全文获取类型
收费全文 | 30039篇 |
免费 | 2461篇 |
国内免费 | 105篇 |
专业分类
耳鼻咽喉 | 258篇 |
儿科学 | 691篇 |
妇产科学 | 518篇 |
基础医学 | 4192篇 |
口腔科学 | 379篇 |
临床医学 | 3268篇 |
内科学 | 6516篇 |
皮肤病学 | 356篇 |
神经病学 | 2749篇 |
特种医学 | 974篇 |
外科学 | 4888篇 |
综合类 | 381篇 |
现状与发展 | 1篇 |
一般理论 | 27篇 |
预防医学 | 2346篇 |
眼科学 | 460篇 |
药学 | 2189篇 |
中国医学 | 47篇 |
肿瘤学 | 2365篇 |
出版年
2023年 | 268篇 |
2022年 | 475篇 |
2021年 | 1046篇 |
2020年 | 548篇 |
2019年 | 869篇 |
2018年 | 993篇 |
2017年 | 703篇 |
2016年 | 727篇 |
2015年 | 835篇 |
2014年 | 1142篇 |
2013年 | 1451篇 |
2012年 | 2288篇 |
2011年 | 2269篇 |
2010年 | 1232篇 |
2009年 | 1055篇 |
2008年 | 1766篇 |
2007年 | 1787篇 |
2006年 | 1639篇 |
2005年 | 1581篇 |
2004年 | 1504篇 |
2003年 | 1405篇 |
2002年 | 1368篇 |
2001年 | 353篇 |
2000年 | 305篇 |
1999年 | 331篇 |
1998年 | 305篇 |
1997年 | 264篇 |
1996年 | 230篇 |
1995年 | 204篇 |
1994年 | 205篇 |
1993年 | 176篇 |
1992年 | 248篇 |
1991年 | 195篇 |
1990年 | 204篇 |
1989年 | 193篇 |
1988年 | 183篇 |
1987年 | 179篇 |
1986年 | 144篇 |
1985年 | 140篇 |
1984年 | 159篇 |
1983年 | 120篇 |
1982年 | 121篇 |
1981年 | 110篇 |
1980年 | 117篇 |
1979年 | 96篇 |
1978年 | 106篇 |
1977年 | 85篇 |
1975年 | 78篇 |
1974年 | 74篇 |
1971年 | 70篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
Rohan Ameratunga Nicholas Randall Stuart Dalziel Brian J. Anderson 《Paediatric anaesthesia》2013,23(8):757-759
Aspirin‐exacerbated respiratory disease (AERD) has been recognized in adults with chronic asthma. Samter's triad is a subset of AERD where adult patients develop nasal polyps, asthma, and sensitivity to aspirin. This condition is thought not to occur before the third decade of life. We report a 13‐year‐old boy with nasal polyps who suffered a life‐threatening exacerbation of asthma during a graded aspirin challenge. Resuscitation required positive pressure ventilation and inotropic support. Our observations confirm that classical Samter's triad can occur in children. We suggest that graded aspirin challenges in children are undertaken in a facility with equipment and staff trained for resuscitation. Consideration should be given to this rare complication when prescribing nonsteroidal anti‐inflammatory drugs in the perioperative period. Suspicion of this condition merits referral to an immunologist for desensitization to aspirin. 相似文献
992.
993.
994.
995.
C. J. Walter L. T. O. Bell S. R. Parsons C. Jackson N. R. Borley J. M. D. Wheeler 《Colorectal disease》2013,15(1):52-56
Aim The study aimed to assess the prevalence and significance of anaemia during long‐course neoadjuvant radiotherapy for rectal cancer at our centre. Method Hospital coding and a prospective oncology database were used to identify all patients undergoing long‐course neoadjuvant radiotherapy for rectal cancer at our centre between 2004 and 2009. A retrospective review of computerized records was used to extract individual patient data. Anaemia was defined as a haemoglobin level of < 11.5 g/dl for women and of < 13 g/dl for men. Downstaging was assessed by comparing radiological stage (rTNM) with histological stage (ypTNM). Tumour regression after radiotherapy was assessed using the Rectal Cancer Regression Group (RCRG) scores of 1–3. The results were analysed using Gnu PSPP statistical software. Results There were 70 patients (51 men) of median age 66 (interquartile range 60–72.75) years. Of these, 24 were anaemic. Two (3%) had no haemoglobin level recorded and were excluded. Forty‐two per cent of anaemic patients demonstrated mural (T) downstaging compared with 68% of nonanaemic patients (P = 0.03). There was no difference in nodal downstaging between the groups. The RCRG scores showed more tumour regression in nonanaemic patients than in anaemic patients, as follows: RCRG 1, 59%vs 30%; RCRG 2, 11%vs 17%; and RCRG 3, 38%vs 46% (P < 0.001). Conclusion The prevalence of anaemia in patients undergoing long‐course neoadjuvant radiotherapy was 35%. Anaemia during long‐course neoadjuvant radiotherapy was associated with significant reductions in tumour downstaging and regression. 相似文献
996.
