全文获取类型
收费全文 | 34171篇 |
免费 | 1936篇 |
国内免费 | 169篇 |
专业分类
耳鼻咽喉 | 307篇 |
儿科学 | 505篇 |
妇产科学 | 371篇 |
基础医学 | 4612篇 |
口腔科学 | 1040篇 |
临床医学 | 2249篇 |
内科学 | 8193篇 |
皮肤病学 | 894篇 |
神经病学 | 2352篇 |
特种医学 | 1366篇 |
外科学 | 5795篇 |
综合类 | 166篇 |
一般理论 | 1篇 |
预防医学 | 1138篇 |
眼科学 | 701篇 |
药学 | 2724篇 |
中国医学 | 91篇 |
肿瘤学 | 3771篇 |
出版年
2023年 | 161篇 |
2022年 | 345篇 |
2021年 | 586篇 |
2020年 | 359篇 |
2019年 | 438篇 |
2018年 | 566篇 |
2017年 | 516篇 |
2016年 | 550篇 |
2015年 | 601篇 |
2014年 | 777篇 |
2013年 | 1001篇 |
2012年 | 1518篇 |
2011年 | 1681篇 |
2010年 | 946篇 |
2009年 | 873篇 |
2008年 | 1474篇 |
2007年 | 1503篇 |
2006年 | 1521篇 |
2005年 | 1614篇 |
2004年 | 1507篇 |
2003年 | 1488篇 |
2002年 | 1424篇 |
2001年 | 1307篇 |
2000年 | 1348篇 |
1999年 | 1211篇 |
1998年 | 431篇 |
1997年 | 360篇 |
1996年 | 321篇 |
1995年 | 306篇 |
1994年 | 275篇 |
1993年 | 257篇 |
1992年 | 828篇 |
1991年 | 732篇 |
1990年 | 747篇 |
1989年 | 707篇 |
1988年 | 719篇 |
1987年 | 626篇 |
1986年 | 620篇 |
1985年 | 601篇 |
1984年 | 396篇 |
1983年 | 325篇 |
1982年 | 155篇 |
1979年 | 320篇 |
1978年 | 209篇 |
1977年 | 151篇 |
1975年 | 149篇 |
1974年 | 214篇 |
1973年 | 152篇 |
1972年 | 166篇 |
1971年 | 148篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
81.
Osteopontin expression in osteoblasts and osteocytes during bone formation under mechanical stress in the calvarial suture in vivo. 总被引:3,自引:0,他引:3
82.
T Ohashi F Yamamoto H Yamamoto H Ichikawa T Shibata Y Shimada T Ishikawa K Kagisaki Y Kumada Y Kawashima 《[Zasshi] [Journal]. Nihon Kyōbu Geka Gakkai》1992,40(11):1998-2004
The effects of potassium in reperfusion solution (RS) and the influence of sodium on this effect were studied. Experimental time course was as followed: 20 min working perfusion, 3 min cardioplegic infusion with St. Thomas Cardioplegic Solution followed by global ischemia for 33 or 35 min at 37.5 degrees C, 15 min early Langendorff reperfusion with several different potassium concentration modified with Krebs Henseleit Bicarbonate Buffer (KHBB) containing 145 mM and 110 mM sodium and 5 min late reperfusion with KHBB, followed by 20 min working perfusion. Potassium in RS possessed bell shaped dose response nature with optimal concentration of 10 mM in the condition of 145 mM sodium but 6 m in the condition of 110 mM in terms of percent recovery of aortic flow. Although higher potassium reperfusion produced less Creatine Kinase leakage. 相似文献
83.
