全文获取类型
收费全文 | 9839篇 |
免费 | 1212篇 |
国内免费 | 11篇 |
专业分类
耳鼻咽喉 | 125篇 |
儿科学 | 364篇 |
妇产科学 | 211篇 |
基础医学 | 1301篇 |
口腔科学 | 271篇 |
临床医学 | 1048篇 |
内科学 | 2613篇 |
皮肤病学 | 224篇 |
神经病学 | 605篇 |
特种医学 | 684篇 |
外科学 | 936篇 |
综合类 | 326篇 |
一般理论 | 4篇 |
预防医学 | 955篇 |
眼科学 | 117篇 |
药学 | 789篇 |
1篇 | |
中国医学 | 12篇 |
肿瘤学 | 476篇 |
出版年
2021年 | 107篇 |
2020年 | 91篇 |
2019年 | 141篇 |
2018年 | 146篇 |
2017年 | 137篇 |
2016年 | 156篇 |
2015年 | 180篇 |
2014年 | 236篇 |
2013年 | 301篇 |
2012年 | 383篇 |
2011年 | 453篇 |
2010年 | 253篇 |
2009年 | 256篇 |
2008年 | 337篇 |
2007年 | 390篇 |
2006年 | 412篇 |
2005年 | 410篇 |
2004年 | 364篇 |
2003年 | 330篇 |
2002年 | 318篇 |
2001年 | 318篇 |
2000年 | 301篇 |
1999年 | 251篇 |
1998年 | 193篇 |
1997年 | 161篇 |
1996年 | 164篇 |
1995年 | 171篇 |
1994年 | 126篇 |
1993年 | 151篇 |
1992年 | 202篇 |
1991年 | 209篇 |
1990年 | 196篇 |
1989年 | 226篇 |
1988年 | 214篇 |
1987年 | 216篇 |
1986年 | 239篇 |
1985年 | 238篇 |
1984年 | 176篇 |
1983年 | 130篇 |
1982年 | 120篇 |
1981年 | 113篇 |
1980年 | 111篇 |
1979年 | 127篇 |
1978年 | 98篇 |
1977年 | 98篇 |
1976年 | 92篇 |
1975年 | 92篇 |
1974年 | 83篇 |
1973年 | 90篇 |
1971年 | 66篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
F. A. Ashley B. Gibson B. Daly S. Lygo Baker J. T. Newton 《European journal of dental education》2006,10(1):10-19
The aim of this study was to explore undergraduate and postgraduate dental students' understanding of a good learning experience by using 'reflection on learning' as described by Schon. Four groups of Year 4 BDS students and one group of postgraduate students in dental public health took part in a series of focus group discussions. The responses were grouped into four broad themes (a) active, practical and positive learning; (b) interactive/together learning; (c) personal learning; (d) theory into practice. Six educational models of good learning proposed by the students are described. 相似文献
52.
The inhibitory action of the major constituent of Genista tridentata L. (Papilionaceae), 4',5,7-trihydroxyisoflavone (genistein), on contractions induced by agonists and electrical field stimulation of smooth muscle was analysed. Genistein inhibited twitches evoked by electrical-stimulation of strips of guinea-pig ileum with an IC50 value of 34 microM. Genistein (34 microM) inhibited contractions of the guinea-pig ileum by several agonists in a non-selective, antispasmodic action and had no effect on inhibition of 3H-ACh release from ileal myenteric plexus. Genistein (34 microM) produces an increase in cAMP levels of guinea-pig ileum which resulted in a smooth muscle relaxation which leads us to think that there must be a blockade of its phosphodiesterase. 相似文献
53.
目的:本研究旨在探讨多巴酚丁胺对缺血性心肌病(ICM)患者左心室(LV)充盈功能的影响,并确定峰值负荷时限制性充盈型(RFP)是否具有预后预测价值。背景:ICM患者峰值负荷时RFP的预后价值尚属未知。方法:在静息和负荷情况下,采用多普勒超声心动检查研究了69例ICM患者;RFP定义为跨二尖瓣E/A比≥1.0、等容舒张时间(IVRT)〈80ms及E波减速时间(EDT)〈120ms。结果:69例患者中有42例静息时出现RFP,其中有24例患者负荷情况下转变为非RFP(EA),18例患者RFP持续存在(EE);69例患者中27例静息和峰值负荷时均无RFP(AA)。 相似文献
54.
55.
Abstract Background: Aged Care Assessment Teams (ACATs) have been established throughout Australia during the past seven years. Early studies of their effect have concentrated on their impact on the rate of institutionalisation of disabled elderly, the clinical characteristics of referred cases and the relationship between disability and recommended care plan. Aims: The aim of this study was to explore the relationship between age, clinical features and social characteristics of AC AT subjects with outcomes at 12 months after assessment. Methods: The examination of an arbitrary sample of persons referred to ACATs over a year by one generalist geriatrician with follow-up of all cases by the three ACATs associated with the study was carried out. All analyses were performed on raw data presented as categorical variables in the form of contingency tables. Results: The sample included 324 subjects who suffered from 2030 clinical problems with a mean of 6.5 per person aged 75 or over and 5.5 for those under 75. Cardiovascular and neurological disease were the commonest source of problems. Study of accommodation outcome at 12 months, for those subjects who survived this period revealed that, in the older group, over 60% of subjects with neurological disease were resident in nursing homes while the majority of all other groups remained in the community, as did two-thirds of those aged under 75. Admission to a nursing home was independent of social support for older subjects with neurological disease, but it played a significant role in those with cardiopulmonary or musculoskeletal disease. Conclusions: The study demonstrates that for one-year survivors there is an increased likelihood of admission to a nursing home of people aged 75 or over with neurological disease, while those under 75 were more likely to remain at home. The association was independent of whether spouse, family or friends were living with the subject. (Aust NZ J Med 1994; 24: 378–385.) 相似文献
56.
