全文获取类型
收费全文 | 12785篇 |
免费 | 699篇 |
国内免费 | 54篇 |
专业分类
耳鼻咽喉 | 86篇 |
儿科学 | 496篇 |
妇产科学 | 290篇 |
基础医学 | 1905篇 |
口腔科学 | 212篇 |
临床医学 | 1393篇 |
内科学 | 2670篇 |
皮肤病学 | 261篇 |
神经病学 | 1367篇 |
特种医学 | 347篇 |
外科学 | 1211篇 |
综合类 | 78篇 |
一般理论 | 9篇 |
预防医学 | 1047篇 |
眼科学 | 218篇 |
药学 | 899篇 |
中国医学 | 50篇 |
肿瘤学 | 999篇 |
出版年
2023年 | 95篇 |
2022年 | 211篇 |
2021年 | 361篇 |
2020年 | 219篇 |
2019年 | 316篇 |
2018年 | 376篇 |
2017年 | 257篇 |
2016年 | 291篇 |
2015年 | 379篇 |
2014年 | 493篇 |
2013年 | 695篇 |
2012年 | 1016篇 |
2011年 | 1063篇 |
2010年 | 558篇 |
2009年 | 502篇 |
2008年 | 817篇 |
2007年 | 871篇 |
2006年 | 818篇 |
2005年 | 773篇 |
2004年 | 703篇 |
2003年 | 683篇 |
2002年 | 621篇 |
2001年 | 84篇 |
2000年 | 68篇 |
1999年 | 100篇 |
1998年 | 122篇 |
1997年 | 104篇 |
1996年 | 74篇 |
1995年 | 75篇 |
1994年 | 61篇 |
1993年 | 49篇 |
1992年 | 50篇 |
1991年 | 42篇 |
1990年 | 35篇 |
1989年 | 31篇 |
1988年 | 42篇 |
1987年 | 30篇 |
1986年 | 34篇 |
1985年 | 42篇 |
1984年 | 41篇 |
1983年 | 44篇 |
1982年 | 41篇 |
1981年 | 44篇 |
1980年 | 34篇 |
1979年 | 23篇 |
1978年 | 25篇 |
1977年 | 15篇 |
1976年 | 15篇 |
1975年 | 15篇 |
1974年 | 13篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
32.
Evaluation of a Commercial PCR Kit for Diagnosis of Cytomegalovirus Infection of the Central Nervous System 总被引:3,自引:2,他引:1 下载免费PDF全文
Adriana Weinberg Debbie Spiers Guan-Yung Cai Christopher M. Long Rita Sun Vince Tevere 《Journal of clinical microbiology》1998,36(11):3382-3384
We evaluated the AMPLICOR cytomegalovirus (CMV) PCR kit for the diagnosis of neurologic CMV infections on 43 positive and 112 negative archived cerebrospinal fluid specimens originally tested by an in-house PCR method. The AMPLICOR kit showed sensitivity and specificity of 95 and 100%, respectively, versus the home-grown assay, indicating its utility in this clinical setting. 相似文献
33.
Rita M. Kesteven 《Canadian Medical Association journal》1992,146(11):1899-1900
34.
Eneida F. Vencio Rita C. Alencar Eduardo Zancope 《Journal of oral pathology & medicine》2007,36(2):120-122
A 13-year-old boy had complained of an asymptomatic swelling in the anterior maxilla for approximately 4 years. The patient reported no local trauma. The intra-oral examination revealed an exophytic lesion in the incisive papilla between the maxillary central and lateral incisor teeth. The radiographies detected no significant findings. Histopathologically, the lesion showed a dense fibrous tissue above the overlying mucosa. Bone ossification lay beneath a partially hypertrophic cartilage showing occasionally pleomorphic chondrocytes. Because of its microscopic aspects, heterotopic ossification may be mistaken for chondrosarcoma or other conditions involving periosteum, such as parosteal osteosarcoma. A case of heterotopic ossification in the anterior maxilla is presented, and clinicopathologic similarities with other osteochondromatous lesions are discussed. 相似文献
35.
