全文获取类型
收费全文 | 17427篇 |
免费 | 1172篇 |
国内免费 | 38篇 |
专业分类
耳鼻咽喉 | 121篇 |
儿科学 | 671篇 |
妇产科学 | 502篇 |
基础医学 | 2180篇 |
口腔科学 | 196篇 |
临床医学 | 2819篇 |
内科学 | 3028篇 |
皮肤病学 | 184篇 |
神经病学 | 1427篇 |
特种医学 | 286篇 |
外国民族医学 | 1篇 |
外科学 | 1360篇 |
综合类 | 574篇 |
一般理论 | 38篇 |
预防医学 | 2614篇 |
眼科学 | 345篇 |
药学 | 984篇 |
中国医学 | 12篇 |
肿瘤学 | 1295篇 |
出版年
2023年 | 89篇 |
2022年 | 137篇 |
2021年 | 329篇 |
2020年 | 218篇 |
2019年 | 325篇 |
2018年 | 340篇 |
2017年 | 252篇 |
2016年 | 326篇 |
2015年 | 396篇 |
2014年 | 497篇 |
2013年 | 818篇 |
2012年 | 1207篇 |
2011年 | 1287篇 |
2010年 | 621篇 |
2009年 | 576篇 |
2008年 | 1093篇 |
2007年 | 1219篇 |
2006年 | 1163篇 |
2005年 | 1173篇 |
2004年 | 1169篇 |
2003年 | 1107篇 |
2002年 | 1045篇 |
2001年 | 161篇 |
2000年 | 132篇 |
1999年 | 171篇 |
1998年 | 219篇 |
1997年 | 196篇 |
1996年 | 191篇 |
1995年 | 174篇 |
1994年 | 143篇 |
1993年 | 125篇 |
1992年 | 103篇 |
1991年 | 101篇 |
1990年 | 105篇 |
1989年 | 95篇 |
1988年 | 89篇 |
1987年 | 63篇 |
1986年 | 80篇 |
1985年 | 78篇 |
1984年 | 84篇 |
1983年 | 76篇 |
1982年 | 85篇 |
1981年 | 94篇 |
1980年 | 82篇 |
1979年 | 72篇 |
1978年 | 60篇 |
1977年 | 57篇 |
1976年 | 52篇 |
1974年 | 48篇 |
1973年 | 29篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Janet Simpson M PhD MCS AFBPsS 《Physiotherapy》1998,84(10):469-471
82.
Reflective inquiry in nursing practice or 'revealing images' 总被引:1,自引:0,他引:1
Penelope Cash Jenny Brooker Wendy Penney Janet Reinbold Laurence Strangio 《Nursing inquiry》1997,4(4):246-256
Reflective inquiry in nursing practice or 'revealing images' Nurses live and work in complex practice worlds; worlds of shrinking resources and expanding needs. Reflection through journaling offers unique opportunities to gain insight into practice. What might we learn from one's journal? A reflective journal can be a source of interplay between the self as written and the self as other. Likewise, the journal may act to situate ourselves in practice, while at the same time enabling us to illuminate how and in what ways our understandings have become distorted. The extent to which one's journal is educative depends upon the manner in which one chooses to use it as a transformative tool, a tool that might well be described as a process of healing and enlightenment. In order to illustrate the reflexive nature of journaling, this paper is presented as a play reading, where a conversation about practice stories between the different aspects of the nurse's self is depicted. In adopting a play reading, an alternative pedagogical tool is used to illustrate different methodologies exemplifying the emergence of how and in what ways we develop and reconstruct our understanding in nursing. 相似文献
83.
84.
85.
OBJECTIVE: Review the evidence for various explanations for microbiologic treatment failure following use of penicillin in group A streptococcal (GAS) tonsillopharyngitis. DATA SOURCE: Systematic review of the literature based on Medline and EMBASE searches, and review of reference lists of included studies. RESULTS: The explanations for penicillin treatment failure in GAS tonsillopharyngitis include 1) carrier state, 2) lack of compliance, 3) recurrent exposure, 4) in vivo copathogenicity of beta-lactamase-producing normal pharyngeal flora, 5) in vivo bacterial coaggregation, 6) poor antibiotic penetration to tonsillopharyngeal tissue, 7) in vivo eradication of normal protective flora, 8) early initiation of antibiotic therapy resulting in suppression of an adequate host immune response, 9) intracellular localization of GAS, 10) GAS tolerance to penicillin, 11) contaminated toothbrushes or orthodontic appliances, and 12) transmission from the family pet. There is very little type I or II evidence to support any of the above-cited explanations for treatment failure in GAS tonsillopharyngitis; available studies are mostly observational (in patients) or laboratory-based without clinical confirmation. CONCLUSION: Multiple explanations have been offered by investigators to explain penicillin treatment failures in GAS tonsillopharyngitis, but the evidence base to support the proposed explanations is generally weak by current standards. Further research is needed to better understand the mechanism(s) of penicillin treatment failure in GAS tonsillopharyngitis. 相似文献
86.
Dina Vivian Janet E. Fischel Robert M. Liebert 《Journal of behavior therapy and experimental psychiatry》1986,17(4):301-303
The case study reported in this paper focuses on the relationship between bedwetting and misconduct after the implementation of behavior therapy for both problems. A 6
-year-old girl was treated for enuresis and subsequently for conduct problems (lying, aggressiveness). After both bedwetting and misconduct displayed substantial and stable improvement, it was found that occasional nightly relapses in bedwetting were strongly associated with the occurence of misconduct the following day. Implications of this finding are discussed. 相似文献
87.
