全文获取类型
收费全文 | 4847篇 |
免费 | 261篇 |
国内免费 | 30篇 |
专业分类
耳鼻咽喉 | 44篇 |
儿科学 | 203篇 |
妇产科学 | 120篇 |
基础医学 | 606篇 |
口腔科学 | 129篇 |
临床医学 | 414篇 |
内科学 | 1042篇 |
皮肤病学 | 76篇 |
神经病学 | 375篇 |
特种医学 | 253篇 |
外科学 | 556篇 |
综合类 | 22篇 |
一般理论 | 1篇 |
预防医学 | 405篇 |
眼科学 | 66篇 |
药学 | 316篇 |
中国医学 | 10篇 |
肿瘤学 | 500篇 |
出版年
2024年 | 6篇 |
2023年 | 39篇 |
2022年 | 78篇 |
2021年 | 147篇 |
2020年 | 113篇 |
2019年 | 133篇 |
2018年 | 133篇 |
2017年 | 98篇 |
2016年 | 124篇 |
2015年 | 144篇 |
2014年 | 188篇 |
2013年 | 247篇 |
2012年 | 405篇 |
2011年 | 424篇 |
2010年 | 218篇 |
2009年 | 175篇 |
2008年 | 313篇 |
2007年 | 318篇 |
2006年 | 287篇 |
2005年 | 288篇 |
2004年 | 268篇 |
2003年 | 220篇 |
2002年 | 178篇 |
2001年 | 64篇 |
2000年 | 45篇 |
1999年 | 40篇 |
1998年 | 33篇 |
1997年 | 30篇 |
1996年 | 16篇 |
1995年 | 19篇 |
1994年 | 23篇 |
1993年 | 12篇 |
1992年 | 23篇 |
1991年 | 27篇 |
1990年 | 20篇 |
1989年 | 22篇 |
1988年 | 17篇 |
1987年 | 32篇 |
1986年 | 18篇 |
1985年 | 39篇 |
1984年 | 18篇 |
1983年 | 8篇 |
1982年 | 9篇 |
1979年 | 7篇 |
1978年 | 5篇 |
1971年 | 4篇 |
1970年 | 4篇 |
1969年 | 14篇 |
1968年 | 8篇 |
1967年 | 7篇 |
排序方式: 共有5138条查询结果,搜索用时 0 毫秒
101.
Bayasula Iwase A Kiyono T Takikawa S Goto M Nakamura T Nagatomo Y Nakahara T Kotani T Kobayashi H Kondo M Manabe S Kikkawa F 《Endocrinology》2012,153(6):2851-2860
The ovary is a complex endocrine organ responsible for steroidogenesis and folliculogenesis. Follicles consist of oocytes and two primary steroidogenic cell types, the granulosa cells, and the theca cells. Immortalized human granulosa cells are essential for researching the mechanism of steroidogenesis and folliculogenesis. We obtained granulosa cells from a 35-yr-old female and immortalized them by lentivirus-mediated transfer of several genes so as to establish a human nonluteinized granulosa cell line (HGrC1). We subsequently characterized HGrC1 and investigated its steroidogenic performance. HGrC1 expressed enzymes related to steroidogenesis, such as steroidogenic acute regulatory protein, CYP11A, aromatase, and gonadotropin receptors. Stimulation with FSH increased the mRNA levels of aromatase, which consequently induced the aromatization of androstenedione to estradiol. Activin A increased the mRNA levels of the FSH receptor, which were synergistically up-regulated with FSH stimulation. HGrC1 also expressed a series of ligands and receptors belonging to the TGF-β superfamily. A Western blot analysis showed that bone morphogenetic protein (BMP)-4, BMP-6, and BMP-7 phosphorylated small mother against decapentaplegic (Smad)1/5/8, whereas growth differentiation factor-9 phosphorylated Smad2/3. BMP-15 and anti-Müllerian hormone phosphorylated Smad1/5/8 while also weakly phosphorylating Smad2/3. These results indicate that HGrC1 may possess the characteristics of granulosa cells belonging to follicles in the early stage. HGrC1 might also be capable of displaying the growth transition from a gonadotropin-independent status to gonadotropin-dependent one. 相似文献
102.
103.
