全文获取类型
收费全文 | 6468篇 |
免费 | 440篇 |
国内免费 | 13篇 |
专业分类
耳鼻咽喉 | 35篇 |
儿科学 | 96篇 |
妇产科学 | 100篇 |
基础医学 | 915篇 |
口腔科学 | 155篇 |
临床医学 | 779篇 |
内科学 | 1283篇 |
皮肤病学 | 66篇 |
神经病学 | 645篇 |
特种医学 | 184篇 |
外科学 | 858篇 |
综合类 | 133篇 |
现状与发展 | 1篇 |
一般理论 | 5篇 |
预防医学 | 714篇 |
眼科学 | 115篇 |
药学 | 492篇 |
中国医学 | 10篇 |
肿瘤学 | 335篇 |
出版年
2023年 | 34篇 |
2022年 | 68篇 |
2021年 | 162篇 |
2020年 | 101篇 |
2019年 | 155篇 |
2018年 | 161篇 |
2017年 | 110篇 |
2016年 | 138篇 |
2015年 | 163篇 |
2014年 | 213篇 |
2013年 | 272篇 |
2012年 | 447篇 |
2011年 | 443篇 |
2010年 | 233篇 |
2009年 | 226篇 |
2008年 | 381篇 |
2007年 | 391篇 |
2006年 | 384篇 |
2005年 | 401篇 |
2004年 | 361篇 |
2003年 | 324篇 |
2002年 | 286篇 |
2001年 | 125篇 |
2000年 | 146篇 |
1999年 | 104篇 |
1998年 | 52篇 |
1997年 | 59篇 |
1996年 | 41篇 |
1995年 | 53篇 |
1994年 | 38篇 |
1993年 | 30篇 |
1992年 | 65篇 |
1991年 | 70篇 |
1990年 | 69篇 |
1989年 | 61篇 |
1988年 | 53篇 |
1987年 | 51篇 |
1986年 | 45篇 |
1985年 | 36篇 |
1984年 | 41篇 |
1983年 | 38篇 |
1982年 | 23篇 |
1979年 | 27篇 |
1978年 | 17篇 |
1975年 | 14篇 |
1974年 | 18篇 |
1973年 | 24篇 |
1972年 | 20篇 |
1971年 | 15篇 |
1970年 | 12篇 |
排序方式: 共有6921条查询结果,搜索用时 15 毫秒
71.
Andrea Haldane Graeme J. Finlay John B. Gavin Bruce C. Baguley 《Cancer chemotherapy and pharmacology》1992,29(6):475-479
Summary The cytotoxicity ofN-[2-(dimethylamino)ethyl]acridine-4-carboxamide (AC; NSC 601 316), a new experimental DNA-intercalating antitumour drug, against a cultured Lewis lung adenocarcinoma cell line was compared with that of the DNA-intercalating antitumour drug amsacrine. In contrast to amsacrine, AC demonstrated self-inhibition of cytotoxicity following short (3–9 h) incubation periods and exponential killing (with a shoulder) after long (24–72 h) periods of incubation. The difference between these drugs was best demonstrated using a constant concentration x time (CxT) exposure (AC, 12 mol h l–1; amsacrine, 3 mol h l–1). In contrast to amsacrine, AC was minimally effective over exposure periods of 1 h and maximally effective over intermediate periods (4–6 h). The results suggest the possibility of designing AC administration protocols that maximise the drug's cytotoxicity towards solid tumours, which, because of diffusion barriers, are subjected to longer drug exposures than are well-vascularised tumours.Supported by the Auckland Division of the Cancer Society of New Zealand and by the Health Research Council of New Zealand 相似文献
72.
L Matheson V Mooney V Caiozzo G Jarvis J Pottinger C DeBerry K Backlund K Klein J Antoni 《Spine》1992,17(8):914-921
Although isokinetic strength testing has been in use for more than two decades, and numerous studies have addressed isokinetic performance of the lumbar spine, the effect of instructions on isokinetic trunk strength has not been studied. In a sample of 30 healthy women, this study examined the effect of "high-demand" instructions on lumbar strength performance. High-demand instructions were found to have a substantial positive effect on performance variability, reliability, absolute magnitude, and validity. Under these conditions, isokinetic trunk strength was found to be predictive of performance in a frequent lifting-lowering task. 相似文献
73.
