全文获取类型
收费全文 | 1377篇 |
免费 | 55篇 |
国内免费 | 8篇 |
专业分类
耳鼻咽喉 | 32篇 |
儿科学 | 40篇 |
妇产科学 | 81篇 |
基础医学 | 71篇 |
口腔科学 | 48篇 |
临床医学 | 111篇 |
内科学 | 317篇 |
皮肤病学 | 59篇 |
神经病学 | 86篇 |
特种医学 | 35篇 |
外科学 | 340篇 |
综合类 | 17篇 |
预防医学 | 72篇 |
眼科学 | 43篇 |
药学 | 55篇 |
肿瘤学 | 33篇 |
出版年
2023年 | 4篇 |
2022年 | 4篇 |
2021年 | 25篇 |
2020年 | 13篇 |
2019年 | 25篇 |
2018年 | 37篇 |
2017年 | 23篇 |
2016年 | 45篇 |
2015年 | 29篇 |
2014年 | 30篇 |
2013年 | 65篇 |
2012年 | 102篇 |
2011年 | 86篇 |
2010年 | 49篇 |
2009年 | 74篇 |
2008年 | 127篇 |
2007年 | 138篇 |
2006年 | 114篇 |
2005年 | 126篇 |
2004年 | 109篇 |
2003年 | 78篇 |
2002年 | 64篇 |
2001年 | 27篇 |
2000年 | 19篇 |
1999年 | 12篇 |
1998年 | 1篇 |
1997年 | 5篇 |
1996年 | 1篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1984年 | 1篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1974年 | 1篇 |
排序方式: 共有1440条查询结果,搜索用时 15 毫秒
41.
42.
The aim of this study was to demonstrate an assessment of left internal mammary artery (LIMA) patency and anatomy by standard left ventriculography, and to define a proposal for predicting LIMA function according to left ventriculography outcome. A total of 335 patients with an indication of coronary angiography were included. Standard coronary angiography and left ventriculography were performed initially. Visualization of LIMA occurred in the late phase of ventriculography and the LIMA visualization frame rate was counted for each patient. Then selective LIMA angiography was performed and LIMA diameter, LIMA course and anatomy, and subclavian artery anatomy were noted. Finally, the results of left ventriculography and LIMA angiography were compared by statistical analysis. During left ventriculography, LIMA was visualized in 96.4% of the patients. The mean LIMA visualization frame rate was 53.8 ± 17.7 and the mean LIMA diameter was 2.60 ± 0.36 mm. There was a strong correlation between LIMA visualization frame rate and LIMA diameter, LIMA course, and also asymptomatic subclavian artery disease (P < 0.001). Regression analysis showed that LIMA visualization frame rate is the major independent determinant for LIMA diameter prediction (P < 0.001); LIMA diameter, LIMA course, proximal LIMA side branch, and subclavian artery disease are the major predictors of LIMA visualization on left ventriculography (P < 0.001). LIMA patency and anatomy can be evaluated accurately with a simple method using left ventriculography. Besides direct visualization of LIMA, the visualization frame rate may constitute a reliable parameter for assessing LIMA function. A LIMA visualization frame rate of less than 50 is associated with a healthy and well-sized LIMA. 相似文献
43.
Aslan M Celik O Celik N Turkcuoglu I Yilmaz E Karaer A Simsek Y Celik E Aydin S 《Endocrine》2012,41(3):424-429
To assess maternal serum and cord blood apelin-36 and nesfatin-1 concentrations in pregnant women with and without gestational diabetes mellitus (GDM). Thirty pregnant women with GDM and 30 gestational age matched healthy pregnant subjects participated to the study. Maternal serum and cord blood nesfatin-1 and apelin-36 levels were measured with ELISA, at the time of birth. The relationships between maternal serum and cord blood nesfatin-1 and apelin-36 levels, anthropometric and metabolic parameters were also assessed. Maternal serum apelin-36 levels were found higher (13.5?±?8.3 vs. 9.6?±?5.9?ng/ml, P?=?0.001) and nesfatin-1 levels were found lower (5.5?±?8.1 vs. 8.1?±?23.9?ng/ml, P?=?0.001) in patients with GDM compared with control pregnant women. However, the cord blood apelin-36 levels (8.8?±?4.3 and 8.2?±?1.9?ng/ml, P?=?0.618) and nesfatin-1 levels (5.4?±?4.0 and 6.2?±?10.3?ng/ml, P?=?0.688) were similar in the GDM and control groups, respectively. Maternal serum apelin-36 and nesfatin-1 levels correlated positively with their respective cord blood levels. Maternal serum and cord blood apelin-36 levels correlated negatively with the gestational age and birth weight. Similarly maternal serum and cord blood nesfatin-1 levels correlated negatively with the gestational age, but there was no correlation with the birth weight. We did not find a correlation between maternal serum apelin-36 and nesfatin-1 levels, maternal age, BMI, fasting glucose, fasting insulin, and HOMA-IR. Also cord blood apelin-36 and nesfatin-1 levels did not correlate with the maternal age, BMI, HOMA-IR, cord blood glucose, and cord blood insulin levels. Our results indicate that apelin-36 concentrations increase and nesfatin-1 concentrations decrease in maternal serum of women with GDM. 相似文献
44.
45.
