全文获取类型
收费全文 | 59569篇 |
免费 | 4850篇 |
国内免费 | 1596篇 |
专业分类
耳鼻咽喉 | 721篇 |
儿科学 | 936篇 |
妇产科学 | 1421篇 |
基础医学 | 9157篇 |
口腔科学 | 1542篇 |
临床医学 | 4883篇 |
内科学 | 11804篇 |
皮肤病学 | 1128篇 |
神经病学 | 4396篇 |
特种医学 | 1870篇 |
外国民族医学 | 6篇 |
外科学 | 8465篇 |
综合类 | 3988篇 |
现状与发展 | 1篇 |
一般理论 | 5篇 |
预防医学 | 3471篇 |
眼科学 | 1530篇 |
药学 | 5184篇 |
中国医学 | 789篇 |
肿瘤学 | 4718篇 |
出版年
2023年 | 211篇 |
2022年 | 299篇 |
2021年 | 642篇 |
2020年 | 415篇 |
2019年 | 738篇 |
2018年 | 1252篇 |
2017年 | 955篇 |
2016年 | 948篇 |
2015年 | 1101篇 |
2014年 | 1470篇 |
2013年 | 1802篇 |
2012年 | 2478篇 |
2011年 | 2435篇 |
2010年 | 1440篇 |
2009年 | 1398篇 |
2008年 | 2239篇 |
2007年 | 2409篇 |
2006年 | 2269篇 |
2005年 | 1926篇 |
2004年 | 1781篇 |
2003年 | 1700篇 |
2002年 | 1665篇 |
2001年 | 4953篇 |
2000年 | 4902篇 |
1999年 | 4181篇 |
1998年 | 1458篇 |
1997年 | 1062篇 |
1996年 | 678篇 |
1995年 | 563篇 |
1994年 | 502篇 |
1993年 | 470篇 |
1992年 | 2100篇 |
1991年 | 1821篇 |
1990年 | 1647篇 |
1989年 | 1585篇 |
1988年 | 1398篇 |
1987年 | 1295篇 |
1986年 | 1133篇 |
1985年 | 966篇 |
1984年 | 635篇 |
1983年 | 505篇 |
1982年 | 275篇 |
1981年 | 209篇 |
1980年 | 155篇 |
1979年 | 310篇 |
1978年 | 95篇 |
1974年 | 91篇 |
1973年 | 119篇 |
1970年 | 96篇 |
1968年 | 92篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
141.
In this paper the immunosuppressive effects of Gui Zhi Tang (a famous Chinese medicine) on the murine immune functions are reported. Varying dosages of Gui Zhi Tang administrated orally, i.p. and i.m. were able to inhibit the amounts of PFC, SRFC and the DTH response induced by BSA and the proliferation response of murine spleen cells to Con A and LPS. Further studies showed that Gui Zhi Tang had the inhibitory effect on Interleukin-2 production of murine spleen cells, which might be one of the mechanisms leading to the immunosuppressive effects of Gui Zhi Tang. 相似文献
142.
143.
144.
145.
N Curcó† X Pagerols† M García† X Tarroch‡ P Vives† 《Journal of the European Academy of Dermatology and Venereology》2006,20(3):331-333
A 40-year-old man presented a painful haemorrhagic plaque on his chest in the same location where a nodular lesion had been presented for many years. After 2 months, the plaque was replaced by a depressed lesion. The lesion diagnosed as an anetoderma was excised and the biopsy showed an atrophic dermatofibroma accompanied by aneurysmatic characteristics. 相似文献
146.
X Z Huang 《中华结核和呼吸杂志》1991,14(4):225-7, 256
Sixteen patients (male: 14, female: 2, 41-72 yrs, mean 57.5 yrs) with OSAS were treated by nCPAP in our hospital since 1987. Respiratory disturbance index ranged from 16.5 to 83.1. The longest apnea duration was 35.0-120.5 seconds before the treatment. Two patients were treated with Sleep Easy III (Respironics Inc.) and others with a home made instruments. nCPAP was set at a pressure of 5 to 10 cm H2O. 12 patients (75%) tolerated the device but 4(25%) did not. Polysomnographic parameters before and after nCPAP therapy were compared. The longest apnea duration was 63.1 +/- 23.5 to 40.9 +/- 27.4 seconds (P less than 0.001) and the lowest saturation oxygen was 55.1 +/- 20.4% to 71.4 +/- 18.6% (P less than 0.05). The sleep structure improved but not significant statistically. One of them used nCPAP at home for more than two. years and showed a good long term effect. We concluded that nCPAP is an effective and safe treatment for OSAS. However, patients may be uncomfortable because of the wearing of the nasal mask during sleep. 相似文献
147.