997.
Hidekazu Sugawara Todd A. Linsenmeyer Heather Beam J. Russell Parsons 《The journal of spinal cord medicine》2013,36(4):302-308
AbstractPathologic fractures may occur with minimal trauma after spinal cord injury (SCI) because of osteoporosis. Rats were evaluated to determine whether they could be used as an SCI animal model. Male Sprague-Dawley rats underwent spinal cord transection at the ninth thoracic vertebrae. Control rats underwent a sham procedure. Mechanical testing of the humeral shaft, femoral shaft, tibial shaft, femoral neck, distal femur, and proximal tibia was performed separately at 0, 8, and 24 weeks after surgery. At 24 weeks, significant differences between SCI and control rats were found in maximum torque needed to produce failure in the femoral shaft (63 percent of control, p < 0.05) and tibial shaft (63 percent, p < 0.01), and in compressive load to produce failure in cross-sectional specimens of the distal femur (51 percent, p < 0.05) and proximal tibia (50 percent, p < 0.01 ). No differences were found in the maximum torque needed to produce failure of the humeral shaft (106 percent, p = 0.77) between SCI and control rats. Reductions in relative bone strength in SCI rats at 24 weeks were similar in magnitude to bone mineral density changes reported in humans with chronic paraplegia. Thus, Sprague-Dawley rats appear to be good animal models in which to evaluate changes in bone strength following SCI. U Spinal Cord Med 1998; 21:302-308) 相似文献
998.
Arthroplasty for ochronotic arthritisNo failure of 11 replacements in 3 patients followed 6–12 years
Jonathan Spencer C L Maxime Gibbons Robert Sharp Andrew Carr Nicholas Athanasou 《Acta orthopaedica》2013,84(3):355-358
Background?Alkaptonuria is a rare single-gene disorder characterized by black pigmentation of cartilage and other connective tissues. Premature degenerative arthritis affects the large joints in many of these of patients. Medical treatment is limited to a protein-restricted diet (phenylalanine and tyrosine) with surgery reserved for end-stage joint disease. As in other metabolic bone diseases, there are concerns about the quality and strength of affected bones and therefore the suitability and longevity of replacement arthroplasty. The histopathology and outcome of joint replacement for alkaptonuric arthritis is unknown and limited to sporadic case reports.Patients and results?We describe 11 joint replacements in 3 patients with alkaptonuric polyarthropathy, including shoulder and elbow replacements not previously reported. No prosthetic failures occurred in up to 12 years of follow-up.Interpretation?Total joint replacement is an acceptable treatment for degenerative joint disease in alkaptonuric patients, with implant survival comparable to that found in patients with osteoarthritis. 相似文献
999.
Ali Ashraf A. Noelle Larson Gabriela Ferski Cary H. Mielke Nicholas M. Wetjen Kenneth J. Guidera 《Journal of children's orthopaedics》2013,7(3):183-194
Purpose
Children with multiple hereditary exostoses (MHE) have numerous osteochondromas, with the most prominent lesions typically over the appendicular skeleton. A recent report noted a high rate of intracanal lesions in this patient population and recommended preventative spinal screening with magnetic resonance imaging (MRI) or computed tomography (CT). We sought to evaluate the prevalence of spinal stenosis from intracanal osteochondromas at our pediatric orthopedic center in order to evaluate if routine screening is warranted.Methods
All pediatric patients treated for MHE were retrospectively identified. Records were reviewed to determine demographics, previous orthopedic surgery, and indication and results of axial spine imaging (CT or MRI). Imaging studies were reviewed to evaluate the presence of intracanal and compressive spinal lesions.Results
Between 1990 and 2011, axial imaging was performed in nine patients with MHE due to concerns of pain, weakness, and/or dizziness. These patients had moderate disease involvement, with a mean of 4.9 previous orthopedic surgeries to address skeletal osteochondromas. Two patients with MHE had cervical spinal stenosis secondary to intracanal osteochondromas. Both children successfully underwent spinal decompression. Thus, of our MHE population undergoing axial imaging, 22 % were noted to have intracanal lesions.Conclusions
Our experience reveals a >20 % rate of compressive intracanal osteochondromas in MHE patients undergoing spinal imaging. These two patients represent 5 % of the MHE patients treated at our center. These lesions may be slow growing, and significant consequences can occur if not identified promptly. Thus, we confer that routine axial screening of the spinal canal may be warranted in these children. 相似文献1000.