Seishiro Hirano Takako Asami Naomi Kodama Kazuo T. Suzuki 《Archives of toxicology》1994,68(7):444-449
In a preceding study, we reported that the numbers of macrophages and polymorphonuclear leukocytes (PMN) were increased in
bronchoalveolar lavage fluid (BALF) following the intratracheal instillation of nickel sulfate (NiSO4) in rats. In the present study, BALF chemotactic activities for both macrophages and PMN were measured to investigate if
the increases of these inflammatory cells in BALF depend on increases in chemotactic activities in epithelial lining fluid
(ELF) of the lung. Both the number of PMN and the PMN chemotactic activity peaked at 2 days post-instillation and they were
significantly correlated. However, the PMN chemotactic activity was inversely correlated with concentration of leukotriene
B4 (LTB4), a well-known chemotaxin. Although PMN were not observed in control BALF, LTB4 concentration in the control ELF (ca. 5×10–7 M) was estimated to have a potential to attract PMN chemotactically through a membrane in in vitro migration assay. These
results suggest that the presence of LTB4 in ELF itself does not trigger transpulmonary PMN infiltration. The rat BALF were fractionated by high performance liquid
chromatography (HPLC), and PMN chemotactic activity of each fraction was measured. The elution profiles of PMN chemotactic
activity showed that there were at least two different chemotaxins in BALF obtained from the NiSO4-exposed rats. Macrophage chemotactic activity in BALF also peaked at 2 days post-instillation. However, the number of macrophages
was not significantly correlated with the chemotactic activity for macrophage in BALF. The HPLC study showed that the macrophage
chemotactic substance in the BALF obtained from NiSO4-exposed rats was different from complement fragment (C5a) and its MW was estimated to be 10 – 12 kD.
Received: 1 December 1993/Accepted: 16 March 1994 相似文献
84.
85.
K Hirano U M Domar H Yamamoto E E Brehmer-Andersson B E Wahren T I Stigbrand 《Cancer research》1987,47(10):2543-2546
The three human isozymes of alkaline phosphatases were quantitatively determined in normal testis and seminoma tissues. The highly selective assays were based on isozyme specific monoclonal antibodies. In the normal testis approximately 90% of the catalytic activity originates from the tissue unspecific alkaline phosphatase, and the remaining activity was due to trace expression of both intestinal (approximately 5%) and placental alkaline phosphatase (PLAP) or PLAP-like isozyme (approximately 5%). In homogenates of seminoma tissues, highly increased levels of all three isozymes were identified. Both the tissue unspecific alkaline phosphatase and PLAP-like enzymes displayed relative increases of 10- to 100-fold and intestinal alkaline phosphatase 2- to 10-fold compared with normal testis. This finding indicates that the entire genome coding for alkaline phosphatases may be activated in seminomas. The PLAP-like enzyme from seminoma cells comprises a heterogenous population of molecules demonstrating partial heat sensitivity and microheterogeneity upon starch gel electrophoresis in contrast to the pregnancy related PLAP. These findings have implications for the different PLAP assays used in the clinical monitoring of seminoma patients. 相似文献
86.
87.
88.
89.
90.
Satoshi Yamamoto MD ; Yosinobu Sato MD ; Toru Abo MD ; Katsuyosi Hatakeyama MD 《Wound repair and regeneration》2002,10(4):241-244
Recently, we found CD3-CD4(bright) cells with comparative specificity for normal rat liver. In the current study, we investigated the type and form of both CD3-CD4(bright) cells and CD3-CD4(dull) cells in the rat liver. The surface phenotype of hepatic mononuclear cells in Lewis rats was identified by using monoclonal antibodies including anti-CD4, anti-CD3, and antimacrophage in conjunction with two- or three-color immunofluorescence analysis. CD3-CD4(bright) cells and CD3-CD4(dull) cells were examined morphologically using May-Giemsa staining and scanning electron microscopy. The distribution of CD3-CD4(bright) cells and CD3-CD4(dull) cells 48 hours after intravenous administration of liposome-encapsulated dichloromethylene diphosphate was also investigated. In comparison to CD3-CD4(dull) cells, CD3-CD4(bright) cells were slightly larger macrophages with abundant cytoplasmic granules, being present with comparative specificity for normal rat liver and showing negligible effects by intravenous liposome-encapsulated dichloromethylene diphosphate administration. These data suggest that in normal young rat liver these CD3-CD4(dull) and CD3-CD4(bright) cells may be dendritic cells and Kupffer cells that shift from the liver to the spleen or vice versa. These cells may also be able to locally proliferate in liver or spleen due to changes in the developing liver. 相似文献