全文获取类型
收费全文 | 19852篇 |
免费 | 1581篇 |
国内免费 | 72篇 |
专业分类
耳鼻咽喉 | 169篇 |
儿科学 | 652篇 |
妇产科学 | 539篇 |
基础医学 | 2976篇 |
口腔科学 | 296篇 |
临床医学 | 2251篇 |
内科学 | 3981篇 |
皮肤病学 | 609篇 |
神经病学 | 1986篇 |
特种医学 | 499篇 |
外科学 | 1950篇 |
综合类 | 159篇 |
一般理论 | 20篇 |
预防医学 | 2242篇 |
眼科学 | 349篇 |
药学 | 1205篇 |
中国医学 | 43篇 |
肿瘤学 | 1579篇 |
出版年
2024年 | 41篇 |
2023年 | 283篇 |
2022年 | 504篇 |
2021年 | 971篇 |
2020年 | 593篇 |
2019年 | 769篇 |
2018年 | 838篇 |
2017年 | 635篇 |
2016年 | 715篇 |
2015年 | 730篇 |
2014年 | 900篇 |
2013年 | 1161篇 |
2012年 | 1699篇 |
2011年 | 1727篇 |
2010年 | 872篇 |
2009年 | 757篇 |
2008年 | 1181篇 |
2007年 | 1186篇 |
2006年 | 1014篇 |
2005年 | 989篇 |
2004年 | 923篇 |
2003年 | 815篇 |
2002年 | 699篇 |
2001年 | 132篇 |
2000年 | 108篇 |
1999年 | 123篇 |
1998年 | 132篇 |
1997年 | 112篇 |
1996年 | 76篇 |
1995年 | 81篇 |
1994年 | 65篇 |
1993年 | 50篇 |
1992年 | 50篇 |
1991年 | 61篇 |
1990年 | 53篇 |
1989年 | 28篇 |
1988年 | 30篇 |
1987年 | 30篇 |
1986年 | 24篇 |
1985年 | 40篇 |
1984年 | 33篇 |
1983年 | 28篇 |
1982年 | 22篇 |
1981年 | 30篇 |
1980年 | 22篇 |
1979年 | 14篇 |
1978年 | 25篇 |
1976年 | 11篇 |
1974年 | 11篇 |
1973年 | 11篇 |
排序方式: 共有10000条查询结果,搜索用时 11 毫秒
21.
Phase I study of high-dose cytosine arabinoside and etoposide in patients with advanced malignancies
Bayard L. Powell Hyman B. Muss Robert L. Capizzi Mary E. Caponera Douglas R. White Patricia J. Zekan James N. Atkins Don V. Jackson Jr. Frederick Richards II John B. Craig Julia M. Cruz Charles L. Spurr 《Cancer chemotherapy and pharmacology》1987,19(3):250-252
Summary Cytosine arabinsodie (ara-C) and etoposide (VP-16) display synergy in the laboratory. Twenty-six patients participated in a phase I study of high-dose ara-C in combination with VP-16. The dose of VP-16 was held constant at 50 mg/m2 as an intermittent infusion over 33 h; escalating doses of ara-C were given as infusions during hours 9–12 and 21–24. Myelosuppression was the dose-limiting toxicity and occurred with doses considerably less than those expected from studies of the two drugs as single agents. The suggested initial doses for phase II trials with this schedule are 750 mg/m2×2 doses of ara-C and 50 mg/m2 of VP-16. Nonhematologic toxicity was minimal; therefore, further dose escalation is feasible in patients in whom myelosuppression is acceptable.Supported in part by grants from the National Cancer Institute (CA-12197 and CA-09422) and the American Cancer Society CF-85-182 相似文献
22.
