全文获取类型
收费全文 | 3646篇 |
免费 | 500篇 |
国内免费 | 10篇 |
专业分类
耳鼻咽喉 | 208篇 |
儿科学 | 30篇 |
妇产科学 | 119篇 |
基础医学 | 18篇 |
口腔科学 | 63篇 |
临床医学 | 658篇 |
内科学 | 324篇 |
皮肤病学 | 23篇 |
神经病学 | 100篇 |
特种医学 | 72篇 |
外科学 | 1913篇 |
综合类 | 1篇 |
预防医学 | 49篇 |
眼科学 | 413篇 |
药学 | 2篇 |
肿瘤学 | 163篇 |
出版年
2024年 | 16篇 |
2023年 | 65篇 |
2021年 | 14篇 |
2020年 | 87篇 |
2019年 | 14篇 |
2018年 | 114篇 |
2017年 | 120篇 |
2016年 | 141篇 |
2015年 | 136篇 |
2014年 | 261篇 |
2013年 | 275篇 |
2012年 | 101篇 |
2011年 | 121篇 |
2010年 | 208篇 |
2009年 | 303篇 |
2008年 | 106篇 |
2007年 | 79篇 |
2006年 | 145篇 |
2005年 | 72篇 |
2004年 | 43篇 |
2003年 | 37篇 |
2002年 | 34篇 |
2001年 | 89篇 |
2000年 | 41篇 |
1999年 | 50篇 |
1998年 | 89篇 |
1997年 | 120篇 |
1996年 | 110篇 |
1995年 | 108篇 |
1994年 | 103篇 |
1993年 | 85篇 |
1992年 | 96篇 |
1991年 | 70篇 |
1990年 | 46篇 |
1989年 | 61篇 |
1988年 | 70篇 |
1987年 | 35篇 |
1986年 | 45篇 |
1985年 | 28篇 |
1984年 | 36篇 |
1983年 | 23篇 |
1982年 | 34篇 |
1981年 | 23篇 |
1980年 | 20篇 |
1979年 | 18篇 |
1978年 | 15篇 |
1962年 | 16篇 |
1956年 | 28篇 |
1955年 | 22篇 |
1954年 | 15篇 |
排序方式: 共有4156条查询结果,搜索用时 46 毫秒
51.
Mark J Elder MD FRACS FRACO Paul Hiscott PhD FRCS MRCPath John K.G Dart DM FRCS FRCOphth 《Human pathology》1997,28(12):1348-1354
Cicatricial conjunctivitis may be a sequel to systemic disorders (eg, Stevens-Johnson syndrome, cicatricial pemphigoid) or local disorders such as chemical burns. The cicatrisation is often associated with corneal epithelial changes that cause visual loss. These have been attributed to encroachment of the conjunctival epithelium over the cornea. However, the epithelial anomalies are poorly understood. We investigated the corneal epithelial changes in cicatricial conjunctivitis with an immunohistochemical study of intermediate filaments in normal and pathological specimens. Our results show that the normal corneal epithelium is immunoreactive for cytokeratin 3 (CK 3) but not cytokeratin 19 (CK 19), whereas normal conjunctival epithelium is CK 3 negative and CK 19 positive. Conjunctiva artificially transposed over the cornea (after therapeutic conjunctival flap reconstruction) retained the normal pattern of conjunctival cytokeratin expression (CK 3 negative, CK 19 positive). Conversely, the entire corneal epithelium exhibited the normal cytokeratin pattern (CK 3 positive, CK 19 negative) in 82% of Stevens-Johnson, 80% of cicatricial pemphigoid, and 69% of chemical burns specimens. The findings suggest that conjunctival encroachment is not responsible for the changes at the corneal surface in cicatricial conjunctivitis and that the abnormal corneal epithelium is derived from native corneal cells in these diseases. 相似文献
52.
Gerard T. Williams FRCS Christopher J. Underwood B Sc David Charlesworth FRCS 《Annals of vascular surgery》1986,1(2):208-213
We report the early results of a series of 86 femoropopliteal bypass operations in which a 5 mm diameter thin wall polytetrafluoroethylene (Gore-Tex) prosthesis was used. Sixty-five bypasses were implanted in men and 21 in women. Thirty bypasses were done in conjunction with an aortic bifurcation graft and 18 patients had a bilateral procedure. The indication for operation was severe claudication in 74 cases and critical ischaemia in 12 cases. The angiographic run-off was good (three patent vessels) in 22 limbs and poor (one or two patent vessels) in 64 limbs. The cumulative patency rate for the whole group was 62% after 18 months. Angiographic run-off and the indication for operation were both found to influence cumulative patency rate significantly (p=0.035 and p=0.055, respectively). We also compared the results obtained when run-off was poor with equivalent data from our own previously published series in which a standard 6 mm diameter Gore-Tex prosthesis was used. This shows a difference in patency rate, for example 57% against 37% after 18 months, in favour of the smaller bore thin wall graft. 相似文献
53.
