全文获取类型
收费全文 | 3439篇 |
免费 | 190篇 |
国内免费 | 15篇 |
专业分类
耳鼻咽喉 | 45篇 |
儿科学 | 116篇 |
妇产科学 | 41篇 |
基础医学 | 479篇 |
口腔科学 | 244篇 |
临床医学 | 284篇 |
内科学 | 783篇 |
皮肤病学 | 122篇 |
神经病学 | 207篇 |
特种医学 | 183篇 |
外科学 | 295篇 |
综合类 | 57篇 |
一般理论 | 2篇 |
预防医学 | 387篇 |
眼科学 | 65篇 |
药学 | 231篇 |
中国医学 | 19篇 |
肿瘤学 | 84篇 |
出版年
2023年 | 20篇 |
2022年 | 57篇 |
2021年 | 99篇 |
2020年 | 77篇 |
2019年 | 95篇 |
2018年 | 139篇 |
2017年 | 69篇 |
2016年 | 88篇 |
2015年 | 109篇 |
2014年 | 154篇 |
2013年 | 190篇 |
2012年 | 271篇 |
2011年 | 282篇 |
2010年 | 171篇 |
2009年 | 143篇 |
2008年 | 164篇 |
2007年 | 214篇 |
2006年 | 143篇 |
2005年 | 146篇 |
2004年 | 85篇 |
2003年 | 74篇 |
2002年 | 68篇 |
2001年 | 63篇 |
2000年 | 46篇 |
1999年 | 47篇 |
1998年 | 56篇 |
1997年 | 50篇 |
1996年 | 51篇 |
1995年 | 42篇 |
1994年 | 29篇 |
1993年 | 37篇 |
1992年 | 31篇 |
1991年 | 28篇 |
1990年 | 22篇 |
1989年 | 32篇 |
1988年 | 25篇 |
1987年 | 16篇 |
1986年 | 18篇 |
1985年 | 25篇 |
1984年 | 11篇 |
1983年 | 18篇 |
1981年 | 14篇 |
1980年 | 8篇 |
1979年 | 10篇 |
1978年 | 12篇 |
1977年 | 14篇 |
1976年 | 11篇 |
1973年 | 7篇 |
1969年 | 9篇 |
1967年 | 8篇 |
排序方式: 共有3644条查询结果,搜索用时 0 毫秒
31.
David AC Leggett Kenneth A Miles Benjamin B Kelley 《Journal of Medical Imaging and Radiation Oncology》1998,42(4):335-340
Five cases of cerebral glioma are presented here that illustrate the benefit of functional CT imaging of blood-brain barrier permeability and cerebral blood volume. Functional CT uses Patlak analysis of a single location dynamic sequence to extract physiological information that is useful clinically in the assessment of cerebral gliomas. Functional CT offers distinct advantages over other functional modalities including clearer delineation of tumour, tumour grading, measurement of tumour activity and monitoring response to therapy. 相似文献
32.
João Freitas M.D. Rosa Santos B.Sc. Elsa Azevedo M.D. Ovidio Costa Ph.D. Mário Carvalho M.D. A. Falcão de Freitas M.D. Ph.D F.E.S.C. 《Clinical autonomic research》2000,10(5):293-299
Orthostatic intolerance is the development of disabling symptoms upon assuming an upright posture that are relieved partially by resuming the supine position. Postural tachycardia syndrome (POTS) is an orthostatic intolerance syndrome characterized by palpitations because of excessive orthostatic sinus tachycardia, lightheadedness, tremor, and near-syncope. Patients usually undergo extensive medical, cardiac, endocrine, neurologic, and psychiatric evaluation, which usually fails to identify a specific abnormality. The authors investigated the autonomic and hemodynamic profile of patients with POTS and the effectiveness of bisoprolol and fludrocortisone. The authors evaluated 11 female patients with POTS before and after medical treatment with a cardioselective bisoprolol -blocker or fludrocortisone, or both, and 11 age-matched control patients. Variability of heart rate and systolic blood pressure was assessed by fast Fourier transform, and spontaneous baroreceptor gain was assessed by use of the temporal sequences slope and index. Modelflow was used to quantify hemodynamics. Symptoms in all patients improved greatly after medication. The autonomic and hemodynamic impairment observed in patients with POTS, particularly after orthostatic stress, is treated effectively with bisoprolol or fludrocortisone or both. These results need further confirmation in a controlled double-blind study. Proper medical treatment improves dramatically the clinical and autonomic-hemodynamic disturbances observed in patients with POTS. The data support the hypothesis that POTS is the result of a hyperadrenergic activation or hypovolemia during orthostasis. 相似文献
33.
