全文获取类型
收费全文 | 13101篇 |
免费 | 1320篇 |
国内免费 | 96篇 |
专业分类
耳鼻咽喉 | 99篇 |
儿科学 | 542篇 |
妇产科学 | 239篇 |
基础医学 | 1694篇 |
口腔科学 | 251篇 |
临床医学 | 1665篇 |
内科学 | 2647篇 |
皮肤病学 | 183篇 |
神经病学 | 1169篇 |
特种医学 | 714篇 |
外科学 | 1426篇 |
综合类 | 764篇 |
一般理论 | 13篇 |
预防医学 | 1227篇 |
眼科学 | 355篇 |
药学 | 792篇 |
2篇 | |
中国医学 | 3篇 |
肿瘤学 | 732篇 |
出版年
2023年 | 61篇 |
2022年 | 109篇 |
2021年 | 223篇 |
2020年 | 146篇 |
2019年 | 195篇 |
2018年 | 314篇 |
2017年 | 190篇 |
2016年 | 195篇 |
2015年 | 198篇 |
2014年 | 300篇 |
2013年 | 505篇 |
2012年 | 533篇 |
2011年 | 535篇 |
2010年 | 407篇 |
2009年 | 352篇 |
2008年 | 506篇 |
2007年 | 607篇 |
2006年 | 585篇 |
2005年 | 572篇 |
2004年 | 493篇 |
2003年 | 455篇 |
2002年 | 464篇 |
2001年 | 451篇 |
2000年 | 432篇 |
1999年 | 399篇 |
1998年 | 266篇 |
1997年 | 269篇 |
1996年 | 272篇 |
1995年 | 235篇 |
1994年 | 205篇 |
1993年 | 214篇 |
1992年 | 306篇 |
1991年 | 303篇 |
1990年 | 315篇 |
1989年 | 284篇 |
1988年 | 251篇 |
1987年 | 271篇 |
1986年 | 230篇 |
1985年 | 192篇 |
1984年 | 175篇 |
1983年 | 144篇 |
1982年 | 119篇 |
1981年 | 90篇 |
1980年 | 90篇 |
1979年 | 112篇 |
1978年 | 105篇 |
1977年 | 97篇 |
1976年 | 90篇 |
1975年 | 84篇 |
1970年 | 57篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
NPC 15437 is a prototype member of a new class of synthetically derived protein kinase C (PKC) inhibitors. PKC activity and binding of phorbol ester to the enzyme were inhibited by NPC 15437, with IC50 values of 19 +/- 2 microM and 23 +/- 4 microM, respectively. No inhibition of cAMP-dependent or calcium/calmodulin-dependent protein kinases was observed at concentrations of NPC 15437 up to 300 microM. To investigate the mechanism by which NPC 15437 exerts its effects, a kinetic analysis of the inhibition with respect to three activators of the enzyme, phosphatidylserine, calcium, and phorbol ester, was performed. NPC 15437 was a competitive inhibitor of the activation of PKC by phorbol ester (Ki = 5 +/- 3 microM). Stimulation of PKC alpha by phosphatidylserine was competitively inhibited by NPC 15437 (Ki = 12 +/- 4 microM). The inhibition was mixed with respect to activation by calcium. These results suggest that NPC 15437 is a selective inhibitor of PKC, interacting at the regulatory region of the enzyme. NPC 15437 inhibited PKC in intact cells, dose-dependently antagonizing the phorbol ester-induced phosphorylation of a 47-kDa protein in human platelets. 相似文献
62.
63.
Jean-Francois Légaré Ansar Hassan Karen J Buth John A Sullivan 《Journal of cardiothoracic surgery》2007,2(1):44-8
Background
While it is believed that total arterial grafting (TAG) for coronary artery bypass grafting (CABG) confers improved long-term outcomes when compared to conventional grafting with left internal mammary artery and saphenous vein grafts (LIMA+SVG), to date, this has not become the standard of care. In this study, we assessed the impact of TAG on medium-term outcomes after CABG. 相似文献64.
Sean Sullivan 《International journal of mental health and addiction》2007,5(4):381-389
The EIGHT Screen is a brief problem gambling screen originally designed for use by family doctors. Its wider use indicated
the need for further validation. A triangulated approach used a range of measures in different settings in both the current
study and findings from a number of earlier projects, and reviewed current use. The EIGHT Screen had acceptable correlations
with the SOGS (r = 74–90%) and with the NODS-12 months Screen (r = 62.4%). Measurements remained relatively constant amongst a range of cultures, settings, age and gender, while few false
positives were produced by the screen. The EIGHT Screen appears to be a valid tool for untrained users to identify Level 2
and 3 problem gambling in a wide range of cultures and settings. 相似文献
65.