Shahid Hussain Darren E Dreyfus Richard J Marcus Robert W W Biederman Rita L McGill 《Nephrology, dialysis, transplantation》2003,18(11):2364-2368
BACKGROUND: Spironolactone is useful in heart failure, but is not given to dialysis patients for fear of hyperkalaemia. This study evaluated the safety of spironolactone administration in haemodialysis patients. METHODS: Fifteen haemodialysis outpatients with mean serum potassium <5.6 mEq/l over the preceding 4 months were treated with spironolactone 25 mg daily for 28 days. Serum potassium was measured before every haemodialysis during the study. Aldosterone and renin were measured at the beginning and end of the study. Patients were monitored for side effects. Data were examined with a paired t-test, with patients serving as their own controls and P < 0.05 considered significant. A sample size of 14 was required to achieve a power of 0.8 and a P = 0.05 to detect a potassium difference of 0.5 +/- 0.6 mEq/l. All patients were analysed as intention-to-treat. RESULTS: The mean potassium level was 4.6 +/- 0.6 mEq/l at baseline and 4.9 +/- 0.9 mEq/l at study completion (P = 0.14). Thirteen patients completed the trial with no potassium levels >6.0 mEq/l. Four patients had potassium levels between 5.5 and 6.0 mEq/l. One patient was withdrawn at day 20 after developing hyperkalaemia (7.6 mEq/l). Another patient was withdrawn at day 25 after missing a dialysis treatment. There were no differences in either baseline or 28 day aldosterone or renin levels (16.8 +/- 28.8 vs 11.7 +/- 6.1 ng/dl and 3.5 +/- 3.9 vs 3.5 +/- 3.5 ng/ml/h, respectively). Infrequent side effects included dry mouth, nosebleed, pruritis, gynecomastia and diarrhoea. No significant leukopenia or anaemia was noted. CONCLUSIONS: Spironolactone may be considered as a treatment option for selected chronic haemodialysis patients with heart disease. 相似文献
36.
Jeffrey F. Waring Rita Ciurlionis Robert A. Jolly Matthew Heindel Gerry Gagne Jane A. Fagerland Roger G. Ulrich 《Toxicology in vitro》2003,17(5-6):693-701
In vitro human hepatocyte cultures are a key tool in the investigation of xenobiotic toxicity and metabolism. In most in vitro hepatocyte studies, the cells are allowed to adhere to an extracellular matrix, such as collagen. Unfortunately, the ability of freshly isolated hepatocytes to adhere to collagen varies from donor to donor. We used microarray analysis to determine what gene expression differences exist between hepatocytes in suspension and hepatocytes attached to collagen. Results from different donors showed a considerable difference in gene expression patterns between the two hepatocyte populations. In addition, we also compared the gene expression profiles of hepatocytes in culture with liver tissue. The results showed that both hepatocytes in suspension and hepatocytes attached to collagen display significant gene expression differences compared with liver tissue. Finally, we show that both populations of hepatocytes are responsive to dexamethasone and regulate some of the same genes. Overall, our results suggest that either significant gene expression changes occur in isolated hepatocytes or that suspended and attached cells represent different populations of hepatocytes found in intact livers. 相似文献
37.
