全文获取类型
收费全文 | 4327篇 |
免费 | 349篇 |
国内免费 | 13篇 |
专业分类
耳鼻咽喉 | 10篇 |
儿科学 | 193篇 |
妇产科学 | 46篇 |
基础医学 | 409篇 |
口腔科学 | 174篇 |
临床医学 | 639篇 |
内科学 | 747篇 |
皮肤病学 | 316篇 |
神经病学 | 421篇 |
特种医学 | 383篇 |
外科学 | 442篇 |
综合类 | 120篇 |
一般理论 | 3篇 |
预防医学 | 265篇 |
眼科学 | 23篇 |
药学 | 313篇 |
肿瘤学 | 185篇 |
出版年
2023年 | 20篇 |
2022年 | 22篇 |
2021年 | 58篇 |
2020年 | 56篇 |
2019年 | 70篇 |
2018年 | 85篇 |
2017年 | 73篇 |
2016年 | 71篇 |
2015年 | 76篇 |
2014年 | 96篇 |
2013年 | 140篇 |
2012年 | 170篇 |
2011年 | 208篇 |
2010年 | 174篇 |
2009年 | 119篇 |
2008年 | 180篇 |
2007年 | 187篇 |
2006年 | 176篇 |
2005年 | 160篇 |
2004年 | 152篇 |
2003年 | 145篇 |
2002年 | 148篇 |
2001年 | 125篇 |
2000年 | 119篇 |
1999年 | 132篇 |
1998年 | 132篇 |
1997年 | 99篇 |
1996年 | 100篇 |
1995年 | 81篇 |
1994年 | 73篇 |
1993年 | 85篇 |
1992年 | 82篇 |
1991年 | 76篇 |
1990年 | 74篇 |
1989年 | 101篇 |
1988年 | 85篇 |
1987年 | 80篇 |
1986年 | 74篇 |
1985年 | 83篇 |
1984年 | 61篇 |
1983年 | 40篇 |
1982年 | 36篇 |
1981年 | 33篇 |
1980年 | 47篇 |
1979年 | 25篇 |
1978年 | 32篇 |
1977年 | 35篇 |
1976年 | 34篇 |
1975年 | 29篇 |
1973年 | 11篇 |
排序方式: 共有4689条查询结果,搜索用时 15 毫秒
11.
Expression of functional postjunctional alpha 2-adrenoceptors in rabbit isolated distal saphenous artery--a permissive role for angiotensin II? 总被引:9,自引:9,他引:0
In the rabbit isolated distal saphenous artery, the population of postjunctional adrenoceptors is of the alpha 1 variety under normal in vitro experimental conditions, based on the potency order of selective agonists and on the effects of the antagonists prazosin and rauwolscine against responses to UK-14304. Angiotensin II (A II, 0.05 microM) however, without affecting resting baseline tension, markedly enhanced responses to UK-14304, particularly at low concentrations. This previously unseen component of the response to UK-14304 was resistant to prazosin (0.1 microM) but susceptible to rauwolscine (1 microM). A II would therefore appear to have a permissive role for the expression of a quiescent population of postjunctional alpha 2-adrenoceptors in the rabbit distal saphenous artery. 相似文献
12.
Immediate and delayed cord clamping in infants born between 24 and 32 weeks: a pilot randomized controlled trial. 总被引:1,自引:0,他引:1
Judith S Mercer Margaret M McGrath Angelita Hensman Helayne Silver William Oh 《Journal of perinatology》2003,23(6):466-472
OBJECTIVE: This pilot study's aim was to establish feasibility of a protocol for delayed cord clamping (DCC) versus immediate cord clamping (ICC) at preterm birth and to examine its effects on initial blood pressure and other outcomes. STUDY DESIGN: A randomized controlled trial recruited 32 infants between 24 and 32 weeks. Immediately before delivery, mothers were randomized to ICC (cord clamped at 5 to 10 seconds) or DCC (30- to 45-second delay in cord clamping) groups. RESULTS: Intention-to-treat analyses revealed that the DCC group were more likely to have higher initial mean blood pressures (adjusted OR 3.4) and less likely to be discharged on oxygen (adjusted OR 8.6). DCC group infants had higher initial glucose levels (ICC=36 mg/dl, DCC=73.1 mg/dl; p=0.02). CONCLUSION: The research design is feasible. The immediate benefit of improved blood pressure was confirmed and other findings deserve consideration for further study. 相似文献
13.
14.
15.
荧光原位杂交技术分析人结肠菌群方法研究 总被引:2,自引:0,他引:2
建立荧光原位杂交技术分析人体内结肠菌群的方法。取受试者新鲜粪便 ,选用 5种特异性的 16SrRNA寡核苷酸探针 ,检测粪便样本收集后的保存时间、温度 ,离心条件及样本固定液存放时间对杂交计数结果的影响。结果建立最佳实验条件为 :粪便样本收集后应尽快在 4℃下保存 ,放置时间不要超过 12小时即作处理 ;样本的适宜离心条件为 70 0g 2分钟 ;样本用多聚甲醛固定后在 - 80℃下存放时间不要超过 5个月。该方法具有较好的稳定性 ,可以有效地检出个体之间结肠菌群的差异。 相似文献
16.
17.
18.
19.
While the season-of-birth effect is one of the most consistent epidemiological features of schizophrenia, there is a lack
of consistency with respect to the interaction between season of birth and family history of schizophrenia. Apart from family
history, measures related to consanguinity can be used as proxy markers of genomic heterogeneity. Thus, these measures may
provide an alternate, indirect index of genetic susceptibility. We had the opportunity to explore the interaction between
season of birth and measure of consanguinity in well-described genetic isolates in Daghestan, some of which are known for
their relatively high prevalence of schizophrenia. Our previous population-genetic study showed Daghestan has an extremely
high genetic diversity between the ethnic populations and a low genetic diversity within them. The isolates selected for this
study include some with more than 200 and some with less than 100 generations of demographical history since their founding.
Based on pedigrees of multiply-affected families, we found that among individuals with schizophrenia, the measure of consanguinity
was significantly higher in the parents of those born in winter/spring compared to those born in summer/autumn. Furthermore,
compared to summer/autumn born, winter/spring born individuals with schizophrenia had an earlier age-of-onset, and more prominent
auditory hallucinations. Our results suggest that the offspring of consanguineous marriages, and thus those with reduced allelic
heterogeneity, may be more susceptible to the environmental factor(s) underpinning the season-of-the effect in schizophrenia. 相似文献
20.