全文获取类型
收费全文 | 21822篇 |
免费 | 985篇 |
国内免费 | 168篇 |
专业分类
耳鼻咽喉 | 253篇 |
儿科学 | 375篇 |
妇产科学 | 328篇 |
基础医学 | 3236篇 |
口腔科学 | 354篇 |
临床医学 | 1944篇 |
内科学 | 4127篇 |
皮肤病学 | 715篇 |
神经病学 | 2711篇 |
特种医学 | 1196篇 |
外科学 | 2721篇 |
综合类 | 151篇 |
一般理论 | 6篇 |
预防医学 | 931篇 |
眼科学 | 505篇 |
药学 | 1737篇 |
中国医学 | 28篇 |
肿瘤学 | 1657篇 |
出版年
2023年 | 92篇 |
2022年 | 152篇 |
2021年 | 274篇 |
2020年 | 232篇 |
2019年 | 278篇 |
2018年 | 373篇 |
2017年 | 296篇 |
2016年 | 419篇 |
2015年 | 465篇 |
2014年 | 653篇 |
2013年 | 815篇 |
2012年 | 1285篇 |
2011年 | 1364篇 |
2010年 | 776篇 |
2009年 | 786篇 |
2008年 | 1426篇 |
2007年 | 1476篇 |
2006年 | 1548篇 |
2005年 | 1572篇 |
2004年 | 1437篇 |
2003年 | 1472篇 |
2002年 | 1382篇 |
2001年 | 253篇 |
2000年 | 206篇 |
1999年 | 286篇 |
1998年 | 326篇 |
1997年 | 269篇 |
1996年 | 211篇 |
1995年 | 175篇 |
1994年 | 195篇 |
1993年 | 149篇 |
1992年 | 102篇 |
1991年 | 119篇 |
1990年 | 110篇 |
1989年 | 96篇 |
1988年 | 98篇 |
1987年 | 63篇 |
1986年 | 66篇 |
1985年 | 75篇 |
1984年 | 87篇 |
1983年 | 78篇 |
1982年 | 81篇 |
1981年 | 94篇 |
1980年 | 71篇 |
1979年 | 63篇 |
1977年 | 60篇 |
1976年 | 64篇 |
1974年 | 58篇 |
1955年 | 48篇 |
1954年 | 47篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Lia Assumpcao John L. Cameron Christopher L. Wolfgang Barish Edil Michael A. Choti Joseph M. Herman Jean-Francois Geschwind Kelvin Hong Christos Georgiades Richard D. Schulick Timothy M. Pawlik 《Journal of gastrointestinal surgery》2008,12(11):1915-1923
Background
No data on incidence, management, or natural history of chyle leaks following pancreatic resection have been published. We
sought to identify possible risk factors associated with chyle leaks following pancreatic resection, as well as determine
the natural history of this rare complication.
Methods
Between 1993 and 2008, 3,532 patients underwent pancreatic resection at a single institution. Data on demographics, operative
details, primary tumor status, and chyle leak were collected. To identify risk factors associated with chyle leak, a matched
3:1 paired analysis was performed.
Results
Of 3,532 patients undergoing pancreatic resection, 47 (1.3%) developed a chyle leak (n = 34, contained chyle leak versus n = 13, diffuse chylous ascites). Chyle leak was identified at median 5 days following surgery. Median drain triglyceride levels
were 592 ng/dl. After matching on tumor size, disease etiology, and resection type, the number of lymph nodes harvested and
history of concomitant vascular resection predicted higher risk of chyle leak (both P < 0.05). Total parenteral nutrition (TPN) was required in more patients with chylous ascites (92.3%) than those with chyle
leaks (44.1%) (P = 0.003). The median time to resolution was shorter for contained chyle leaks (13 days) versus chylous ascites (36 days)
(P < 0.001). Patients with chylous ascites tended to have shorter overall survival (3-year, 18.8%) versus patients with no chyle
leak (3-year, 46.9%) (P = 0.12). In contrast, patients with a contained chyle leak had a similar survival as patients with no chyle leak (3-year,
53.4% versus 46.9%, respectively) (P = 0.32).
Conclusion
Chyle leak was a rare (1.3%) complication following pancreatic resection that was associated with number of lymph nodes harvested
and concomitant vascular resection. In general, chyle leaks were successfully managed with TPN with no adverse impact on outcome.
Patients with chylous ascites, however, had a more protracted clinical course and tended to have a worse long-term survival.
Presented at the Society for Surgery of the Alimentary Tract, 49th Annual Meeting, San Diego, CA, May 18th, 2008
Support: Dr. Pawlik is supported by Grant Number 1KL2RR025006-01 from the National Center for Research Resources (NCRR), a
component of the National Institutes of Health (NIH), and NIH Roadmap for Medical Research. The contents of this publication
are solely the responsibility of the authors and do not necessarily represent the official view of NCRR or NIH. 相似文献
52.