Trawat Attarbaschi Julia Sacher Thomas Geiss-Granadia Nikolas Klein Nilufar Mossaheb Rupert Lanzenberger Susanne Asenbaum Robert Dudczak Siegfried Kasper Johannes Tauscher 《European neuropsychopharmacology》2007,17(2):102-107
We explored the relationship between striatal dopamine-2 (D(2)) receptor occupancy and extra-pyramidal symptoms (EPS) in bipolar patients receiving olanzapine. Seventeen patients with a DSM-IV diagnosis of bipolar disorder were treated with 5-45 mg/day olanzapine for at least 14 days. After that period, D(2) receptor occupancy was determined using Iodobenzamide (IBZM) and SPECT. EPS were assessed by the Simpson-Angus Scale (SAS) and Barnes-Akathisia Scale (BAS). We found a dose-dependent increase in occupancy: 5 mg led to 28-50%, 10 mg to 40-68%, 15 mg to 69%, 20 mg to 57-66%, 30 mg to 66% and 45 mg to 80% D(2) receptor occupancy; and a significant correlation between plasma levels and occupancy (R(2)=.55, P=.001). Similar to schizophrenic patients, bipolar patients did not exhibit EPS at D(2) occupancy levels of 28 to 80%. Although we did not find an increased vulnerability for acute EPS in bipolar patients receiving olanzapine at clinical relevant doses, this needs to be replicated with larger sample sizes. 相似文献
23.
Julia J. Rucklidge 《Journal of anxiety disorders》2009,23(6):836-840
Obsessive Compulsive Disorder (OCD) affects 0.5–2% of young people many of whom are resistant to conventional treatments. This case study describes an 18-year-old male with OCD who first underwent cognitive behavioral therapy (CBT) for a 1-year period with a modest response (his OCD had shifted from severe to moderate). Within a year, his anxiety had deteriorated back to the severe range and he now had major depression. He then entered an ABAB design trial using a nutritional formula consisting mainly of minerals and vitamins (together, known as micronutrients). After 8 weeks on the formula, his mood was stabilized, his anxiety reduced, and his obsessions were in remission. The treatment was then discontinued for 8 weeks, during which time his obsessions and anxiety worsened and his mood dropped. Reintroduction of the formula again improved the symptoms. This case illustrates the importance of considering the effect micronutrients have on mental illness. 相似文献
24.
25.
Balanced analgesia (an opioid and a nonsteroidal anti-inflammatory agent) after hysterectomy often leads to better postoperative pain outcomes. Researchers compared post-hysterectomy patients who received balanced analgesia with those who received only morphine patient-controlled analgesia, and their relationship with pain scores, ambulation, and hospital length of stay. 相似文献
26.
Rats undergoing extinction of lever-pressing for food after the attenuation of an external feedback for this behavior exhibit excessive lever-pressing unaccompanied by an attempt to collect a reward. This behavior may be analogous to the excessive and unreasonable behavior seen in obsessive-compulsive disorder. In the present study, we tested the hypothesis that the compulsive behavior induced by signal attenuation is mediated via D(1) rather than D(2) receptors. Administration of 0.005, 0.01 and 0.03 mg/kg of the D(1) antagonist SCH 23390 reduced the number of compulsive lever-presses without affecting the number of lever-presses followed by an attempt to collect a reward. In contrast, administration of 0.005, 0.01, 0.024, 0.036 and 0.05 of the D(2) antagonist haloperidol dose-dependently decreased both types of lever-presses. In addition, haloperidol at doses that decreased lever-pressing in the post-training signal attenuation procedure (0.036 and 0.05 mg/kg) had a similar effect in regular extinction, whereas an SCH 23390 dose that decreased compulsive lever-pressing in the post-training signal attenuation procedure (0.01 mg/kg) had no effect on regular extinction. On the basis of electrophysiological data on the response of dopamine neurons to the omission of an expected reward, these results were interpreted as suggesting that compulsive lever-pressing depends on a phasic decrease in the stimulation of D(1) receptors. The implications of these results for the pathophysiology and treatment of obsessive-compulsive disorder are discussed. 相似文献
27.