Jane Farmer Patrick Dawson Elizabeth Martin Janet Tucker 《Health services management research》2007,20(1):59-68
There is a wealth of material on 'how to do' change plus empirical work revealing change process complexity. In health care, the relevance of context is highlighted, but studies of rural health-care change have focused on community impacts. There is little to inform health-care managers of how remoteness and rurality impact upon change processes. This study considered Scottish maternity units and aimed to identify issues in the change process associated with rurality and remoteness. Six units were purposively selected and 131 interviews were conducted with managers, staff and community members over 15 months. Analysis induced themes pertinent to remoteness and rurality. These included: perceived 'distance' between senior managers imposing change and the wider community of staff and residents; perceptions of community vulnerability; and tensions arising from working in small teams and living in small communities. The study provides useful insights for rural managers at a time of considerable service reconfiguration. 相似文献
88.
Abstract We previously demonstrated that epidermal growth factor (EGF) induces a several-fold increase in ornithine decarboxylase (ODC) activity and the steady-state level of ODC mRNA in cultured SV40-transformed human keratinocytes (1). Pretreatment of cell cultures with ultraviolet B (UVB) radiation resulted in a reduction of EGF-induced ODC activity. To determine whether UVB inhibits the accumulation of ODC mRNA by EGF, cells were pretreated with 20 mJ/cm2 UVB or sham-irradiated and then incubated with 100 ng/ml EGF. Northern blot analysis revealed that UVB irradiation entirely blocked the EGF induction of ODC mRNA. Since the binding of EGF to its plasma membrane receptor is the first step in initiating a biological response, the effect of UVB on EGF binding was evaluated. UVB treatment of cultured keratinocytes resulted in an immediate and dose-dependent reduction of EGF binding. Scatchard analysis revealed thai the reduction of EGF binding was due to a 52% decrease in the number of available receptors, from 6.2 × 104/cell to 3.0 × 104/cell. However, UVB decreased the EGF-binding affinity very little (Kd = 0.60 nM in control and Kd=0.75 nM in UVB-treated Z114 cells). In addition, UVB did not alter the rate of EGF internalization. These data suggest that UVB blocks the signal transduction pathway of EGF that is involved in regulation of ODC gene expression. Immunoblot analysis of extracts from irradiated cells showed that UVB induced tyro-sine phosphorylation of EGFR and that the quantity of EGFR protein was unaffected by UVB treatment. Phosphorylation of EGFR may be responsible for decreased binding of EGF to its receptor. 相似文献
89.
M. H. de Vries F. A. M. Redegeld A. Sj. Koster J. Noordhoek J. G. de Haan R. P. J. Oude Elferink P. L. M. Jansen 《Naunyn-Schmiedeberg's archives of pharmacology》1989,340(5):588-592
Summary Recently, a mutant rat strain was described with a genetic defect for the biliary excretion of organic anions (TR– rats). To determine the possible heterogeneity of the transport systems in liver, intestine and kidney we investigated the transport of the anion 1-naphthol--d-glucuronide (1-NG) in isolated vascularly perfused organ preparations of the rat liver, intestine and kidney of both Wistar rats and TR– rats. 1-NG was administered as such (liver and kidney experiments) or formed intracellularly from 1-naphthol (1-N) (liver and gut experiments). Independent of the type of exposure to 1-NG, the biliary excretion was considerably impaired in TR– rats. In the intestine the total appearance and the vascular/luminal distribution pattern of 1-NG were not significantly different from the values in control rats. Furthermore, no significant disturbance was found with respect to the renal clearance of 1-NG in the TR– rat when compared with the Wistar rat. Thus, the genetic defect in the TR– rat is restricted to an impaired hepatobiliary excretion of 1-NG and does not affect the excretory systems of the intestine and kidney. These results suggest that the excretion of 1-NG by the liver, intestine and kidney involves distinct organ-specific transport systems. 相似文献
90.
M. H. de Vries G. A. Hofman A. Sj. Koster J. Noordhoek 《Naunyn-Schmiedeberg's archives of pharmacology》1989,340(2):239-245
Summary Using the isolated vascularly fluorocarbon emulsion perfused rat small intestine some factors which determine the extent of the intestinal glucuronidation of 1-naphthol to 1-naphthol--d-glucuronide were studied. Increasing the luminal 1-naphthol concentration resulted in a concomitant increase in the 1-naphthol appearance in the vascular perfusate. In contrast, the total appearance of 1-naphthol--d-glucuronide increased less than proportional to the increase in the luminal 1-naphthol concentration. About 88% of the total amount of 1-naphthol--d-glucuronide excreted was released into the vascular perfusate. The capacity-limited intestinal glucuronide efflux is most likely due to saturation of the excretory mechanism for 1-naphthol--d-glucuronide. Decreasing the vascular flow rate influenced both the appearance of 1-naphthol and 1-naphtol--d-glucuronide in the vascular perfusate, whereas the appearance of 1-naphthol--d-glucuronide in the luminal perfusate was essentially flow-independent. A noradrenaline-induced change in the haemodynamic state of the vascular bed (with the total flow kept constant) resulted in a marked decrease in the 1-naphthol vascular concentration. The vascular 1-naphthol--d-glucuronide concentration was only slightly affected. These results indicate that changes in blood flow and blood flow distribution within the intestinal wall can affect the extent of presystemic intestinal metabolism by interfering with the absorption of the parent compound and the efflux of formed conjugates. These parameters can be of paramount importance for causing variable intestinal first-pass effects of drugs in vivo.
Send offprint requests to M. H. de Vries at the above address 相似文献