全文获取类型
收费全文 | 3751篇 |
免费 | 180篇 |
国内免费 | 69篇 |
专业分类
耳鼻咽喉 | 76篇 |
儿科学 | 66篇 |
妇产科学 | 153篇 |
基础医学 | 618篇 |
口腔科学 | 82篇 |
临床医学 | 313篇 |
内科学 | 618篇 |
皮肤病学 | 102篇 |
神经病学 | 224篇 |
特种医学 | 155篇 |
外科学 | 620篇 |
综合类 | 113篇 |
预防医学 | 160篇 |
眼科学 | 60篇 |
药学 | 367篇 |
中国医学 | 33篇 |
肿瘤学 | 240篇 |
出版年
2023年 | 29篇 |
2022年 | 51篇 |
2021年 | 94篇 |
2020年 | 58篇 |
2019年 | 68篇 |
2018年 | 92篇 |
2017年 | 83篇 |
2016年 | 98篇 |
2015年 | 144篇 |
2014年 | 168篇 |
2013年 | 166篇 |
2012年 | 261篇 |
2011年 | 264篇 |
2010年 | 161篇 |
2009年 | 117篇 |
2008年 | 188篇 |
2007年 | 205篇 |
2006年 | 199篇 |
2005年 | 169篇 |
2004年 | 144篇 |
2003年 | 120篇 |
2002年 | 113篇 |
2001年 | 106篇 |
2000年 | 94篇 |
1999年 | 89篇 |
1998年 | 36篇 |
1997年 | 27篇 |
1996年 | 44篇 |
1995年 | 34篇 |
1994年 | 24篇 |
1993年 | 19篇 |
1992年 | 35篇 |
1991年 | 44篇 |
1990年 | 38篇 |
1989年 | 41篇 |
1988年 | 21篇 |
1987年 | 25篇 |
1986年 | 23篇 |
1985年 | 33篇 |
1984年 | 20篇 |
1983年 | 14篇 |
1979年 | 16篇 |
1978年 | 21篇 |
1977年 | 14篇 |
1976年 | 13篇 |
1975年 | 17篇 |
1974年 | 17篇 |
1973年 | 14篇 |
1972年 | 18篇 |
1966年 | 16篇 |
排序方式: 共有4000条查询结果,搜索用时 15 毫秒
101.
Madsen G Zakar T Ku CY Sanborn BM Smith R Mesiano S 《The Journal of clinical endocrinology and metabolism》2004,89(2):1010-1013
We tested the hypothesis that prostaglandin (PGs), PGE2, and PGF2 alpha, stimulate labor and delivery in women, in part, by inducing functional progesterone withdrawal in myometrial cells by increasing the progesterone receptor (PR)-A/PR-B expression ration. PHM1-31 cells (an immortal pregnant human myometrial cell line) were exposed to PGE2, PGF2 alpha, cyclic-8-bromoadenosine monophosphate (8-Br-cAMP) and phorbol 12-myristate 13-acetate (PMA) at various concentrations for 24h. Effects on PR-A and PR-B expression were then assessed by quantitative RT-PCR. PGF2 alpha dose dependently increased PR-A mRNA and the PR-A/PR-B expression ration but did not effect PR-B mRNA. PGE2 dose-dependently increased mRNAs encoding PR-A and PR-B. The PGE2 dose-threshold for PR-A (0.01 nM) was lower than that for PR-B (0.1 nM), which resulted in an initial rise then a gradual fall in PR-A/PR-B expression ration to basal levels in response to PGE2. Activation of the protein kinase (PK)-A signaling pathway with 8-Br-cAMP coordinately increased expression of PR-A and PR-B and therefore did not alter the PR-A/PR-B expression ration. In contrast, activation of the PKC signaling pathway with PMA increased expression of PR-A without affecting PR-B and therefore significantly (P<0.05) increased the PR-A/PR-B expression ration. These data demonstrate differential control of myometrial PR-A and PR-B expression by PGE2 and PGF2 alpha and by specific intracellular signaling pathways. We conclude that PGs acting via the PKC pathway facilitate functional progesterone withdrawal by increasing the myometrial PR-A/PR-B expression ratio. 相似文献
102.
Background
Incidence of fragmented (fQRS) and predisposing factors in patients with implantable cardioverter-defibrillator (ICD) have not yet been established.AimTo examine incidence of fQRS, associated factors as well as predictive value in identifying site of coronary artery disease (CAD).Methods
Consecutive patients with ICD. Retrospective analysis of demographic, clinical and ECG data.Results
Of 382 patients, 163 (43%) had fQRS. They had more frequently history of MI, Q wave, lower left ventricular ejection fraction and prolonged ECG repolarisation indices. The presence of fQRS in more than one ECG localisation was associated with higher number of MI and ICD for secondary prevention. By combining fQRS with Q wave location, site of CAD could be predicted (total accuracy 84–95%).Conclusions
The fQRS is frequent in patients with ICD, especially those with CAD, more advanced cardiac disease and altered ECG repolarisation. The fQRS may improve ECG-based non-invasive identification of the site of CAD. 相似文献103.