Analysis of the morphological aspects of continuous-wave Doppler examination is a reliable means of detecting carotid stenosis involving 50% or more of the diameter of the arterial lumen. This study was undertaken to evaluate the indexes likely to increase the diagnostic accuracy of this noninvasive investigation method. The indexes studied were the variations of the maximal frequency and the systolic peak frequencies, measured proximal to and at the level of stenosis, and the ratio of the systolic peak frequency measured in the internal carotid artery and in the common carotid artery. After obtaining data on an experimental model, the study was conducted in healthy volunteers (n = 24) and in patients with carotid atherosclerotic disease (n = 23). The experimental study confirmed that stenosis greater than 50% leads to a reduction of blood flow and that there is a mathematical relationship between the frequency measured proximal to and at the level of the stenosis and the degree of stenosis. Clinical data showed that there was a significant decrease in the frequency of the systolic peak in elderly "healthy" subjects as compared with younger subjects. However there was no difference between patients with and without stenosis. The index was 0.8 in young subjects, 1.3 in healthy elderly subjects, and greater than 1.3 in subjects who had a stenosis. There was no statistically significant difference between these two last groups. At the threshold value of 2.3, the sensitivity of the FI index was 22% and the specificity was 94% in the detection of carotid artery stenosis. In the assessment of the tight stenosis, sensitivity was 44%. 相似文献
54.
Case reports are presented on three patients treated for morbid obesity by vertical gastroplasty. Prior to surgery the patients
had diabetes which required insulin, up to 200 units per day, or oral hypoglycaemics for its control. Six months after surgery
the diabetes had been resolved in all three patients, and they were no longer dependent on medication. Subjective reports
from the patients suggests that their quality of life improved significantly. 相似文献
55.
Twenty of 26 (77%) consecutive patients undergoing ileogastrostomy, performed by the same surgeon (IGMC) between February
1989 and May 1992, responded to a mailed quality of life survey. Average present weight was reported as 50.9 kg less than
a mean preoperative weight of 139.7 kg. Mean time of follow-up was 24.75 months. When comparing perceptions before and after
surgery, several quality of life improvements were noted in the areas of vocation, relationships, emotional well-being and
physical well-being. Post-surgery, jobs were rated more satisfying, eating habits improved, self-image and self-confidence
increased and body disparagement declined. Satisfaction with sexual relations increased, as did frequency. In general, relations
with partners, co-workers and friends seemed to improve. Exercise also increased significantly. In contrast, foul flatus,
bloating, and bowel movements regularly hampered activities or caused embarassment when in public. Despite these physical
side-effects, we observed that a large majority of persons undergoing ileogastrostomy noted significant improvements in quality
of life. 相似文献
56.
57.
Ramsey-Stewart G 《Obesity surgery》1993,3(4):410-414
The massive weight loss produced by bariatric surgical procedures on the morbidly obese can result in gross redundancy of
abdominal and trunk skin. Standard abdominoplasty procedures may be insufficient to correct this debilitating deformity. A
radical version of the “Fleur-de-Lis” abdominoplasty has been carried out on 45 such patients, with good cosmetic and functional
results and low morbidity. 相似文献
58.
A prospective study of biochemical changes after vertical banded gastroplasty for morbid obesity, in 94 patients (10 males
and 84 females, ages ranging from 18 to 59 years) has been carried out. Liver function tests and electrolyte estimations were
performed preoperatively, during hospitalisation for surgery, at 6 weeks and at 6 months postoperatively, and demonstrated
no significant changes in liver function in these patients 6 months after surgery. The study concludes that there is no increase
in the risk of liver damage or electrolyte disturbance after vertical gastroplasty, but that there may be subtle hepatic changes
present as gall bladder disease developed in 18 patients postoperation (19%). 相似文献
59.
A retrospective study of all ileogastrostomy procedures (n=26) performed in 1993 by one surgeon (IGMC) was carried out to investigate the hypothesis that Helicobacter pylori may be implicated in certain severe cases of postoperation nausea and diarrhea. Ten of 26 persons (38.5%) displayed nausea
and notable diarrhea (greater than or equal to ten bowel movements per day), seven of which warranted upper GI investigation.
One hundred per cent (seven of seven) of these persons were found to possess H. pylori upon C-14 breath test. In four of six cases eradication therapy (1 g amoxicillin b.i.d./20 mg omeprazole b.i.d. for 2 weeks)
corresponded with a resolution of severe nausea and diarrhea (one additional case involved omeprazole use only), suggesting
that H. pylori should be considered as a possible cause of these symptoms post-ileogastrostomy. Additionally, in four of seven cases persons
were re-tested (C-14 breath analysis) at least 1 month post-therapy and in this group three persons were found to be free
of the organism. All three cases of notable diarrhea and nausea resolved with treatment, providing the strongest evidence
for a possible association between infection and these symptoms. 相似文献
60.
Background: this study was designed to characterize some of the biochemical and molecular genetic changes during reversion
of human fat cells. Methods: mature adipocytes were isolated from greater omental fat tissue of eight lean and 14 massively
obese persons by established methodology. Results: at day 7 of adherence to Leighton tubes, there was appreciable depletion
of triacylglycerol, as well as assumption of an elongated contour. Relatedly, there was an increase in the expression of β-actin
mRNA and a significant decrease in the specific activity of cytosolic glycerophosphate dehydrogenase. The decrement in the
specific activity of glycerophosphate dehydrogenase, after 7 days in culture, was significant at p < 0.001. Basic fibroblast growth factor at 10 ngml-1 accelerated significantly (p < 0.03) the decrease in the specific activity of glycerophosphate dehydrogenase in adipose cells from lean subjects. In contrast,
basic fibroblast growth factor had no significant influence on cells from massively obese persons. Conclusion: such resistance
may contribute to the intractability of massive obesity. 相似文献