The effects of aging on the central nervous system steroid profiles and myelin basic protein in rats
Ciftci G Yarim GF Yarim M Karayigit MO Cenesiz S Nisbet C Gultiken ME 《Aging clinical and experimental research》2012,24(2):117-124
The aim of this study was to investigate the effects of aging on the central nervous system steroid and myelin basic protein (MBP) profiles. Forty-seven male Sprague-Dawley rats (newborn, 1, 6, 12 and 24-monthsold) were studied. Tissues were obtained from the cerebellum and parietal, frontal, temporal cortex of the central nervous system of the rats for steroid extraction. The estradiol, progesteron, testosterone and dehydroepiandrosterone (DHEA) levels were measured by Enzyme Linked Immunosorbent Assay (ELISA). The average levels of estradiol (pg/g), progesteron (ng/g), DHEA (ng/g) and testosterone (ng/g) in the brain tissues were respectively 24.29, 4.59, 0.27, 0.92 in the newborn-rats; 4.18 ± 1.10, 1.54 ± 0.30, 0.28 ± 0.01, 0.57 ± 0.10 in the 1 month-old-rats; 11.02 ± 1.10, 2.96 ± 0.30, 0.27 ± 0.01, 0.61 ± 0.10 in the 6 month-old-rats; 15.80 ± 1.10, 4.80 ± 0.30, 0.28 ± 0.10, 0.67 ± 0.10 in the 12 monthold- rats; 20.07 ± 1.10, 4.12 ± 0.30, 0.28 ± 0.01, 0.55±0.10 in the 24 month-old-rats. The myelin basic protein levels were determined by immunohistochemical staining and an elevation was observed in conjunction with the aging process. The results of the study indicate that the alterations in MBP, DHEA, progesterone, testosterone and estrodiol concentrations in the central nervous system of the rats during aging can be considered fundamental for future animal and human studies. 相似文献
46.
Dorukcan Akincioglu Gokhan Ozge Onder Ayyildiz Gokcen Gokce Umut Kara Fatih Mehmet Mutlu 《国际眼科》2021,14(12):1963-1969
AIM: To evaluate the clinical use of Fourier analysis of videokeratography data in the diagnosis and follow-up of keratoconus (KC).
METHODS: We conducted a chart review of consecutive patients presented to our cornea clinic. A team of two experienced cornea specialists divided the patients into three groups: normal cornea, forme fruste KC (FFKC), and clinical KC. The exclusion criteria were a history of previous ocular surgery, any accompanying corneal pathology other than KC, high myopia (>6.00 diopters), amblyopia, pregnancy, breastfeeding, or any current autoimmune disease. The data of Fourier series harmonic analysis were evaluated for their diagnostic capacity using the receiver operating characteristic (ROC) curve. A binary logistic regression analysis was also conducted to construct a diagnostic model. A total of 259 eyes showed progression in the clinical KC group and underwent a combination of accelerated corneal collagen cross-linking and topography-guided customized treatment with an excimer laser.
RESULTS: The study included 1262 eyes (618 normal, 530 KC, and 114 FFKC) of 1262 patients. We observed that maximum decentration (MaxDec) was almost as good as maximum keratometry (Kmax) in detecting progressive KC. The area under the curve (AUC) was 0.95 for KC [95% confidence interval (CI): 0.93-0.96] and 0.84 for FFKC (95%CI: 0.79-0.88). Higher predictive accuracy was obtained using a model combining the spherical component, MaxDec, irregularity, and regular astigmatism in the center of the cornea (AUC: 0.97; sensitivity: 89%, and specificity: 96%).
CONCLUSION: Decentration, Kmax, and posterior radii of curvatures from a 3.0-mm optical zone centered on the thinnest point of the cornea provide the highest accuracy with low reproducibility of Kmax. 相似文献
47.
48.
49.
A platinum blue complex exerts its cytotoxic activity via DNA damage and induces apoptosis in cancer cells 下载免费PDF全文
Zelal Adiguzel Seniz Ozalp‐Yaman Gokalp Celik Safia Salem Tugba Bagci‐Onder Filiz Senbabaoglu Yüksel Cetin Ceyda Acilan 《Chemical biology & drug design》2017,90(2):210-224
Here, we describe the characteristics of a Pt‐blue complex [Pt4(2‐atp)8(H2O)(OH)] (2‐atp: 2‐aminothiophenol) as a prodrug for its DNA‐binding properties and its use in cancer therapy. The nature of the interaction between the Pt‐blue complex and DNA was evaluated based on spectroscopic measurements, the electronic absorption spectra, thermal behavior, viscosity, fluorometric titration, and agarose gel electrophoresis. Our results suggested that the compound was able to partially intercalate DNA and appeared to induce both single‐ and double‐stranded breaks (DBS) on DNA in vitro, but no DSBs in cells. The ability of the compound to induce DNA damage was dependent on reactive oxygen species (ROS) in vitro. There was also elevated formation of ROS and SOD expression in response to drug treatment in cell culture. The complex was found to be more cytotoxic to cancer cells in comparison with noncancer controls using WST‐1 assay. The mean of cell death was determined to be apoptosis as assessed via biochemical, morphological, and molecular observations, including DNA condensation/fragmentation analysis, live cell imaging microscopy, TUNEL analyses, and increase in the levels of pro‐apoptotic genes such as Bag3, Bak, Bik, Bmf, and Hrk. Hence, the Pt‐blue complex under study grants premise for further studies. 相似文献
50.