全文获取类型
收费全文 | 11052篇 |
免费 | 2698篇 |
国内免费 | 133篇 |
专业分类
耳鼻咽喉 | 398篇 |
儿科学 | 294篇 |
妇产科学 | 311篇 |
基础医学 | 354篇 |
口腔科学 | 266篇 |
临床医学 | 3099篇 |
内科学 | 1977篇 |
皮肤病学 | 528篇 |
神经病学 | 840篇 |
特种医学 | 396篇 |
外科学 | 1504篇 |
综合类 | 466篇 |
现状与发展 | 2篇 |
一般理论 | 1篇 |
预防医学 | 1921篇 |
眼科学 | 139篇 |
药学 | 287篇 |
1篇 | |
中国医学 | 103篇 |
肿瘤学 | 996篇 |
出版年
2024年 | 63篇 |
2023年 | 419篇 |
2022年 | 125篇 |
2021年 | 277篇 |
2020年 | 510篇 |
2019年 | 192篇 |
2018年 | 606篇 |
2017年 | 633篇 |
2016年 | 651篇 |
2015年 | 731篇 |
2014年 | 742篇 |
2013年 | 1096篇 |
2012年 | 472篇 |
2011年 | 441篇 |
2010年 | 577篇 |
2009年 | 689篇 |
2008年 | 380篇 |
2007年 | 324篇 |
2006年 | 391篇 |
2005年 | 284篇 |
2004年 | 248篇 |
2003年 | 188篇 |
2002年 | 194篇 |
2001年 | 237篇 |
2000年 | 181篇 |
1999年 | 207篇 |
1998年 | 297篇 |
1997年 | 313篇 |
1996年 | 332篇 |
1995年 | 262篇 |
1994年 | 189篇 |
1993年 | 132篇 |
1992年 | 125篇 |
1991年 | 125篇 |
1990年 | 110篇 |
1989年 | 128篇 |
1988年 | 122篇 |
1987年 | 104篇 |
1986年 | 83篇 |
1985年 | 94篇 |
1984年 | 78篇 |
1983年 | 77篇 |
1982年 | 54篇 |
1981年 | 58篇 |
1980年 | 29篇 |
1979年 | 32篇 |
1978年 | 25篇 |
1976年 | 25篇 |
1975年 | 26篇 |
1971年 | 24篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
Assault-injured Adolescents Presenting to the Emergency Department: Causes and Circumstances 总被引:1,自引:0,他引:1
32.
33.
N. E. McCarthy H. A. Jones N. A. Marks R. J. Shiner P. W. Ind H. O. Al-Hassi N. R. English C. M. Murray J. R. Lambert S. C. Knight A. J. Stagg 《Clinical and experimental allergy》2007,37(1):72-82
Background Dendritic cells (DC) mediate inflammation in rodent models of allergic airway disease, but the role played by human respiratory‐tract DC (hRTDC) in atopic asthma remains poorly defined. Recent data suggest that CD1 antigen presentation by hRTDC may contribute to asthma pathogenesis. Objective To investigate the influence of hRTDC on the balance between atopy and allergic asthma in human subjects and to determine whether CD1 expression by hRTDC is modulated during asthmatic inflammation. Methods Sputum cells were induced from steroid‐naïve, allergen‐challenged and allergen‐naïve subjects (atopic asthmatics, atopic non‐asthmatics and non‐atopic controls). hRTDC were identified using monoclonal antibody labelling and analysis by flow cytometry. Results hRTDC stained HLA‐DR+ (negative for markers of other cell lineages) were predominantly myeloid and comprised ∼0.5% of viable sputum cells. Sputum cells were potent stimulators of allogeneic CD4+ naïve T cells and enrichment/depletion experiments correlated stimulatory potency with DC numbers. Sputum contained cells that exhibited typical dendritic morphology when analysed by electron microscopy. Myeloid hRTDC were endocytically active, but uptake of FITC‐dextran was enhanced in cells from asthmatics (P<0.001). Despite their increased endocytic capacity, asthmatic myeloid hRTDC appeared mature and expressed increased levels of maturation markers (P<0.05–P<0.001), CD1c, CD1d and langerin (P<0.05). CD1c expression by asthmatic myeloid hRTDC was enhanced upon in vivo allergen challenge (three to ninefold within 24 h; P<0.05). CD11c−CD123high hRTDC were only detected in asthmatic sputum and were increased in number following allergen challenge. Conclusion Despite limited cell numbers, it proved possible to analyse human RTDC in induced sputum, providing evidence that increased antigen uptake and enhanced CD1 presentation by activated hRTDC may contribute to allergic airway disease. CD1 presentation by hRTDC in atopic asthma may therefore constitute a novel target for future intervention strategies. 相似文献
34.