Terry Joe Sprinkle Julia F. Agee Russell B. Tippins C. Richard Chamberlain Guy B. Faguet George H. DeVries 《Brain research》1987,426(2):349-357
Monoclonal antibodies against human and bovine 2′:3′-cyclic nucleotide 3′-phosphodiesterase (CNPase) were generated by fusing FOX-NY myeloma cells with spleen cells from RBF/Dn mice previously immunized with the purified brain antigens. The enzyme isolated from bovine brain was quite basic, with an isoelectric point of 9.71 and both the bovine and human enzymes consisted of a closely spaced doublet at approximately 44 and 46 kDa on SDS-PAGE. Six monoclonals were identified as strongly recognizing the enzyme on both ELISA plates and on immunoblots of whole brain protein. Four monoclonals very weakly cross-reacted with guinea pig myelin basic protein. In contrast with two previous reports, some of our monoclonal antibodies did immunostain 2 or 3 protein bands in peripheral nerve, two bands closely corresponding to those immunostained in central nervous system (CNS) myelin, the Wolfgram protein fraction and in acetone powders of whole brain. Each of the 6 monoclonals reacting strongly on immunoblots recognized the enzyme in from 2 to 5 of the species examined (human, bovine, rat, mouse and rabbit). In addition, all 6 monoclonals that immunostained the enzyme in whole brain, myelin and Wolfgram protein immunoblots recognized both CNP1 (44 kDa) and CNP2 (46 kDa). The two closely spaced protein bands observed on SDS-PAGE and previously stained on immunoblots of CNS CNPase using polyvalent rabbit anti-bovine CNPase antisera, and now different monoclonal antibodies, appear to be immunologically related and to contain highly conserved sequences. 相似文献
28.
Juan M. Bellón MD Julia Buján MD Natalio G. Honduvilla MD Alvaro Hernando MD Jacinto Navlet MD 《Annals of vascular surgery》1995,9(3):266-273
Various methods of cryopreservation of human endothelial cells (EC) were studied to determine their viability and behavior when seeded onto vascular prostheses made of polytetrafluoroethylene (PTFE). Three different protocols were used: (1) cyropreservation of whole umbilical vein, (2) cyropreservation of freshly extracted umbilical EC in suspension, and (3) cryopreservation of EC derived from a first subculture. Fresh EC and EC from a first subculture were used as controls. The viability and growth of these cells in culture media were studied, and basal prostacyclin levels were determined. The cells were assessed morphologically after they were seeded onto PTFE discs. Our results showed that the cryopreservation method that maintained the greatest viability was that in which previously cultured EC were used. Basal prostacyclin levels were significantly different following cyropreservation. However, when these cells were seeded onto PTFE discs their behavior was similar to that of fresh EC.We thank W. L. Gore & Associates for supplying the prostheses used in this study.Supported by a grant from the Comision Interministerial de Cieucia y Tecnologia SAF 92/0875. 相似文献
29.
Semi-structured interviews were conducted with a cohort of 22 test applicants who requested Huntington's disease (HD) predictive testing in South Wales, and a random sample of 32 non-requesters, drawn from the South Wales HD register. Apart from identifying differences between the groups, the study afforded the opportunity to listen, at length, to at-risk individuals' accounts of living at risk and their thoughts about predictive testing and genetic services. Emergent themes included difficulties in family communication and the uncertainties inherent in being at risk and undergoing testing. Important factors in decision making about testing were: moral imperatives to clarify one's genetic status; views about the controllability of the future; family attitudes and norms; and the impact of a test result on family members. At-risk individuals' perceptions of the genetics service were that contact with the service would result in pressure to be tested and a need for test applicants to present a favourable view of coping capacities to secure testing. In addition, there was an expectation of ongoing contact with HD families at the initiative of the service providers. Implications of the findings for the way in which predictive testing services are structured and introduced to the at-risk population are discussed. 相似文献
30.