Dr. Azevedo Neves 《Journal of cancer research and clinical oncology》1908,7(1):180-183
Ohne Zusammenfassung 相似文献
34.
Ohne ZusammenfassungDiese. Arbeit ist ein Auszug aus dem Bericht, der von dem Autor der portugiesischen Kommission für Krebsforschung eingereicht wurde, eine Ergänzung des Aufsatzes des Verfassers auf S. 180 dieses Bandes der Zeitschrift. 相似文献
35.
36.
Enio R Vasques Estela RR Figueira Joel A Rocha-Filho Cinthia Lanchotte Jorge LS Ximenes Helena B Nader Ivarne LS Tersariol Marcelo A Lima Tiago Rodrigues José EM Cunha Eleazar Chaib Luiz AC D'Albuquerque Flávio HF Galv?o 《Hepatobiliary & pancreatic diseases international : HBPD INT》2022,21(2):190-192
<正>To the Editor:Ischemia-reperfusion injury following surgery and transplantation can lead to irreversible multiorgan failure.Intracellular calcium overload is associated to cellular death during ischemiareperfusion.A recently discovered heparin fragment (HF),trisulfated disaccharide (TD),that acts on sodium-calcium exchanger(NCX) decreasing intracellular Ca2+,showed effectiveness on protecting hepatocytes from ischemia-reperfusion injury [1], 相似文献
37.
38.
Red blood cell (RBC) protein 4.2 deficiency is often associated with a moderate nonimmune hemolytic anemia, splenomegaly, and osmotically fragile RBCs resembling, but not identical to, hereditary spherocytosis (HS). In the Japanese type of protein 4.2 deficiency (protein 4.2Nippon), the anemia is associated with a point mutation in the protein 4.2 cDNA. In this report, we describe a patient with moderate and apparently episodic nonimmune hemolytic anemia with splenomegaly, spherocytosis, osmotically fragile RBCs, reduced whole cell deformability, and abnormally dense cells. Sodium dodecyl sulfate- polyacrylamide gel electrophoresis analysis of the proposita's RBC membrane proteins showed an 88% deficiency of protein 4.2 and a 30% deficiency of glyceraldehyde-3-phosphate dehydrogenase (band 6). Structural and molecular analyses of the proposita's protein 4.2 were normal. In contrast, limited tryptic digestion of the proposita's band 3 showed a homozygous abnormality in the cytoplasmic domain. Analysis of the pedigree disclosed six members who were heterozygotes for the band 3 structural abnormality and one member who was a normal homozygote. Direct sequence analysis of the abnormal band 3 tryptic peptide suggested that the structural abnormality resided at or near residue 40. Sequence analysis of the proposita's band 3 cDNA showed a 232G-->A mutation resulting in a 40glutamic acid-->lysine substitution (band 3Montefiore). Allele-specific oligonucleotide hybridization was used to probe for the mutation in the pedigree, showing that the proposita was homozygous, and the pedigree members who were heterozygous for the band 3 structural abnormality were also heterozygous for the band 3Montefiore mutation. The band 3Montefiore mutation was absent in 26 chromosomes from race-matched controls and in one pedigree member who did not express the band 3 structural abnormality. In coincidence with splenectomy, the proposita's anemia was largely corrected along with the disappearance of most spherocytes and considerable improvements of RBC osmotic fragility, whole cell deformability, and cell density. We conclude that this hereditary hemolytic anemia is associated with the homozygous state for band 3Montefiore (40glutamic acid-->lysine) and a decreased RBC membrane content of protein 4.2. We speculate that band 3 structural abnormalities can result in defective interactions with protein 4.2 and band 6, and in particular, that the region of band 3 containing 40glutamic acid is involved directly or indirectly in interactions with these proteins. 相似文献
39.
40.