全文获取类型
收费全文 | 12867篇 |
免费 | 748篇 |
国内免费 | 26篇 |
专业分类
耳鼻咽喉 | 97篇 |
儿科学 | 383篇 |
妇产科学 | 189篇 |
基础医学 | 1601篇 |
口腔科学 | 404篇 |
临床医学 | 1370篇 |
内科学 | 2538篇 |
皮肤病学 | 159篇 |
神经病学 | 1247篇 |
特种医学 | 354篇 |
外科学 | 2029篇 |
综合类 | 102篇 |
一般理论 | 9篇 |
预防医学 | 859篇 |
眼科学 | 306篇 |
药学 | 1026篇 |
中国医学 | 19篇 |
肿瘤学 | 949篇 |
出版年
2023年 | 98篇 |
2022年 | 112篇 |
2021年 | 240篇 |
2020年 | 220篇 |
2019年 | 312篇 |
2018年 | 298篇 |
2017年 | 281篇 |
2016年 | 312篇 |
2015年 | 302篇 |
2014年 | 431篇 |
2013年 | 673篇 |
2012年 | 888篇 |
2011年 | 891篇 |
2010年 | 475篇 |
2009年 | 471篇 |
2008年 | 801篇 |
2007年 | 842篇 |
2006年 | 788篇 |
2005年 | 718篇 |
2004年 | 699篇 |
2003年 | 663篇 |
2002年 | 606篇 |
2001年 | 136篇 |
2000年 | 106篇 |
1999年 | 146篇 |
1998年 | 172篇 |
1997年 | 157篇 |
1996年 | 123篇 |
1995年 | 105篇 |
1994年 | 112篇 |
1993年 | 82篇 |
1992年 | 81篇 |
1991年 | 93篇 |
1990年 | 85篇 |
1989年 | 85篇 |
1988年 | 68篇 |
1987年 | 69篇 |
1986年 | 76篇 |
1985年 | 88篇 |
1984年 | 71篇 |
1983年 | 62篇 |
1982年 | 90篇 |
1981年 | 50篇 |
1980年 | 50篇 |
1979年 | 51篇 |
1978年 | 38篇 |
1977年 | 33篇 |
1976年 | 35篇 |
1975年 | 24篇 |
1974年 | 26篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
Thorir Svavar Sigmundsson Tomas Öhman Magnus Hallbäck Eider Redondo Fernando Suarez Sipmann Mats Wallin Anders Oldner Caroline Hällsjö Sander Håkan Björne 《Journal of clinical monitoring and computing》2018,32(2):311-319
The capnodynamic method is a minimally invasive method continuously calculating effective pulmonary blood flow (COEPBF), equivalent to cardiac output when intra pulmonary shunt flow is low. The capnodynamic equation joined with a ventilator pattern containing cyclic reoccurring expiratory holds, provides breath to breath hemodynamic monitoring in the anesthetized patient. Its performance however, might be affected by changes in the mixed venous content of carbon dioxide (CvCO2). The aim of the current study was to evaluate COEPBF during rapid measurable changes in mixed venous carbon dioxide partial pressure (PvCO2) following ischemia–reperfusion and during sustained hypercapnia in a porcine model. Sixteen pigs were submitted to either ischemia–reperfusion (n?=?8) after the release of an aortic balloon inflated during 30 min or to prolonged hypercapnia (n?=?8) induced by adding an instrumental dead space. Reference cardiac output (CO) was measured by an ultrasonic flow probe placed around the pulmonary artery trunk (COTS). Hemodynamic measurements were obtained at baseline, end of ischemia and during the first 5 min of reperfusion as well as during prolonged hypercapnia at high and low CO states. Ischemia–reperfusion resulted in large changes in PvCO2, hemodynamics and lactate. Bias (limits of agreement) was 0.7 (?0.4 to 1.8) L/min with a mean error of 28% at baseline. COEPBF was impaired during reperfusion but agreement was restored within 5 min. During prolonged hypercapnia, agreement remained good during changes in CO. The mean polar angle was ?4.19° (?8.8° to 0.42°). Capnodynamic COEPBF is affected but recovers rapidly after transient large changes in PvCO2 and preserves good agreement and trending ability during states of prolonged hypercapnia at different levels of CO. 相似文献
993.
994.
995.
996.
