全文获取类型
收费全文 | 3739篇 |
免费 | 191篇 |
国内免费 | 16篇 |
专业分类
耳鼻咽喉 | 95篇 |
儿科学 | 227篇 |
妇产科学 | 160篇 |
基础医学 | 374篇 |
口腔科学 | 119篇 |
临床医学 | 355篇 |
内科学 | 747篇 |
皮肤病学 | 128篇 |
神经病学 | 206篇 |
特种医学 | 143篇 |
外科学 | 539篇 |
综合类 | 76篇 |
预防医学 | 250篇 |
眼科学 | 79篇 |
药学 | 268篇 |
中国医学 | 19篇 |
肿瘤学 | 161篇 |
出版年
2024年 | 12篇 |
2023年 | 54篇 |
2022年 | 101篇 |
2021年 | 168篇 |
2020年 | 109篇 |
2019年 | 164篇 |
2018年 | 155篇 |
2017年 | 114篇 |
2016年 | 176篇 |
2015年 | 147篇 |
2014年 | 175篇 |
2013年 | 238篇 |
2012年 | 320篇 |
2011年 | 302篇 |
2010年 | 171篇 |
2009年 | 162篇 |
2008年 | 201篇 |
2007年 | 251篇 |
2006年 | 208篇 |
2005年 | 202篇 |
2004年 | 177篇 |
2003年 | 105篇 |
2002年 | 99篇 |
2001年 | 23篇 |
2000年 | 9篇 |
1999年 | 12篇 |
1998年 | 10篇 |
1997年 | 13篇 |
1996年 | 6篇 |
1995年 | 6篇 |
1994年 | 6篇 |
1993年 | 4篇 |
1992年 | 10篇 |
1991年 | 4篇 |
1990年 | 5篇 |
1989年 | 2篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1980年 | 1篇 |
1976年 | 2篇 |
1974年 | 1篇 |
1973年 | 2篇 |
1971年 | 2篇 |
1960年 | 1篇 |
1958年 | 1篇 |
排序方式: 共有3946条查询结果,搜索用时 15 毫秒
991.
Ali Bay Mehmet Keskin Samil Hizli Hatice Uygun Alper Dai Fatma Gumruk 《International journal of hematology》2010,92(3):524-526
Thiamine-responsive megaloblastic anemia (TRMA) syndrome usually associated with diabetes mellitus, anemia and deafness, due to mutations in SLC19A2, encoding a thiamine transporter protein. The onset of disease is usually seen during infancy or at early childhood and most of the TRMA patients are originated from consanguineous families. In this case, we report a 5-month-old boy who had diagnosis of TRMA during evaluations for his anemia and thrombocytopenia. The diagnosis of TRMA should be kept in mind in differential diagnosis of megaloblastic anemia especially in the populations where the consanguinity is frequent. 相似文献
992.
993.
Intradural schwannoma of the conus medullaris is a rare form of spinal neoplasm, which commonly occurs in the lumbar region. Conus medullaris level is unusual for schwannomas. A 49-year-old woman presented with chronic sciatica, mild bladder dysfunction, and paresthesia in the buttocks. Magnetic resonance imaging of the spine showed a mass lesion in the conus medullaris region with nerve compression. The tumor was completely resected and diagnosed histologically as schwannoma. The patient recovered after surgery. Clinical and radiologic features of this rare tumor are reviewed and are accompanied by literature findings. 相似文献
994.
995.
Gulgun Yilmaz Ovali Omer Yilmaz Serdar Tarhan Abdulkadir Genc Peyker Demireli Ozum Tun?yurek Cansu Unden Can Taneli Yüksel Pabuscu 《Canadian Urological Association journal》2009,3(5):383-386
Introduction:
In this study, we define the characteristics of perfusion computed tomography (CT) in an experimental model of testicular torsion.Methods:
Twenty male Sprague-Dawley rats were included for the study. Torsion was applied to 10 rats and perfusion CT was performed in the first hour to evaluate the following perfusion parameters: blood flow (BF), blood volume (BV) and time to peak (TTP) values. Detorsion was done for the same rats, and perfusion CT was repeated 2 hours later to evaluate reperfusion. Ten rats were left as part of the control group.Results:
There is significant statistical correlation between the BF and BV values in the torsion and control groups (p = 0.001 and p = 0.001, respectively). There is no statistical correlation of the TTP parameters between the groups. No correlation was found between torsion and detorsion perfusion parameters.Conclusion:
Perfusion CT can demonstrate the testicular perfusion insult in an experimental model of torsion. Perfusion CT may be an alternative method for diagnosis of torsion in indeterminate cases. Following detorsion an interval of 2 hours is not sufficient for demonstrating luxury perfusion of the testis. 相似文献996.