Rita Shiang Stephen G. Ryan Ya-Zhen Zhu Thomas J. Fielder Richard J. Allen Alan Fryer Sumimasa Yamashita Peter O'Connell John J. Wasmuth 《Annals of neurology》1995,38(1):85-91
Hyperekplexia is a rare, autosomal dominant neurological disorder characterized by hypertonia, especially in infancy, and by an exaggerated startle response. This disorder is caused by mutations in the ?1 subunit of the inhibitory glycine receptor (GLRA1). We previously reported two GLRA1 point mutations detected in 4 unrelated hyperekplexia families; both mutations were at nucleotide 1192 and resulted in the replacement of Arg271 by a glutamine (R271Q) in one case and a leucine (R271L) in the other. Here, 5 additional hyperekplexia families are shown to have the most common G-to-A transition mutation at nucleotide 1192. Haplotype analysis using polymorphisms within and close to the GLRA1 locus suggests that this mutation has arisen at least twice (and possibly four times). In 2 additional families, a third mutation is also presented that changes a tyrosine at amino acid 279 to a cysteine (Y279C). Five patients with atypical clinical features and equivocal or absent family history of hyperekplexia and 1 patient with a classical presentation but no family history are presented in whom a mutation in the GLRA1 gene was not detected. Thus, only clinically typical hyperekplexia appears to be consistently associated with GLRA1 mutations, and these affect a specific extracellular domain of the protein. 相似文献
38.
Henry M. Goodgold M.D. Rita C. Gentilcore Lynn Hendershott James W. Fletcher Larry D. Samuels 《European journal of nuclear medicine and molecular imaging》1986,12(5-6):271-273
To assess the significance of diffuse cardiac activity (DCA) seen on In-111 labeled leukocyte scans, we reviewed 87 studies performed over the last 4 years. Inflammatory cardiac conditions were seen as frequently in patients with DCA (15%) as those without (7%, P=0.3). There was a higher ratio of RBC:WBC in the final WBC preparation in the false-positive DCA group than the true positive DCA and no DCA groups. False-positive studies showing DCA are most likely due to residual blood pool activity.Presented in part, 70th annual meeting, Radiological Society of North America, Washington D.C., 25 November 1984 相似文献
39.
Sonography of testicular microlithiasis 总被引:1,自引:0,他引:1
Diego Jaramillo Antonio Perez-Atayde Rita Littlewood Teele M.D. 《Urologic radiology》1989,11(1):55-57
The sonographic appearance of testicular microlithiasis detected in a patient presenting with torsion is described. A "speckled" pattern of multiple, tiny bright echoes is produced by calcific concretions in the seminiferous tubules and seems to be characteristic of microlithiasis. Although this condition is not treatable, it should be recognized because it is often associated with extratesticular abnormalities and can obscure superimposed testicular disease. 相似文献
40.
John S Thompson Claire Pomeroy Richard J Kryscio Stephen A Brown Donna Reece Rita Kramer Dianna S Howard Gary VanZant Suzanne Humphries Gordon Phillips 《Biology of blood and marrow transplantation》2004,10(12):858-866
To reduce the toxicity of traditional conditioning regimens for allogeneic stem cell transplantation (allo-SCT), we used single-agent chemotherapy conditioning with either busulfan (total cumulative dose, 16 mg/kg) or melphalan (200 to 240 mg/m 2 ), followed by the anti-T cell-specific monoclonal antibody T10B9 (MEDI-500) daily for 3 days. T cell-replete SCT was performed from HLA-identical sibling donors. Acute graft-versus-host disease (aGVHD) prophylaxis consisted of 7 additional days of T10B9 and delayed onset of cyclosporine (ie, on day +4 or +5). Twenty-six high-risk hematologic malignancy patients were entered onto this study. All 24 patients who survived longer than 8 days engrafted, although 1 patient experienced late graft failure. Deaths occurred in 21 of 26 patients because of infection (n = 7), progression/recurrence of primary disease (n = 6), aGVHD (n = 4), regimen-related toxicity (n = 1), and other causes (n = 3). Five of these patients are enjoying disease-free survival with a median survival of 1193 days after allo-SCT. The conditioning regimen induced modulation of surface expression of CD3 (but not CD4 or CD8) and was associated with decreasing tumor necrosis factor-alpha (but not interleukin-6) serum levels. In conclusion, single-agent chemotherapy conditioning with T10B9 produced durable engraftment and long-term survival in some patients who would not have qualified for a traditional allo-SCT. 相似文献