全文获取类型
收费全文 | 3107篇 |
免费 | 167篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 26篇 |
儿科学 | 36篇 |
妇产科学 | 33篇 |
基础医学 | 500篇 |
口腔科学 | 40篇 |
临床医学 | 217篇 |
内科学 | 1048篇 |
皮肤病学 | 29篇 |
神经病学 | 222篇 |
特种医学 | 161篇 |
外科学 | 341篇 |
综合类 | 24篇 |
预防医学 | 88篇 |
眼科学 | 48篇 |
药学 | 152篇 |
中国医学 | 2篇 |
肿瘤学 | 314篇 |
出版年
2023年 | 17篇 |
2022年 | 42篇 |
2021年 | 80篇 |
2020年 | 47篇 |
2019年 | 58篇 |
2018年 | 78篇 |
2017年 | 50篇 |
2016年 | 80篇 |
2015年 | 74篇 |
2014年 | 98篇 |
2013年 | 115篇 |
2012年 | 162篇 |
2011年 | 188篇 |
2010年 | 90篇 |
2009年 | 91篇 |
2008年 | 159篇 |
2007年 | 169篇 |
2006年 | 131篇 |
2005年 | 128篇 |
2004年 | 144篇 |
2003年 | 160篇 |
2002年 | 188篇 |
2001年 | 96篇 |
2000年 | 81篇 |
1999年 | 109篇 |
1998年 | 44篇 |
1997年 | 35篇 |
1996年 | 29篇 |
1995年 | 18篇 |
1994年 | 22篇 |
1993年 | 12篇 |
1992年 | 45篇 |
1991年 | 35篇 |
1990年 | 43篇 |
1989年 | 64篇 |
1988年 | 33篇 |
1987年 | 41篇 |
1986年 | 32篇 |
1985年 | 24篇 |
1984年 | 28篇 |
1983年 | 20篇 |
1981年 | 9篇 |
1980年 | 9篇 |
1979年 | 14篇 |
1978年 | 13篇 |
1977年 | 9篇 |
1974年 | 7篇 |
1973年 | 6篇 |
1970年 | 7篇 |
1968年 | 6篇 |
排序方式: 共有3281条查询结果,搜索用时 15 毫秒
1.
Kensaku Maeda Kenichi Yasunari Eisuke F Sato Junichi Yoshikawa Masayasu Inoue 《Hypertension research》2003,26(12):999-1006
The involvement of oxidative stress in polymorphonuclear leukocytes (PMN) in the pathogenesis of hypertension remains to be elucidated. We analyzed the generation of reactive oxygen species (ROS) by the circulating and peritoneally infiltrating PMN from spontaneously hypertensive rats (SHR) and Wistar Kyoto rats (WKY). Flow cytometric analysis revealed that ROS generation by PMN from SHR was higher than that from WKY before (at 6 weeks of age) and after (at 16 weeks of age) the onset of hypertension. In vivo, ROS generation by PMN from SHR, but not that by PMN from WKY, was significantly suppressed by 10-week treatment with 50 mg/kg/day carvedilol, and this treatment did not affect blood pressure. Western blotting analysis revealed that protein kinase C alpha (PKCalpha), but not PKCbetaI or betaII, was activated more strongly in PMN from SHR than in PMN from WKY. Furthermore, expression of p47phox of nicotinamide adenine dinucleotide phosphate oxidase, but not of p67phox, in PMN from SHR was higher than that in PMN from WKY. These results suggest that ROS generation by PMN is principally enhanced in SHR through activation of PKCalpha and p47phox. 相似文献
2.
3.
Michiko Oka Y. Itoh Shigeru Tatsumi F.-H. Ma Yojiro Ukai Yoshiaki Yoshikuni Kiyoshi Kimura 《Naunyn-Schmiedeberg's archives of pharmacology》1997,356(2):189-196
The effect of (+)-5-oxo-D-prolinepiperidinamide monohydrate (NS-105), a novel cognition enhancer, on adenylate cyclase activity
was investigated in cultured neurons of the mouse cerebral cortex. NS-105 (10–7 and 10–6 M) inhibited forskolin-stimulated cyclic AMP formation, an action that was dependent on pertussis toxin-sensitive G proteins.
