全文获取类型
收费全文 | 15205篇 |
免费 | 770篇 |
国内免费 | 125篇 |
专业分类
耳鼻咽喉 | 101篇 |
儿科学 | 319篇 |
妇产科学 | 120篇 |
基础医学 | 1790篇 |
口腔科学 | 232篇 |
临床医学 | 1123篇 |
内科学 | 4285篇 |
皮肤病学 | 243篇 |
神经病学 | 934篇 |
特种医学 | 843篇 |
外科学 | 2633篇 |
综合类 | 52篇 |
预防医学 | 395篇 |
眼科学 | 188篇 |
药学 | 869篇 |
中国医学 | 44篇 |
肿瘤学 | 1929篇 |
出版年
2023年 | 147篇 |
2022年 | 266篇 |
2021年 | 519篇 |
2020年 | 262篇 |
2019年 | 340篇 |
2018年 | 439篇 |
2017年 | 326篇 |
2016年 | 359篇 |
2015年 | 335篇 |
2014年 | 491篇 |
2013年 | 548篇 |
2012年 | 937篇 |
2011年 | 987篇 |
2010年 | 539篇 |
2009年 | 465篇 |
2008年 | 785篇 |
2007年 | 820篇 |
2006年 | 781篇 |
2005年 | 819篇 |
2004年 | 815篇 |
2003年 | 805篇 |
2002年 | 705篇 |
2001年 | 372篇 |
2000年 | 381篇 |
1999年 | 378篇 |
1998年 | 177篇 |
1997年 | 149篇 |
1996年 | 124篇 |
1995年 | 87篇 |
1994年 | 79篇 |
1993年 | 82篇 |
1992年 | 171篇 |
1991年 | 168篇 |
1990年 | 170篇 |
1989年 | 139篇 |
1988年 | 141篇 |
1987年 | 117篇 |
1986年 | 120篇 |
1985年 | 108篇 |
1984年 | 65篇 |
1983年 | 79篇 |
1982年 | 26篇 |
1981年 | 30篇 |
1979年 | 58篇 |
1978年 | 41篇 |
1975年 | 35篇 |
1974年 | 28篇 |
1970年 | 36篇 |
1969年 | 25篇 |
1968年 | 30篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
11.
T. Yoshikawa H. Tohyama H. Enomoto H. Matsumoto Y. Toyama K. Yasuda 《Knee surgery, sports traumatology, arthroscopy》2006,14(9):804-810
The aim of this study was to clarify vascular endothelial growth factor (VEGF) expression and angiogenesis in the patellar tendon (PT) autograft in the early phase after anterior cruciate ligament (ACL) reconstruction using a rabbit model. The right knees of 30 Japanese white rabbits underwent ACL reconstruction using the medial third of the PT complex. We evaluated the grafted tendon at 1, 2, 3, 4, and 8 weeks after ACL reconstruction by immunohistology for proliferating cell nuclear antigen, VEGF, and CD31, which is a marker for vascular endothelial cells. At week 1 , few cells were observed at the midsubstance of the grafted tendon. A number of proliferating cells were observed at the surface area of the PT graft 2 weeks after graft transplantation, while no vessel formation was observed in the graft at the same time. VEGF was highly expressed 2-3 weeks postoperatively. Vessel formation in the PT graft increased with time from 3 to 8 weeks after ACL reconstruction. The rates of proliferating cells and VEGF-expressing cells decreased with time from 3 to 8 weeks. This study has suggested that VEGF is involved in the graft remodeling process particularly at the early phase after ACL reconstruction. 相似文献
12.
Keiichiro Kume Masahiro Yamasaki Ichiro Yoshikawa Makoto Otsuki 《Digestive endoscopy》2006,18(3):218-220
Background: Although bleeding is an unavoidable complication of endoscopic submucosal dissection (ESD), endoscopic hemostasis using an insulation‐tipped electrosurgical knife (IT) knife is impossible because an insulator is mounted at the tip of the knife. We have developed a new type of hood which could perform both coagulation and irrigation simultaneously. Methods: Our new device was fabricated by drilling a side hole in the cap portion of a conventional transparent hood followed by attaching a machined papillotomy knife to the exterior surface of the hole. Results: Our new hood was useful for hemorrhage during ESD using IT knife. Conclusions: With this method, endoscopic hemostasis using IT knife is easy, as hemostatic procedure can be performed under irrigation and coagulation using conventional endoscopy. 相似文献
13.
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
14.
15.