Inbred mouse strains have different numbers of midbrain dopaminergic neurons; for example, BALB/cJ mice have 20–25% more neurons than CBA/J mice. As the number of cells decrease, for example in Parkinson's disease and in animals with midbrain dopaminergic cell lesions, the activity of their remaining cells increases. The purpose of the present experiment was to determine whether the functional properties of dopaminergic neurons in the ventral tegmental area (nucleus A10) differ in inbred mouse strains which possess different numbers of cells. The firing rate and autoreceptor sensitivity of A10 dopaminergic cells were examined in the in vitro slice preparation in BALB/cJ, C3H/HeJ, CBA/J, and DBA/2J mouse strains. It was observed that the autoreceptors on mouse dopaminergic neurons exhibit pharmacological properties of dopamine autoreceptors; activation of the autoreceptor produced a marked inhibition (50–70%) in cell firing rate by quinpirole (10−8 M), LY-141865 (10−7 M), (+)-3-(3-hydroxyphenyl)-N-n-propyl-piperidine (10−6 M), propyl-norapomorphine (10−5 M) and dopamine (10−4 M), and this inhibition was blocked or reversed by specific dopamine D2 receptor antagonists [(−) sulphide and spiroperidol, 10−6 M]. The baseline firing rates of the A10 cells did not differ among the four inbred strains [range 2.5 ± 0.2 (C3H/HeJ)−3.4 ± 0.3 (CBA/J) spikes/s ±SEM], and there was no significant difference in autoreceptor sensitivity among the mouse strains as assessed either by superfused dopamine (inhibitory dose 50% ≈150 μM), or by superfused quinpirole (inhibitory dose 50% ≈10 nM). These data indicate that differences in A10 cell numbers of 30% do not significantly influence the baseline firing rate or autoreceptor sensitivity of the cells. 相似文献
148.
Steven N Singh X Charlene Tang Bramah N Singh Paul Dorian Domenic J Reda Crystal L Harris Ross D Fletcher Satish C Sharma J Edwin Atwood Alan K Jacobson H Daniel Lewis Becky Lopez Dennis W Raisch Michael D Ezekowitz 《Journal of the American College of Cardiology》2006,48(4):721-730
OBJECTIVES: The purpose of this study was to determine quality of life (QOL) and exercise performance (EP) in patients with persistent atrial fibrillation (AF) converted to sinus rhythm (SR) compared with those remaining in or reverting to AF. BACKGROUND: Restoration of SR in patients with AF improving QOL and EP remains controversial. METHODS: Patients with persistent AF were randomized double-blind to amiodarone, sotalol, or placebo. Those not achieving SR at day 28 were cardioverted and classified into SR or AF groups at 8 weeks (n = 624) and 1 year (n = 556). The QOL (SF-36), symptom checklist (SCL), specific activity scale (SAS), AF severity scale (AFSS), and EP were assessed. RESULTS: Favorable changes were seen in SR patients at 8 weeks in physical functioning (p < 0.001), physical role limitations (p = 0.03), general health (p = 0.002), and vitality (p < 0.001), and at 1 year in general health (p = 0.007) and social functioning (p = 0.02). Changes in the scores for SCL severity (p = 0.01), functional capacity (p = 0.003), and AFSS symptom burden (p < 0.001) at 8 weeks and in SCL severity (p < 0.01) and AF symptom burden (p < 0.001) at 1 year showed significant improvements in SR versus AF. Symptomatic patients were more likely to have improvement. The EP in SR versus AF was greater from baseline to 8 weeks (p = 0.01) and to 1 year (p = 0.02). The EP correlated with physical functioning and functional capacity except in the AF group at 1 year. CONCLUSIONS: In patients with persistent AF, restoration and maintenance of SR was associated with improvements in QOL measures and EP. There was a strong correlation between QOL measures and EP. 相似文献
149.
William P Lafuse Gail R Alvarez Heather M Curry Bruce S Zwilling 《Journal of interferon & cytokine research》2006,26(8):548-561
Mycobacteria-infected macrophages are poor responders to interferon-gamma (IFN-gamma), resulting in decreased expression of IFN-gamma-induced genes. In the present study, we examined the inhibition of IFN-gamma-induced gene expression by Mycobacterium tuberculosis and four different Mycobacterium avium strains in mouse RAW264.7 macrophages. Gamma-irradiated M. tuberculosis inhibited mRNA expression of a panel of six different IFN- gamma-induced genes. All four of the M. avium strains completely inhibited IFN-gamma-induced expression of MHC class II Aalpha and Ebeta mRNA. However, the Mac101 strain, which is serovar 1, inhibited IFN-gamma induction of IFN regulatory factor-1 (IRF-1) and guanylate-binding protein-1 (GBP-1) mRNA to a greater extent than the other M. avium strains, which are serovar 2. In this study, we also show that mycobacteria inhibit gene expression by both toll-like receptor 2 (TLR2)-dependent and independent pathways. The inhibition of IFN-gamma-induced gene expression by M. avium was reduced but not completely blocked in macrophages from TLR2(/) mice. IFN-gamma-induced gene expression was also inhibited by mycobacteria in RAW264.7 cells expressing dominantnegative TLR2 or myeloid differentiation factor 88 (MyD88), further indicating the existence of a pathway independent of TLR2 and MyD88. These data suggest that mycobacteria inhibit IFN-gamma-induced gene expression by multiple pathways involving both TLR2 and non-TLR receptors. 相似文献
150.