two groups in terms of age, weight, American Society of Anesthesiologists class, or estimated blood loss. There were no immediate postoperative complications in either group. There were no conversions from LS to OS. The mean duration of surgery was 264 minutes (LS) versus 169 minutes (OS) (P < 0.05). The average time to first oral intake was shorter in patients undergoing LS (1.1 vs 1.6 days, P < 0.05) and the mean postoperative length of stay was also shorter in the LS group (1.3 vs 3.1 days, P < 0.05). The use of postoperative intravenous narcotics (in morphine-equivalent doses) was significantly less in LS patients than in OS patients (7.5 mg or 0.15 mg/kg vs 46.9 mg or 1.5 mg/kg, P < 0.001), as was the need for PCA pump analgesia (90% in the OS group vs 25% in LS group, P < 0.01). Overall the average hospital charge (anesthesia fee, narcotics charge, and hospital room charge) was $5400 (range $4240-6250) in the OS group and $4950 (range $4450-6240) in the LS group (P < 0.05). Among the nine patients undergoing splenectomy with cholecystectomy, findings between the OS and LS groups were similar except for one late complication consisting of a diaphragmatic hernia in an LS patient. Both LS and OS with or without a concomitant procedure can be accomplished safely in children. LS appears to result in longer operative times but shorter lengths of stay, earlier first oral intake, and significantly fewer requirements for intravenous narcotics; all of these contribute to a reduction in hospital charges compared with the open operation. 相似文献
56.
57.
58.
59.
60.
Yingying Liu Jihyeung Ju Hang Xiao Barbara Simi Xingpei Hao Bandaru S. Reddy 《Nutrition and cancer》2013,65(5):660-665
Human intervention studies have suggested an exciting synergistic action between calcium supplementation and aspirin intake in reducing the risk of colorectal cancer. The aim of this study was to determine whether such a synergy can be demonstrated on azoxymethane (AOM)-induced colon aberrant crypt foci (ACF) formation in mice and rats. Female CF-1 mice and male F344 rats were injected subcutaneously with AOM and then received diet treatments for 8 wk. The basal control diet contained high fat (20% mixed lipids by weight) and low calcium (1.4 mg/g diet) to mimic the average Western diet. The treatment diets contained enriched calcium (5.2 mg calcium/g diet), aspirin (0.2 mg aspirin/g diet), or calcium plus aspirin (5.2 mg calcium plus 0.2 mg aspirin/g diet). Treatment with calcium, aspirin, or their combination significantly decreased the number of total ACF and aberrant crypt per mouse (by 43–59%) or rat (by 23–38%), but statistically significant differences among the 3 groups were not observed. A hint of additivity between calcium and aspirin was observed in mice but not in rats. These results indicate that the combination of calcium and aspirin did not produce a synergistic effect on the ACF formation in AOM-treated mice and rats. 相似文献