The effectiveness of intranasal corticosteroids in combined allergic rhinitis and asthma syndrome 总被引:2,自引:0,他引:2
Background Allergic rhinitis (AR) and asthma often coexist and may represent two manifestations of the same disease recently named combined AR and asthma syndrome (CARAS). Aim To review the common pathophysiology of combined AR and asthma and to investigate the efficacy of intranasal corticosteroids (INCS). Methods Medline was used to identify articles relevant to mechanisms. A Cochrane systematic review was performed to assess the efficacy of INCS in CARAS. Results There is cross‐talk, evidence of a common inflammatory response in both sites, linked by a systemic component. The efficacy of anti‐inflammatory INCS on asthma outcomes was assessed in a systematic review of 12 randomized controlled trials involving 425 subjects. After INCS there were non‐significant trends for improvement in asthma symptom score (standardized mean difference (SMD) of 0.61; P=0.07), forced expiratory volume in 1 s (SMD of 0.31; P=0.08), and morning peak expiratory flow (weighted mean difference of 36.51; P=0.06). There was no impact on methacholine airways responsiveness (SMD of ?0.20; P=0.4). The review identified two promising new treatment options in united airway disease such as INCS as monotherapy in rhinitis and mild asthma, and a combined intranasal and intrabronchial corticosteroid (IBCS) deposition technique. Conclusion Common mucosal inflammatory responses occur in CARAS. This systematic review shows trends for a benefit of INCS in CARAS, but recognizes that more research is needed. At this stage, the current best practice is to treat asthma conventionally with IBCS with or without β2‐agonist and to add INCS to improve specific rhinitis symptoms. 相似文献
57.
Plasma biochemical and haematological parameters were examined in 4-week-old to 12-week-old game birds. Healthy, uninfected pheasants and partridges had similar levels of total protein, albumin, osmolality, Na+, Cl-, K+, Mg2+ and glucose. Triglyceride, globulin and Ca2+ were significantly higher and PO43- was lower in the partridges. Pheasants carrying a light to moderate infection with Spironucleus had significantly lower total protein, albumin, osmolality, Na+, Cl-, Ca2+ and PO43-. In severely affected pheasants, the osmolality, Na+ and Cl- fell further. Triglyceride and glucose were significantly lower than in healthy birds, and Mg2+ was higher. Similar data were obtained from infected partridges. Red cell parameters rose significantly in pheasants severely affected by spironucleosis, and the percent of heterophils was significantly higher and lymphocytes and basophils lower in their blood smears. The breast and leg muscle wet weight from severely affected pheasants was 22.2 and 37.7% that of uninfected birds, although the water content of the breast muscle was significantly higher. 相似文献
58.
P G Gibson J L Simpson 《The European respiratory journal》2004,23(3):492; author reply 492-492; author reply 493
59.
Anderson RA; Evans LW; Irvine DS; McIntyre MA; Groome NP; Riley SC 《Human reproduction (Oxford, England)》1998,13(12):3319-3325
Follistatin is a binding protein for the activin and inhibin family of
hormones, regulating their biological activity. In the male reproductive
tract, the interaction of these factors is likely to be involved in the
regulation of the proliferation of several cell types. We have investigated
the presence of follistatin and activin A in seminal plasma using specific
immunoassays and have localized follistatin and activin/inhibin subunits in
the adult human testis, prostate and seminal vesicle to establish their
likely sources. High concentrations of immunoreactive follistatin were
present in seminal plasma in normal men (mean 97.9 ng/ml; 1.43 ng/ml in
peripheral plasma) and were similar in men with oligo/azoospermia and
following vasectomy. Follistatin immunoreactivity was localized to both
Leydig and Sertoli cells of the testis, and to epithelial cells of the
prostate gland and seminal vesicle, which are likely to be the predominant
sources of the hormone in seminal plasma. Activin A was also present in
seminal plasma in normal men but was undetectable following vasectomy, thus
deriving from the testis. Consistent with this finding, the betaA-subunit
was immunolocalized in Sertoli and Leydig cells but was not present in
seminal vesicle or prostate gland. The functional significance of the high
concentrations of follistatin secreted into seminal plasma by the prostate
gland and/or seminal vesicle is uncertain, but they may regulate the
biological activity of testis-derived activin A and inhibin B.
相似文献
60.
Prognostic factors in myeloma are not only important for allowing comparisons to be made between therapeutic protocols but they also provide us with an insight into the pathophysiology of the disease and important mechanisms which result in disease progression. Prognostic factors in myeloma relate to the inherent proliferative capacity of the malignant clone, tumor bulk, renal function and other factors which reflect tumor host and host tumor interactions. The highly significant effect of the labelling index (LI) suggests that the clonogenic cell is ontologically very close to the malignant plasma cell on which the labelling index is derived. The explanation for the important role of the β2-microglobulin (β2M) level over and above its reflection of renal function is as yet unclear. 相似文献