N E Mooney 《The Nursing clinics of North America》1991,26(1):73-87
Pain is a familiar phenomenon to all orthopedic nurses. As Dunwoody said, "Few things we do for patients are more fundamental to the quality of life than relieving pain." We as orthopedic nurses are in a position to contribute to the positive management of pain by using a comprehensive approach to pain management that involves the participation of the patient. We need to believe the patient's pain, try new approaches, and help our patients achieve pain relief. 相似文献
74.
Beatrice M Seddon Geoffrey S Payne Laura Simmons Ruth Ruddle Rachel Grimshaw Siew Tan Alison Turner Florence Raynaud Gavin Halbert Martin O Leach Ian Judson Paul Workman 《Clinical cancer research》2003,9(14):5101-5112
PURPOSE: To perform a Phase I study of SR-4554, a fluorinated 2-nitroimidazole noninvasive probe of tumor hypoxia detected by (19)F magnetic resonance spectroscopy (MRS). EXPERIMENTAL DESIGN: SR-4554 administration, on days 1 and 8, was followed by plasma sampling for pharmacokinetic studies and by three MRS studies performed over 24 h on days 8 and 9. Unlocalized MR spectra were acquired from tumor (10- or 16-cm dual resonant 1H/19F surface coil; 1.5 T Siemens Vision MR system; 2048 transients acquired over 34 min; 1.28-ms adiabatic pulse; repetition time, 1 s). Plasma drug concentrations were measured with a validated high-performance liquid chromatography method. Noncompartmental pharmacokinetic analysis was performed. RESULTS: Eight patients underwent pharmacokinetic studies, receiving doses of SR-4554 of 400-1600 mg/m(2). Peak plasma concentrations increased linearly with the SR-4554 dose (r(2) = 0.80; P = 0.0002). The plasma elimination half-life was relatively short (mean +/- SD, 3.28 +/- 0.59 h), and plasma clearance was quite rapid (mean +/- SD, 12.8 +/- 3.3 liters/h). Urinary recovery was generally high. SR-4554 was well tolerated. A single patient experienced dose-limiting toxicity (nausea and vomiting) at 1600 mg/m(2). The maximum tolerated dose was 1400 mg/m(2). SR-4554 was detected spectroscopically in tumors immediately after infusion at doses of 400-1600 mg/m(2). At the highest dose (1600 mg/m(2)), SR-4554 was detectable in tumor at 8 h, but not at 27 h. CONCLUSIONS: SR-4554 has plasma pharmacokinetic and toxicity profiles suitable for use as a hypoxia probe. It can be detected in tumors by unlocalized MRS. Additional clinical studies are warranted. 相似文献
75.
N. A. Shorter M. D. Thompson D. P. Mooney J. F. Modlin 《Pediatric surgery international》1997,13(1):2-5
Eleven patients with Yersinia enterocolitica infections were identified in the Upper Valley of New Hampshire and Vermont during October and November of 1995. Three children
presented with an appendicitis-like picture. Two underwent appendectomy, one of whom was the outbreak's index case. Both appendectomy
patients presented with lower abdominal pain, fever, vomiting, and a right lower quadrant mass associated with leukocytosis.
Both had terminal ileitis, and in both, cultures of peritoneal fluid and a mesenteric lymph node grew Y. enterocolitica. Even during an outbreak there is no consistently reliable nonoperative way to separate a sporadic case of appendicitis from
one whose appendicitis-like symptoms are due to Yersinia. In addition, a small percentage of Yersinia patients will present with true appendicitis as a complication of their disease.
Accepted: 20 January 1997 相似文献
76.
77.