Effects of Ethanol Exposure during the Third Trimester Equivalent on Neuron Number in Rat Hippocampus and Dentate Gyrus 总被引:5,自引:0,他引:5
James R. West PhD Kristin M. Hamre BA Martin D. Cassell PhD 《Alcoholism, clinical and experimental research》1986,10(2):190-197
An artificial rearing procedure was used to expose neonatal rats to a formula containing 3.74% ethanol during postnatal days 4 through 10. This treatment produced a mean blood ethanol concentration of 379.8 +/- 17.3 mg/dl. When the pups were killed on the afternoon of postnatal day 10, brain weight to body weight ratio in the ethanol-exposed rats was reduced 22.4% and 21.5% compared to suckle and pair-fed controls, respectively. Ethanol exposure also resulted in a 16% reduction of neurons in hippocampal field CA4, compared to controls, but did not produce deficits in fields CA1 or CA3. There was also a 10% increase in the number of neurons (a population of cells in the midst of a proliferative phase at the time of the exposure) in the granule cell layer of the dentate gyrus. The ethanol exposure did not affect cell size in any of the four neuron populations measured. These results suggest, that within the dose and timing parameters examined, ethanol exposure during the third trimester equivalent appears to be preferentially harmful to specific populations of developing neurons. 相似文献
35.
36.
Mark G Stokes Christopher D Chambers Ian C Gould Therese English Elizabeth McNaught Odette McDonald Jason B Mattingley 《Clinical neurophysiology》2007,118(7):1617-1625
OBJECTIVE: To examine the relationship between coil-cortex distance and effective cortical stimulation using transcranial magnetic stimulation (TMS) in the left and right motor cortex. We also compare the effect of coil-cortex distance using 50 and 70 mm figure-eight stimulating coils. METHODS: Coil-cortex distance was manipulated within each participant using 5 and 10 mm acrylic separators placed between the coil and scalp surface. The effect of cortical stimulation was indexed by resting motor threshold (MT). RESULTS: Increasing distance between the coil and underlying cortex was associated with a steep linear increase in MT. For each additional millimetre separating the stimulating coil from the scalp surface, an additional approximately 2.8% of absolute stimulator output (approximately 0.062 T) was required to reach MT. The gradient of the observed distance effect did not differ between hemispheres, and no differences were observed between the 50 and 70 mm TMS coils. CONCLUSIONS: Coil-cortex distance directly influences the magnitude of cortical stimulation in TMS. The relationship between TMS efficacy and coil-cortex distance is well characterised by a linear function, providing a simple and effective method for scaling stimulator output to a distance adjusted MT. SIGNIFICANCE: MT measured at the scalp-surface is dependent on the underlying scalp-cortex distance, and therefore does not provide an accurate index of cortical excitability. Distance-adjusted MT provides a more accurate index of cortical excitability, and improves the safety and efficacy of MT-calibrated TMS. 相似文献
37.
38.
Rufus S. HoweCPT AN BSE BSN RN-C Claudia ChrlstmanCPT AN MS BA BSN RN-C 《Journal of the American Academy of Nurse Practitioners》1991,3(1):35-41
Noninsulin dependent diabetes (type II diabetes) is a chronic disease characterized by hyperglycemia. Clients can generally be controlled by diet and exercise or a combination of diet, exercise, and oral hypoglycemic agents. When this therapy is not effective in controlling the hyperglycemia, the health care provider must choose to initiate insulin therapy. Outpatient initiation of insulin is an alternative to hospitalization in the type II diabetic client. Clinical guidelines for the initiation of insulin on an outpatient basis and management of the diabetic client are presented. 相似文献
39.
The current study evaluated psychosocial variables that may contribute to the experience of headache in college adults. One hundred ninety-nine participants, 103 women and 96 men, completed head pain logs for 4 weeks after completing measures assessing psychosocial variables. Multiple regression analyses indicated that level of emotional functioning, perception of stress, and gender were predictive of future headache frequency, intensity, and duration. Family history and health habits did not predict headache activity. These findings are consistent with research investigating psychosocial variables and headache activity. 相似文献
40.
Karen A Luker PhD BNurs RGN RHV NDNCert Kinta Beaver BA RGN DPSN Samuel J Leinster BSc MD FRCS R Glynn Owens BTech DipPsych DPhil AFBPsS Lesley F Degner PhD RN Jeffrey A Sloan PhD BSc 《Journal of advanced nursing》1995,22(1):134-141
Nurses can play a key role in patient education, including providing patients with useful and approrate information Rather than focusing on the process of education or information giving by nurses, this study places emphasis on the content of that information by taking the patients'perspective and asking the patients themselves what particular types of information are perceived as important at a specific point in time The aim of the study was to explore what particular types of information were important to women newly diagnosed with breast cancer, to enable nurses and other health care professionals to utilize their time as effectively as possible and provide a high-quality service to individuals in their care Women with breast cancer (a mean of 2 5 weeks from diagnosis) were interviewed and asked to compare items of information The items of information were presented m pairs and the women stated a preference for one item in that pan- Thirty-six pairs were presented in total The analysis involved the use of a Thurstone scaling model, which allowed rank ordermgs, or profiles of information needs, to be developed, reflecting the perceived importance of each item Information about the likelihood of cure, the spread of the disease and treatment options were perceived as the most important items of information at the tune of diagnosis Other information needs, in order of descending priority, included information about the risk to family, side-effects 相似文献