Dirk Mayer Wolfgang Dreher Dieter Leibfritz Daniel M Spielman 《Magnetic resonance in medicine》2007,57(5):967-971
A numerical simulation tool was developed to calculate the echo amplitudes of J-coupled resonances within a series of radiofrequency (RF) refocused echoes. The signal modulation due to J-coupling in rapid acquisition with relaxation enhancement (RARE) is suppressed only when the inverse of the pulse interval (tau) is large compared to both the chemical shift (CS) difference (Deltadelta) of the coupled spins and the coupling constant. In contrast, the echo amplitudes in ultrafast low-flip-angle RARE (U-FLARE) oscillate around a quasi-steady-state value that is greater than zero (neglecting relaxation and diffusion) even when Deltadelta > 1/tau. The flip-angle distribution over the measured slice caused by the use of Gaussian-shape slice-selective refocusing pulses further reduces the echo oscillations. When the pulse interval falls short of the fast pulse rate regime, spectroscopic U-FLARE provides an improved spatial impulse response in the phase-encoding (PE) direction compared to spectroscopic RARE. 相似文献
53.
54.
John G. Freeman Oddrun Samdal Don A. Klinger Wolfgang Dur Robert Griebler Dorothy Currie Mette Rasmussen 《International journal of public health》2009,54(Z2):251-259
Objectives:
To examine the extent to which school climate and school pressure could predict other aspects of adolescents’ lives, most particularly their emotional health and bullying. Furthermore, the study sought to investigate if these relationships were consistent across countries. 相似文献55.
56.
Nicole Rotter Hubert Wagner Sabine Fuchshuber Wolfgang J. Issing 《European archives of oto-rhino-laryngology》2003,260(5):254-257
Microcystic adnexal carcinoma is a rare cutaneous neoplasm characterized by slow but locally aggressive growth, which normally does not lead to systemic metastasis. Frequent local recurrences are reported, which are most likely due to insufficient operative technique. We present the fourth case of cervical ipsilateral metastatic microcystic adnexal carcinoma in an otherwise healthy woman. The patient presented with a previously diagnosed but not completely resected microcystic adnexal carcinoma in the area of the right posterior scalp and two palpable ipsilateral lymph nodes. The tumor was resected using intraoperative snap frozen histological evaluation of the resection borders. In the same procedure two lymph nodes were resected from the right neck. The lymph nodes were histologically assessed and showed infiltration by small strains of tumor cells. After exclusion of a second primary tumor, e.g., mammary carcinoma, as the cause for cervical lymph node metastases, we performed a modified radical neck dissection with resection of the sternocleidomastoid muscle and the accessory nerve, which was histologically proven to be perineurally infiltrated by tumor cells. In this second procedure the histological evaluation of the specimen showed no sign of remaining tumor infiltration. After exclusion of distant metastasis the patient was irradiated with 60 Gy. The patient is well 1 year after the initial treatment without signs of recurrence. 相似文献
57.
58.
Wolfgang Skrandies 《Documenta ophthalmologica. Advances in ophthalmology》2009,119(3):209-216
Dynamic random-dot stereograms (dRDS) elicit brain activity generated exclusively by cortical neurons sensitive to binocular
horizontal disparity. We studied 20 adults with stereovision deficiency but otherwise normal vision. Psychophysical thresholds
were determined with static RDS and with the three-rod experiment. VEP was recorded from seven occipital channels. Stimuli
were presented on a monitor by dRDS as stereoscopic checkerboard patterns that moved in depth with 8 depth reversals per second.
Horizontal disparity ranged from 7 to 24.5 min of arc. Stimuli were displayed at the center, or in the left or right half
field. We determined electrophysiological thresholds as well as the disparity where largest responses occurred. Subjective
and electrophysiological thresholds showed a significant positive correlation. In addition, the right visual field was more
sensitive to dRDS stimuli than other locations. Squint angle was related to the disparity thresholds. Our data illustrate
correlations between clinical symptoms, perceptual deficiency, and VEP parameters. 相似文献
59.
60.
Wolfgang H Oertel Tobias W?chter Niall P Quinn Gudrun Ulm Dirk Brandst?dter 《Movement disorders》2003,18(4):430-432
According to the consensus statement on the diagnosis of multiple system atrophy (MSA), erectile dysfunction is required for male patients to fulfil the urinary incontinence criterion. However, there is no equivalent item for female patients. We questioned 19 female patients with MSA of the parkinsonian type (MSA-P), 28 female patients with Parkinson's disease (PD), and 27 healthy controls on their genital sensitivity. A total of 47% of the MSA patients but only 4% of the PD patients and 4% of the control group admitted to reduced genital sensitivity, a highly significant difference (P < 0.001). Moreover, the appearance of reduced genital sensitivity in female MSA patients showed a close temporal relation to the onset of the disease. If these preliminary results can be confirmed and further specified in a larger sample, a historical item of reduced genital sensitivity in female patients might become a diagnostic feature for MSA, comparable to erectile dysfunction in male patients. 相似文献