JR Raiko M Oikonen M Wendelin-Saarenhovi N Siitonen M Kähönen T Lehtimäki J Viikari A Jula BM Loo R Huupponen L Saarikoski M Juonala OT Raitakari 《Atherosclerosis》2012,224(1):208-212
AimsHypofibrinolysis displayed by elevated serum plasminogen activator inhibitor 1 (PAI-1) level has been associated with cardiovascular disease (CVD) and its risk factors such as obesity and insulin resistance. However, no studies have examined associations between PAI-1 and CVD risk factors in healthy subjects. We examined associations between serum PAI-1, ultrasound markers of atherosclerosis and CVD risk factors and whether PAI-1 improves prediction of atherosclerosis over known risk factors in a cohort of asymptomatic adults.MethodsWe analyzed PAI-1 and CVD risk factors and assessed carotid intima-media thickness (cIMT), distensibility (CDist) and the presence of a carotid atherosclerotic plaque and flow-mediated dilation (FMD) ultrasonographically for 2202 adults (993 men and 1,209 women, aged 30–45 years) participating in the ongoing longitudinal cohort study, The Cardiovascular Risk in Young Finns Study. High cIMT was defined as >90th percentile and/or carotid plaque and low CDist and low FMD as <20th percentile.ResultsIn bivariate analyses, PAI-1 correlated directly with cIMT and the risk factors: blood pressure, BMI, waist and hip circumference, alcohol use, total and LDL-cholesterol, triglycerides, glomerular filtration rate, high-sensitivity CRP and glucose (all P < 0.005). PAI-1 was higher in men and increased with age. Inverse correlation was observed with CDist, HDL-cholesterol and adiponectin in both sexes, with testosterone and sex hormone binding globulin in men and with creatinine and oral contraceptive use in women (P < 0.005). Independent direct associations were observed between PAI-1 and waist circumference, serum triglycerides, insulin, alcohol use and age and inverse with serum creatinine, HDL-cholesterol and adiponectin. PAI-1 did not improve estimation of high cIMT, low CDist and low FMD over conventional risk factors (P for difference in area under curve ≥ 0.37).ConclusionPAI-1 was independently associated with several known CVD risk factors, especially obesity markers, in both men and women. However, addition of PAI-1 to known risk factors did not improve cross-sectional prediction of high cIMT, low CDist and low FMD suggesting that PAI-1 is not a clinically important biomarker in early atherosclerosis. 相似文献
104.
105.
106.
Costan G. Magnussen Juha Koskinen Markus Juonala Wei Chen Sathanur R. Srinivasan Matthew A. Sabin Russell Thomson Michael D. Schmidt Quoc Manh Nguyen Ji-Hua Xu Michael R. Skilton Mika Kähönen Tomi Laitinen Leena Taittonen Terho Lehtimäki Tapani Rönnemaa Jorma S.A. Viikari Gerald S. Berenson Olli T. Raitakari 《Journal of the American College of Cardiology》2012
107.
Olli Hartiala Costan G. Magnussen Sami Kajander Juhani Knuuti Heikki Ukkonen Antti Saraste Irina Rinta-Kiikka Sakari Kainulainen Mika Kähönen Nina Hutri-Kähönen Tomi Laitinen Terho Lehtimäki Jorma S.A. Viikari Jaakko Hartiala Markus Juonala Olli T. Raitakari 《Journal of the American College of Cardiology》2012
108.
Fiia Takio Mika Koivisto Tuulikki Tuominen Seppo J. Laukka Heikki Hämäläinen 《Laterality》2013,18(1):44-67
Age-related changes in visual spatial biases in children, young adults, and older adults were studied with unilateral and bilateral stimulus conditions in fast-paced linguistic and non-linguistic attention tasks. Only rightward spatial biases were observed. The incidence of the biases changed as a function of age: in childhood and in old age the rightward spatial biases were more common than in young adulthood. The present rightward spatial biases were similar to those observed in the corresponding auditory spatial linguistic and non-linguistic attention tests (Takio, Koivisto, Laukka, & Hämäläinen, 2011) and in the dichotic listening forced-attention task (Takio et al., 2009). We suggest that the multimodal rightward spatial bias observed under intensive attentional load is related to a right hemispace preference and modulated by age-dependent changes in executive functions. 相似文献
109.
110.
Mika Shishido Hirofumi Sawai Kaoru Inami Yuko Katao Naoyuki Matsumoto 《Orthodontic Waves》2013,72(2):43-48
PurposeIn orthodontic tooth movement, osteoclasts play a crucial role in bone resorption on the compression side of the alveolar bone. It has been reported that nitric oxide is involved in bone remodeling caused by mechanical loading, and we previously reported that NOC-18, a long-acting nitric oxide donor, augmented RANKL-induced osteoclast differentiation in mouse monocytic RAW264 cells as well as mouse bone marrow macrophages. In this study, we investigated whether NOC-18 facilitated experimental tooth movement in mice.Materials and methodsEight-week-old male ddY mice were used. Experimental tooth movement was induced by the insertion of an orthodontic elastic between the left maxillary first molar and second molar. Just after the insertion of the elastic, NOC-18 was intraperitoneally administered once, and mice were killed after 3 days. For the detection of osteoclasts, HE staining, TRAP staining, and immunostaining for cathepsin K were performed.ResultsAn intraperitoneal injection of NOC-18 significantly increased the distance of experimental tooth movement. Furthermore, the number and area of osteoclasts on the compression side of the alveolar bone surface was significantly higher in the NOC-18 group.ConclusionThese results suggested that systemic administration of NOC-18 might have some effect to facilitate experimental tooth movement in mice via the augmentation of osteoclast differentiation on the compression side of the alveolar bone. 相似文献