Jararhagin is a 52 kDa hemorrhagic P-III metalloproteinase isolated from the venom of the medically important Brazilian pit-viper Bothrops jararaca. It is a member of the reprolysin family of zinc metalloproteinases containing a catalytic metalloproteinase domain followed by a disintegrin-like and a cysteine-rich domain. The impact of jararhagin on hemostasis has been extensively studied using in vitro and in vivo model systems as well as in clinical studies. Jararhagin-induced hemorrhage is the result of the degradation of sub-endothelial matrix proteins leading to the disruption of the blood vessel endothelium, with accompanying disturbances in platelet function. The versatility of jararhagin is further demonstrated by its direct action on von Willebrand factor, the degradation of fibrinogen, by its inhibition of platelet adhesion to collagen and by its inability to be affected by the plasma inhibitor 2-macroglobulin. Collagen-induced platelet aggregation is inhibited by jararhagin though the binding of the molecule to the 2 subunit I domain of the platelet surface 2β1 integrin (collagen receptor). Jararhagin also cleaves the β1 subunit of the same integrin, inhibiting platelet interaction and ultimately causing impairment of signal transduction. The effect of jararhagin on cell systems other than platelets is evaluated; in fibroblasts, jararhagin functions as a collagen-mimetic substrate and, in endothelial cells, it causes apoptosis and indirectly inhibits cell proliferation by release of angiostatin-like compounds. Jararhagin induces a strong pro-inflammatory response characterized by intense leukocyte accumulation at the site of the injection. Although hemorrhage and edema are a response to the direct effect of jararhagin, jararhagin-induced inflammation and necrosis are dependent on macrophages and key pro-inflammatory cytokines or their receptors. Some data also indicate that the toxin possesses anti-tumorgenic properties. Methods for inhibiting jararhagin are reviewed; this encompasses the use of synthetic peptides to the isolation of naturally occurring mammalian peptides and the development of toxin-specific antibodies through DNA immunisation and monoclonal antibody technologies. The availability of jararhagin makes it an important tool for research into the mechanisms of action of similar toxins, for insights into cellular interactions and for clinical investigations into the treatment of envenomings from B. jararaca. 相似文献
78.
Neuronal activities following olfactory bulb electrical stimulation were examined before and after administration of dopamine and dopamine antagonist in the rat olfactory tubercle. The inhibitory response to olfactory bulb stimulation was attenuated by systemic haloperidol administration, but the excitatory response to olfactory bulb stimulation rarely was modulated. Topical application of dopamine by iontophoresis extended the duration of inhibition in 56% of the neurons sampled and diminished it in 25%; the excitatory response was modulated in 42% of neurons, most of which were attenuated. These findings suggest that dopamine in the olfactory tubercle could be involved in modulations of neuronal activities related to olfactory transduction. 相似文献
79.
80.
Anne Lesack Laurie W. Smith C. Sarai Racey Lovedeep Gondara Mel Krajden Marette Lee Ruth Elwood Martin Gavin Stuart Stuart Peacock Eduardo L. Franco Dirk van Niekerk Gina S. Ogilvie 《Current oncology (Toronto, Ont.)》2022,29(6):3860
Self-collection may provide an opportunity for innovation within population-based human papillomavirus (HPV) cervical cancer screening programs by providing an alternative form of engagement for all individuals. The primary objective was to determine willingness to self-collect a vaginal sample for primary HPV screening and factors that impact willingness in individuals who participated in the Human Papillomavirus For Cervical Cancer (HPV FOCAL) screening trial, a large randomized controlled cervical screening trial. A cross-sectional online survey was distributed between 2017 and 2018 to 13,176 eligible participants exiting the FOCAL trial. Bivariate and multivariable logistic regression assessed factors that influence willingness to self-collect on 4945 respondents. Overall, 52.1% of respondents indicated willingness to self-collect an HPV sample. In multivariable analysis, the odds of willingness to self-collect were significantly higher in participants who agreed that screening with an HPV test instead of a Pap test was acceptable to them (odds ratio (OR): 1.45 (95% confidence interval (CI): 1.15, 1.82), those who indicated that collecting their own HPV sample was acceptable to them (p < 0.001), and those with higher educational ascertainment (OR: 1.31, 95% CI: 1.12, 1.54). The findings offer insight into the intentions to self-collect in those already engaged in screening, and can inform cervical cancer screening programs interested in offering alternative approaches to HPV-based screening. 相似文献