Clinical significance of bile reflux into the pancreatic duct without pancreaticobiliary maljunction assessed by intraoperative cholangiography
下载免费PDF全文
![点击此处可从《Asian journal of endoscopic surgery》网站下载免费的PDF全文](/ch/ext_images/free.gif)
104.
105.
106.
107.
108.
In Ku Yo Oh Sang Kwon Jin Woong Park Jong Joon Lee Jung Hyun Lee In Sik Won Sun Young Na Pil Kyu Jang Pyung Hwa Park Duck Joo Choi Yun Soo Kim Ju Hyun Kim 《Clinical and molecular hepatology》2015,21(1):32-40
Background/Aims
Liver stiffness (LS) as assessed by transient elastography (TE) can change longitudinally in patients with chronic hepatitis B (CHB). The aim of this study was to identify the factors that improve LS.Methods
Between April 2007 and December 2012, 151 patients with CHB who underwent two TE procedures with an interval of about 2 years were enrolled. Ninety-six of the 151 patients were treated with nucleos(t)ide analogues [the antiviral therapy (+) group], while the remaining 55 patients were not [the antiviral therapy (-) group]. The two groups of patients were stratified according to whether they exhibited an improvement or a deterioration in LS during the study period (defined as an LS change of ≤0 or >0 kPa, respectively, over a 1-year period), and their data were compared.Results
No differences were observed between the antiviral therapy (+) and (-) groups with respect to either their clinical characteristics or their initial LS. The observed LS improvement was significantly greater in the antiviral therapy (+) group than in the antiviral therapy (-) group (-3.0 vs. 0.98 kPa, P=0.011). In the antiviral therapy (+) group, the initial LS was higher in the LS improvement group (n=63) than in the LS deterioration group (n=33; 7.9 vs. 4.8 kPa, P<0.001). However, there were no differences in any other clinical characteristic. In the antiviral therapy (-) group, the initial LS was also higher in the LS improvement group (n=29) than in the LS deterioration group (n=26; 8.3 vs. 6.5 kPa, P=0.021), with no differences in any other clinical characteristic.Conclusions
A higher initial LS was the only factor associated with LS improvement in patients with CHB in this study. 相似文献109.
Ming Jiang Wei-Yao Ku Zhongren Zhou Evan S. Dellon Gary W. Falk Hiroshi Nakagawa Mei-Lun Wang Kuancan Liu Jun Wang David A. Katzka Jeffrey H. Peters Xiaopeng Lan Jianwen Que 《The Journal of clinical investigation》2015,125(4):1557-1568
Tissue homeostasis requires balanced self-renewal and differentiation of stem/progenitor cells, especially in tissues that are constantly replenished like the esophagus. Disruption of this balance is associated with pathological conditions, including eosinophilic esophagitis (EoE), in which basal progenitor cells become hyperplastic upon proinflammatory stimulation. However, how basal cells respond to the inflammatory environment at the molecular level remains undetermined. We previously reported that the bone morphogenetic protein (BMP) signaling pathway is critical for epithelial morphogenesis in the embryonic esophagus. Here, we address how this pathway regulates tissue homeostasis and EoE development in the adult esophagus. BMP signaling was specifically activated in differentiated squamous epithelium, but not in basal progenitor cells, which express the BMP antagonist follistatin. Previous reports indicate that increased BMP activity promotes Barrett’s intestinal differentiation; however, in mice, basal progenitor cell–specific expression of constitutively active BMP promoted squamous differentiation. Moreover, BMP activation increased intracellular ROS levels, initiating an NRF2-mediated oxidative response during basal progenitor cell differentiation. In both a mouse EoE model and human biopsies, reduced squamous differentiation was associated with high levels of follistatin and disrupted BMP/NRF2 pathways. We therefore propose a model in which normal squamous differentiation of basal progenitor cells is mediated by BMP-driven NRF2 activation and basal cell hyperplasia is promoted by disruption of BMP signaling in EoE. 相似文献
110.
目的观察产后盆底肌训练对提高盆底肌力、改善尿失禁及盆腔脏器脱垂的效果。方法选取94例产后盆底功能障碍性疾病患者,随机分为两组,各47人。观察组采用标准的盆底肌训练,每周进行2次,5周为1个疗程;对照组完成相关健康教育和练习产后操。两组患者治疗前后均进行盆底肌力测定以及评价压力性尿失禁和盆腔脏器脱垂的发生情况。结果观察组与对照组盆底肌力治疗有效率分别为66.0%和89.4%,压力性尿失禁治疗有效率分别为59.6%和78.7%,盆腔脏器脱垂治疗有效率分别为57.4%和74.5%,差异均有统计学意义(P<0.05)。结论产后盆底肌训练对提高盆底肌力、改善尿失禁及盆腔脏器脱垂效果较好,值得推广应用。 相似文献