In this paper, a more effective use of Doppler techniques is presented for the purpose of diagnosing atherosclerosis in its
early stages using the carotid artery Doppler signals. The power spectral density (PSD) graphics are obtained by applying
the short-time Fourier transform (STFT)-Welch and the Eigenvector MUSIC methods to the discrete wavelet transform (DWT) of
Doppler signals. The PSDs for the fourth approximation component (A4) of both methods estimated that the patients with atherosclerosis
in its early phase had lower maximum frequency components. On the other hand, the healthy subjects had higher maximum frequency
components. The area under the curve (AUC), which belongs to the receiver operating characteristic (ROC) curve for the frequency
level of the maximum PSDs of the A4 approximation obtained from the STFT modeling, is computed as 0.97. The AUC for the MUSIC
modeling is computed as 0.996. The AUC belonging to the ROC curve for the higher maximum frequency component is computed as
0.87. The AUC belonging to the ROC curve for the test parameter of the frequency level of the maximum PSDs derived from the
MUSIC modeling is determined to be 0.882. The results of this study clearly demonstrate that it is possible to distinguish
between the healthy people and the patients with atherosclerosis by using the frequency level of the maximum PSDs for the
A4 approximation. Furthermore, it is concluded that the power of Eigenvector-MUSIC method in terms of the resolution of the
high frequencies is better than that of the STFT methods. 相似文献
997.
998.
999.
Tok D Ilkgul O Bengmark S Aydede H Erhan Y Taneli F Ulman C Vatansever S Kose C Ok G 《The Journal of trauma》2007,62(4):880-885
BACKGROUND: To study whether enteral pretreatment with a synbiotic composition of lactic acid bacteria and bioactive fibers can reduce peritonitis-induced lung neutrophil infiltration and tissue injury in rats. MATERIALS AND METHODS: Rats were divided into five groups, and subjected to induction of peritonitis-induced lung injury using a cecal ligation and puncture model (CLP). All animals were pretreated for 3 weeks prior the CLP by daily gavage with either (1) a synbiotic composition (10(10) CFU of Pediococcus pentosaceus 5-33:3, 10(10) CFU of Leuconostoc mesenteroides 77:1, 10(10) CFU of L. paracasei subspecies paracasei, 10(10) CFU of L. plantarum 2362 plus fermentable fibers), (2) fermentable fibers alone, (3) nonfermentable fibers, (4) a probiotic composition (10(10) CFU of P. pentosaceus 5-33:3, 10(10) CFU of L. mesenteroides 77:1, 10(10) CFU of L. paracasei subsp. paracasei, 10(10) CFU of L. plantarum 2,362), or (5) a heat-killed probiotic composition. All animals were killed 24 hours after CLP and lung tissue samples were studied for degree of neutrophil infiltration and levels of tumor necrosis factor (TNF)-alpha, Interleukin (IL)-1beta. In addition the lung wet-to-dry tissue weight ratio, the myeloperoxidase activity, and malondialdehyde content were also assessed. RESULTS: No mortality was encountered in any of the groups. Histologic signs of lung injury (number of neutrophils and TNF-alpha, IL-1beta staining) were observed in all groups except the synbiotic and probiotic treated groups. Myeloperoxidase activity and malondialdehyde content were significantly lower in the two lactobacillus- pretreated groups, with no difference between them. Heavy infiltration of lung tissue with neutrophils was observed only in fiber-treated (302.20 +/- 7.92) and placebo-treated (266.90 +/- 8.92) animals. This was totally abolished in the synbiotic-treated group (34.40 +/- 2.49). Lung edema (wet-to-dry lung weight ratio) was significantly reduced in the synbiotic-treated group (4.92 +/- 0.13 vs. 5.07 +/- 0.08 and 5.39 +/- 0.10, respectively). CONCLUSION: Three weeks of preoperative enteral administration of a synbiotic composition reduced peritonitis-induced acute lung injury in rats in a CLP model. 相似文献
1000.