全文获取类型
收费全文 | 4619篇 |
免费 | 274篇 |
国内免费 | 30篇 |
专业分类
耳鼻咽喉 | 30篇 |
儿科学 | 120篇 |
妇产科学 | 129篇 |
基础医学 | 676篇 |
口腔科学 | 175篇 |
临床医学 | 370篇 |
内科学 | 1036篇 |
皮肤病学 | 120篇 |
神经病学 | 339篇 |
特种医学 | 288篇 |
外科学 | 584篇 |
综合类 | 85篇 |
预防医学 | 238篇 |
眼科学 | 54篇 |
药学 | 290篇 |
中国医学 | 10篇 |
肿瘤学 | 379篇 |
出版年
2023年 | 33篇 |
2022年 | 64篇 |
2021年 | 109篇 |
2020年 | 61篇 |
2019年 | 87篇 |
2018年 | 94篇 |
2017年 | 75篇 |
2016年 | 93篇 |
2015年 | 95篇 |
2014年 | 121篇 |
2013年 | 169篇 |
2012年 | 285篇 |
2011年 | 249篇 |
2010年 | 138篇 |
2009年 | 132篇 |
2008年 | 232篇 |
2007年 | 251篇 |
2006年 | 233篇 |
2005年 | 258篇 |
2004年 | 224篇 |
2003年 | 203篇 |
2002年 | 197篇 |
2001年 | 87篇 |
2000年 | 85篇 |
1999年 | 88篇 |
1998年 | 59篇 |
1997年 | 59篇 |
1996年 | 70篇 |
1995年 | 38篇 |
1994年 | 43篇 |
1993年 | 38篇 |
1992年 | 57篇 |
1991年 | 62篇 |
1990年 | 52篇 |
1989年 | 88篇 |
1988年 | 72篇 |
1987年 | 74篇 |
1986年 | 71篇 |
1985年 | 49篇 |
1984年 | 29篇 |
1983年 | 36篇 |
1982年 | 21篇 |
1981年 | 25篇 |
1980年 | 23篇 |
1979年 | 37篇 |
1978年 | 26篇 |
1977年 | 23篇 |
1976年 | 21篇 |
1968年 | 25篇 |
1966年 | 25篇 |
排序方式: 共有4923条查询结果,搜索用时 15 毫秒
91.
92.
Ryuichi Yoshimura Ryohei Yamamoto Maki Shinzawa Ryohei Tomi Shingo Ozaki Yoshiyuki Fujii Takafumi Ito Kazuaki Tanabe Yasuaki Moriguchi Yoshitaka Isaka Toshiki Moriyama 《Journal of clinical hypertension (Greenwich, Conn.)》2020,22(4):649-655
Salt sensitivity is one of the crucial risk factors of hypertension. The aim of the present prospective cohort study was to assess the clinical impact of alcohol drinking on an association between salt intake and blood pressure. The present study included 451 employees at a pharmaceutical company in Japan who underwent annual health checkups in both 2017 and 2018. The main exposure of interest was self‐reported drinking frequency at their first checkups: rarely, occasionally, and daily. To assess the association between the change of salt intake estimated from single‐spot urine specimens and that of blood pressure, the differences in systolic/diastolic blood pressure and salt intake between 2017 and 2018 were calculated for each subject. Multivariable‐adjusted linear regression models adjusting for clinically relevant factors clarified a drinking frequency‐dependent association between Δsalt intake and Δsystolic blood pressure (per 1 g/d of Δsalt intake adjusted β [95% confidence interval] 0.19 [−0.73, 1.12], 0.84 [0.14, 1.53], and 1.78 [0.86, 2.69] in rare, occasional, and daily drinkers). A similar association between Δsalt intake and Δdiastolic blood pressure was also observed (−0.24 [−1.02, 0.54], 0.67 (0.18, 1.16), 0.95 [0.38, 1.51], in rare, occasional, and daily drinkers). The interactions between drinking frequency and Δsalt intake were found to be statistically significant (P for interaction = .028 and .006 for ∆systolic blood pressure and ∆diastolic blood pressure, respectively). The present study identified enhanced salt sensitivity in the subjects who drink at a higher frequency, suggesting that the reduction in alcohol consumption may improve salt sensitivity in higher frequency drinkers. 相似文献
93.