Background
Most composite indices of disease activity and response criteria in RA have been validated and compared in clinical trials rather than routine care. We therefore wanted to compare the performance of the DAS28, SDAI and CDAI activity indices, their activity states, their response criteria, and also compare with the ACR response criteria in an observational clinical setting. 相似文献997.
Emelie Styring Josefin Fernebro Per-Ebbe J?nsson Anna Ehinger Jacob Engellau Pehr Rissler Anders Rydholm Mef Nilbert Fredrik Vult von Steyern 《Breast cancer research and treatment》2010,122(3):883-887
Angiosarcoma is a rare complication of breast cancer treatment. In order to define predictors, clinical presentation, and
outcome, we characterized a population-based 50-year cohort of angiosarcomas after breast cancer. Clinical data were collected
from all females with previous breast cancer who developed angiosarcomas/lymphangiosarcomas on the thoracic wall/upper extremity
between 1958 and 2008 in the Southern Swedish health care region. In total, 31 angiosarcomas developed at a median age of
71 years. The patients formed two distinct groups; 14 females treated for breast cancer with radical mastectomy and radiotherapy
1949–1988 developed angiosarcomas in edematous arms (Stewart–Treves syndrome) after median 11 years, and 17 females treated
by segmental resection, anti-hormonal treatment and radiotherapy 1980–2005 developed angiosarcomas in the irradiated field
on the thoracic wall after median 7.3 years. The clinical presentations were heterogeneous and included hematoma-like lesions,
multiple bluish-reddish nodules, and asymptomatic lumps. The overall 5-year survival was 16%. In this population-based cohort,
the early angiosarcomas developed in edematous arms after radical mastectomies, whereas more recent cases occurred after a
shorter time period in the irradiated fields following breast conserving surgery. We conclude that the clinical presentation
of angiosarcomas has changed, parallel with altered treatment principles for breast cancer. 相似文献
998.
Anders Troelsen Inger Mechlenburg John Gelineck Lars Bolvig Steffen Jacobsen Kjeld S?balle 《Acta orthopaedica》2009,80(3):314-318
Background and purpose An acetabular labral tear is a diagnostic challenge. Various clinical tests have been described, but little is known about their diagnostic sensitivity and specificity. We investigated the diagnostic validity of clinical tests and ultra-sound as compared with MR arthrography.Patients and methods We examined 18 patients (18 hips, 2 men, median age 43 (32–56) years) with impingement test, FABER test, resisted straight leg raise test, ultrasound, and MR arthrography. They had had previous periacetabular osteotomies due to symptomatic, acetabular dysplasia. All hips showed no or only slight signs of osteoarthritis (Tönnis grade 0–1).Results MR arthrography identified labral tears in 17 of the 18 hips. Ultrasound had a sensitivity of 94%, a positive predictive value of 94%, and was false negative in only 1 case compared to MR arthrography. The impingement test had the best diagnostic ability of the clinical tests, with a sensitivity of 59% and a specificity of 100%. The positive predictive value was 100% while the negative predictive value was 13%.Interpretation The impingement test is helpful in identifying acetabular labral tears. If this test is negative and if a labral tear is still suspected, ultrasound can reliably diagnose most tears of the acetabular labrum. MR arthrography is indicated in cases where ultrasound is negative, but the patient suffers continued, specific symptoms. 相似文献
999.
Johannes Beckmann Markus Tingart Juergen Goetz Sven Anders Joachim Grifka Franz Kock 《Central European Journal of Medicine》2008,3(1):89-95
Core decompression by exact drilling into ischemic lesions of the femoral condyle stays a challenging procedure, particularly in obese patients. The precision of fluoroscopically-based drilling compared to conventional drilling was evaluated in an in-vitro model for obesity. 40 sawbones were prepared mimicking osteonecrosis in obese patients. 20 sawbones were drilled by guidance of an intraoperative navigation system VectorVision® (BrainLAB, Munich, Germany); the other 20 sawbones were conventionally drilled by fluoroscopic control only. Regarding the distance to the desired mid-point of the lesion, a statistically significant difference with 0.55 mm in the navigated group and 1.19 mm in the control group could be stated (p<0.001). Significant differences were further found for the number of drilling corrections (p<0.001) and radiation time needed (p<0.001). Even in difficult circumstances as in obese patients, the drilling guided by the VectorVision®-navigation system shows high precision with simultaneous enormous reduction of radiation time. 相似文献
1000.
Monica Bergqvist Johanna Ulfvarson Eva Andersén Karlsson 《European journal of clinical pharmacology》2009,65(11):1089-1096