M Fukumizu T Kurokawa H Yoshikawa S Hanaoka 《No to hattatsu. Brain and development》1991,23(6):617-622
A seven-month-old girl with atypical West syndrome with pedaling automatism was reported. She started to have early infantile epileptic encephalopathy with suppression-burst (EIEE) at age 14 days followed by infantile spasms at 3 months of age. She began to have spasms with automatism at 4 month, mainly consisting of pedaling movements of both feet associated with tonic spasms of upper extremities and writhing of trunk. Ictal EEG showed irregular slow waves with occasional spikes predominantly over the right hemisphere mixed with artifacts. Interictal EEG during sleep showed suppression-burst patterns. Cerebral atrophy and microcephaly were revealed on brain CT, immature myelination on MRI and decreased blood flow in the frontal, temporal, and parietal lobes on the right on PET scan. Pedaling automatism is rare in infancy and its clinical significance was discussed in relation to West syndrome and complex partial seizures. 相似文献
16.
H Ikenaga T Ogihara S Iyori S Kou H Yoshikawa M M Okura 《Postgraduate medical journal》1989,65(768):761-764
A case of a young Japanese woman with long-standing ulcerative colitis complicated by preinfarction angina due to Takayasu's aortitis is presented. Successful emergency aorto-coronary bypass operation was performed. Whether the association of these two diseases can be explained by a common mechanism is discussed. 相似文献
17.
Met-RANTES ameliorates fibrous airway obliteration and decreases ERK expression in a murine model of bronchiolitis obliterans. 总被引:1,自引:0,他引:1
Osamu Uchida Naohiro Kajiwara Aeru Hayashi Kuniharu Miyajima Takayoshi Nagatsuka Hiroki Hayashi Masahiro Taira Masakazu Kimura Masahiro Tsuboi Harubumi Kato 《Annals of thoracic and cardiovascular surgery》2007,13(2):82-86
OBJECTIVES: Bronchiolitis obliterans (BO) is the main cause of late mortality among long-term survivors of lung transplantation. Chemokine-chemokine receptor (CCR) interaction and subsequent recruitment of infiltrating cells to the graft are early events in the development of chronic rejection of transplanted lungs. The present study investigated whether blockade of chemokine receptors CCR1 and CCR5 with Met-regulated-on-activation, normal T cells expressed and secreted (RANTES), an amino-terminal modified derivative of RANTES/CCL5, affects the development of BO in murine model and we sought to determine the expression of RANTES/CCL5 and their relationship with extracellular signal-regulated kinase (ERK). Materials and Methods: BALB/c mouse tracheas were heterotopically transplanted into C57Black6 recipients and treated for 21 days with either Met-RANTES at 20 microg/day or vehicle. Animals were killed at 21 days after transplantation for histologic examination of ERK expression. RESULTS: RANTES/CCL5 was highly expressed in allografts compare to isografts. Met-RANTES treatment ameliorated fibrous airway obliteration in a mouse model of BO and decreased ERK expression. CONCLUSION: Blockade of chemokine receptors by Met-RANTES ameliorated airway obliteration and decreased ERK expression. These findings suggest that chemokine receptors CCR1 and CCR5 play significant roles in the development of chronic rejection and ERK may be a new molecular target for chronic rejection. 相似文献
18.
Hiroki Otani Yutaka Kagaya Yoshio Imahori Satoshi Yasuda Ryo Fujii Masanobu Chida Shigeto Namiuchi Morihiko Takeda Masahito Sakuma Jun Watanabe Tatsuo Ido Hiroshi Nonogi Kunio Shirato 《Journal of nuclear medicine》2005,46(4):553-559
Left ventricular (LV) remodeling after myocardial infarction (MI) is a maladaptive process that increases the risk of heart failure and death. The myocardial phosphoinositide cycle, which is located downstream from several neurohumoral factors, plays a crucial role in LV remodeling. Our animal studies demonstrated that 1-[1-11C]butyryl-2-palmitoyl-rac-glycerol (11C-DAG) can be used to visualize regions with an activated phosphoinositide cycle. Therefore, we examined whether myocardial 11C-DAG accumulation assessed by PET is relevant to LV enlargement and systolic dysfunction in post-MI patients. METHODS: We performed PET with 11C-DAG in 13 post-anteroseptal MI patients and 4 healthy volunteers. We placed regions of interest on the noninfarcted myocardium and calculated the myocardium-to-left atrial (LA) chamber ratio of 11C-DAG accumulation. RESULTS: The myocardium-to-LA chamber ratio of 11C-DAG was significantly higher in the post-MI patients (mean +/- SD, 1.73 +/- 0.35) compared with that of the healthy volunteers (mean +/- SD, 1.25 +/- 0.13; P < 0.05). In the post-MI patients, the myocardium-to-LA chamber ratio of (11)C-DAG was significantly correlated with the LV end-diastolic volume index (r = 0.79, P < 0.01) and the plasma concentration of brain natriuretic peptide (r = 0.85, P < 0.001) and negatively correlated with the LV ejection fraction (r = -0.69, P < 0.01). CONCLUSION: These findings suggest that the myocardial 11C-DAG accumulation assessed by PET is relevant to LV enlargement, LV systolic dysfunction, and humoral activation in post-MI patients. This new imaging strategy based on intracellular signaling may contribute to the assessment and treatment of post-MI patients. 相似文献
19.
20.