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
94.
95.
96.
97.
98.
Miyuki Ushio Maki Kanaoka Yumiko Kinoshita Satoko Maeno Kimie Fujita 《Topics in stroke rehabilitation》2013,20(8):591-598
Background: Physical activity (PA) is beneficial for stroke prevention; in particular, moderate-to-vigorous physical activity (MVPA). However, few studies have investigated its relationship with recurrent ischemic stroke (RIS).Objectives: To clarify the relationship between MVPA and RIS and the burden of risk factors after a first-ever ischemic stroke.Methods: A total of 45 outpatients (mean age 67.1 ± 10.2 years) who had previously experienced a transient ischemic attack or a minor non-cardioembolic ischemic stroke at a single hospital in Japan (mean 6.4 ± 4.2 years previously), were enrolled between March and June 2016. All patients wore an accelerometer around their hips for 10 days, and their percentage body fat (%BF) and visceral fat level (VFL) were measured by bioelectrical impedance. Retrospective information about the history of RIS and risk factors (blood pressure, lipoprotein cholesterol and estimated glomerular filtration rate) were extracted from the clinical records. Binary logistic regression models were used to estimate the relevance of the RIS history to MVPA and potential risk factors such as sociodemographic and clinical variables (obesity, smoking and hypertension).Results: RIS occurred in 9 patients; they had significantly higher VFL (p = 0.007) and %BF (p = 0.007) values and lower MVPA (p = 0.011) values than patients without recurrence. A multivariate analysis of these factors indicated that age, VFL and MVPA were signi?cant independent predictors of RIS.Conclusions: Patients with a history of mild ischemic stroke had low MVPA and high VFL values, which together may be a risk factor for RIS. 相似文献
99.
Maki Yuguchi Taku Toriumi Rie Suzuki Eichi Tsuruga Keitaro Isokawa 《Anatomical record (Hoboken, N.J. : 2007)》2013,296(1):71-78
Dorsoventral fibers in the presumptive dermis of the chick limb bud reported first by Hurle's group in 1989 are now revealed as bundles of fibrillin microfibrils (Isokawa et al., 2004). The bundles, which could be called oxytalan fibers at the light microscopic level, are aligned perpendicularly to the overlying ectoderm and form a unique fiber array, originating directly from the basal lamina. This well‐oriented organization is beneficial in examining the process of in vivo bundling of microfibrils into oxytalan fibers. In this study, sections through the presumptive limb dermis were preferentially prepared from chick embryos at Days 4–6 (ED4‐6). Immunohistochemically, fibrillin‐positive dots representing cross‐sectioned surfaces of individual fibers, increased in size from ED4 to 6, but their number per unit area remained constant. Ultrastructurally, a single oxytalan fiber at ED4 consisted of ~15 microfibrils; the latter number increased fourfold from ED4 to 5 and threefold from ED5 to 6. Oxytalan fibers were all closely associated with mesenchymal cell; notably, the fibers at ED5 and 6 were held in a shallow ditch on the cell body or by lamellipodial cytoplasmic protrusion. In the sites of cell–fiber adhesion, microfibrils in the periphery of an oxytalan fiber appeared to adhere directly or by means of short flocculent strands to a nearby cell membrane; the latter showed a thickening of plasmalemma and its undercoat, indicating the presence of adhesive membrane specification. These findings suggest that the bundling of microfibrils is a progressive and closely cell‐associated process. Anat Rec, 2013. © 2012 Wiley Periodicals, Inc. 相似文献
100.
Ono S Fujishiro M Kodashima S Takahashi Y Minatsuki C Mikami-Matsuda R Asada-Hirayama I Konno-Shimizu M Tsuji Y Mochizuki S Niimi K Yamamichi N Kaneko M Yatomi Y Koike K 《Journal of gastroenterology》2012,47(7):770-774