P Iranzo MM Alsina I Martínez-De Pablo S Segura JM Mascaró C Herrero 《Journal of the European Academy of Dermatology and Venereology》2007,21(7):902-907
BACKGROUND: The mainstay of treatment for pemphigus is systemic corticosteroids. Different adjuvants have been used to reduce side-effects of long-term corticotherapy. Gold is an anti-inflammatory drug used in autoimmune diseases, whose use has waned with the advent of new immunosuppressive agents. OBJECTIVE: To study the outcome of the use of intramuscular gold treatment of pemphigus vulgaris refractory to previous therapies. METHODS: Thirteen patients with pemphigus vulgaris who had failed to respond to several prior therapies were treated with aurothiomalate, as a steroid-sparing agent. Patients were monitored to assess disease activity and gold toxicity. RESULTS: Seven patients achieved complete remission. Four patients were able to taper prednisone doses, although pemphigus flared when prednisone was discontinued or reduced. Toxicity was observed in the other two patients. CONCLUSIONS: In 53.4% of the patients, the use of chrysotherapy resulted in the complete clearing of the disease, discontinuation of all systemic therapies and induced a long-term clinical remission. Prednisone doses were able to be reduced in the remaining 46.6%. Any side-effects were reversible with drug discontinuation. Gold therapy showed efficacy as a secondary line treatment in refractory pemphigus vulgaris. 相似文献
66.
67.
68.
K. L. Preston K. L. Preston E. C. Strain G. E. Bigelow J. T. Sullivan K. L. Preston 《Psychopharmacology》1996,123(1):15-25
The present study was conducted to determine whether methadone maintenance alters the pharmacodynamic effects of single doses of cocaine. Twenty-two current users of IV cocaine who were not seeking treatment for their illicit cocaine use participated while living on a research unit. Eleven were maintained on methadone 50 mg PO daily as treatment for their opioid abuse; 11 were opioid abusers who were not physically dependent on opioids and who provided opioid-free urines throughout the study. Each subject received acute cocaine challenge doses of 0, 12.5, 25, and 50 mg intravenously in random order under double-blind conditions in separate test sessions. Physiologic and subject-rated responses were measured before injection and for 2 h after. In the methadone maintenance group, cocaine challenge sessions occurred 15.5 h after the daily methadone dose. There were significant differences between the methadone-dependent and nondependent groups: 1) baseline differences related to chronic methadone administration and not associated with cocaine administration (lower respiration rates and pupil diameter; higher skin temperature) and 2) differences in response to cocaine administration; cocaine-induced increases in subject ratings of Drug Effect, Rush, Good Effects, Liking, and Desire for Cocaine and in heart rate were greater in the methadone maintenance patients compared to the non-dependent group. These results indicate that the positive subjective effects and some physiological effects of cocaine are enhanced in methadone-maintained individuals, suggesting a pharmacological basis for the high rates of cocaine abuse among methadone maintenance patients.Some of these data were presented at the annual meeting of the Committee on Problems of drug Dependence, Keystone, Colorado, June 1992 相似文献
69.
JI Elizalde ; J Clemente ; JL Marin ; J Panes ; B Aragon ; A Mas ; JM Pique ; J Teres 《Transfusion》1997,37(6):573-576
BACKGROUND: Equilibration of hemoglobin concentration after transfusion has been estimated to take about 24 hours, but some studies have shown that earlier measurements reflect steady-state values in persons who have not bled recently. This study was aimed at assessing the changes over time in hemoglobin concentration after transfusion in acutely anemic patients because of recent bleeding. STUDY DESIGN AND METHODS: Thirty-two normovolemic patients recovering from an acute bleeding episode who were no longer thought to be bleeding and who received a 2- unit red cell transfusion were studied. At baseline and 15, 30, 60, and 120 minutes and 24 hours after transfusion, hemoglobin concentration and hematocrit values were measured. RESULTS: The administration of 2 units of packed red cells elicited a 24-hour increase of 22.4 +/− 6.8 g per L in hemoglobin concentration. Hemoglobin values were not different at any of the defined posttransfusion times. Hematocrit levels experienced similar changes over time. Agreement between 15-minute and 24-hour values was excellent, as only 6 percent of patients exhibited a clinically significant difference (> 6 g/L) between the hemoglobin measurements. CONCLUSION: Hemoglobin and hematocrit values rapidly equilibrate after transfusion in normovolemic patients who are recovering from an acute bleeding episode. This fact would allow a rapid assessment of the effects of transfusion and of the recurrence of bleeding in patients remaining at risk. 相似文献
70.