Conversely, in pertussis toxin-pretreated neurons, NS-105 (10–7 –10–5 M) significantly enhanced the forskolin-stimulated cyclic AMP formation, and this action was completely reversed by cholera
toxin. A metabotropic glutamate receptor agonist (1S, 3R)-1-aminocyclopentane-1, 3-dicarboxylic acid (1S, 3R-ACPD) produced
similar bi-directional actions on the cyclic AMP formation. Both of these inhibitory and facilitatory actions of NS-105 and
1S, 3R-ACPD were blocked by L(+)-2-amino-3-phosphopropinoic acid (L-AP3). NS-105 (10–6 M) and 1S, 3R-ACPD (10–4 M) significantly enhanced isoproterenol- and adenosine-stimulated cyclic AMP formation. The enhancement of such Gs-coupled
receptor agonists-stimulated cyclic AMP formation was also produced by quisqualate but not by L(+)-2-amino-4-phosphonobutanoate
(L-AP4). The phosphoinositides hydrolysis was enhanced by 1S, 3R-ACPD (10–4 M) but not by NS-105 (10–6 M), however, 1S, 3R-ACPD-induced increase in phosphoinositides turnover was attenuated by NS-105. These findings suggest
that NS-105 stimulates metabotropic glutamate receptor subclasses that are coupled both negatively and positively to adenylate
cyclase, but it acts as an antagonist at the receptor subclasses that are linked to phosphoinositides hydrolysis.
Received: 3 February 1997 / Accepted: 25 April 1997 相似文献
4.
5.
6.
7.
An instrument was developed to detect the shift in scattering of laser light that occurs when particles in suspension move in a chamber with an electrical load. The instrument measures the zeta potential of particles. We applied the instrument to study human blood cells. Platelet-rich plasma was used because of the stability of the suspension, without the sedimentation or autoaggregation that is often seen with red or white blood cells. The reproducibility of the measurements was satisfactory when there were enough platelets in the suspension. Platelets from healthy controls (n = 136) had a potential of -14.20 +/- 1.64 mV at the detection angle of 17.1 degrees. Platelets from patients with essential thrombocytosis (n = 16) or polycythemia vera (n = 8) had higher potentials than the healthy controls. 相似文献
8.
Yasuaki Antoku Eisuke Hanada Kouhei Akazawa Yuko Kenjo Yoshiaki Nose 《Journal of medical systems》1997,21(4):211-218
SOHO (Small Office/Home Office) has recently become popular, as it makes working at home possible. Computers or Local Area Networks(LAN) connected to the office network from home are necessary for the implementation of this concept. Kyushu University has begun a service connecting home computers to the campus LAN for researchers, staff and students of the Faculty of Medicine. We have two different telephone connection methods. One connects the campus LAN and the home computer LAN using routers through the Integrated Services Digital Network (ISDN). The other connects computers at home to the workstation in the university, using modems and the PPP (Point to Point Protocol) through a public telephone analog line. This paper outlines our university SOHO connection system and discusses the merits and demerits of using telephone line connections. 相似文献
9.
A case of Raeder's syndrome caused by metastatic malignant lymphoma was reported. The patient was 67-year-old male. He had complained of diplopia, ptosis and frontal headache at the left side. Neurological examinations revealed left incomplete Horner's syndrome (miosis and ptosis, but normal facial sweating) and left abducens palsy, which was considered to be Raeder's syndrome Group 1 (Boniuk and Schlazinger's classification). CT scan, MRI and angiography demonstrated a mass lesion in the left cavernous sinus extending to the sphenoparietal sinus, and a mass lesion in the anterior part of the superior sagittal sinus. During his hospitalization, enlargement of the left cervical lymph nodes was noticed. "Malignant lymphoma (non-Hodgkin)" was diagnosed on the basis of biopsy. Group 1 of Raeder's syndrome is rare, but it is important to define the site of lesion, which is located around the paratrigeminal region at the middle cranial fossa. Because these lesions are very small and metastatic in many cases, various neuroradiological investigations, especially MRI, are necessary for early diagnosis and early treatment. 相似文献
10.
FGF signaling segregates biliary cell-lineage from chick hepatoblasts cooperatively with BMP4 and ECM components in vitro. 总被引:2,自引:0,他引:2
Masaaki Yanai Norifumi Tatsumi Noboru Hasunuma Kenjiro Katsu Fumio Endo Yuji Yokouchi 《Developmental dynamics》2008,237(5):1268-1283
Intrahepatic bile ducts (IHBDs) are indispensable for transporting bile secreted from hepatocytes to the hepatic duct. The biliary epithelial cells (BECs) of the IHBD arise from bipotent hepatoblasts around the portal vein, suggesting the portal mesenchyme is essential for their development. However, except for Notch or Activin/TGF-beta signaling molecules, it is not known which molecules regulate IHBD development. Here, we found that FGF receptors and BMP4 are specifically expressed in the developing IHBD and the hepatic mesenchyme, respectively. Using a mesenchyme-free culture of liver bud, we showed that bFGF and FGF7 induce the hepatoblasts to differentiate into BECs, and that BMP4 enhances bFGF-induced BEC differentiation. The extracellular matrix (ECM) components in the hepatic mesenchyme induced BEC differentiation. Forced expression of a constitutively active form of the FGF receptor partially induced BEC differentiation markers in vivo. These data strongly suggest that bFGF and FGF7 promote BEC differentiation cooperatively with BMP4 and ECMs in vivo. 相似文献