全文获取类型
收费全文 | 8613篇 |
免费 | 588篇 |
国内免费 | 89篇 |
专业分类
耳鼻咽喉 | 106篇 |
儿科学 | 295篇 |
妇产科学 | 291篇 |
基础医学 | 929篇 |
口腔科学 | 159篇 |
临床医学 | 928篇 |
内科学 | 1862篇 |
皮肤病学 | 215篇 |
神经病学 | 860篇 |
特种医学 | 227篇 |
外科学 | 1403篇 |
综合类 | 166篇 |
一般理论 | 3篇 |
预防医学 | 421篇 |
眼科学 | 136篇 |
药学 | 642篇 |
中国医学 | 70篇 |
肿瘤学 | 577篇 |
出版年
2023年 | 43篇 |
2022年 | 101篇 |
2021年 | 218篇 |
2020年 | 105篇 |
2019年 | 196篇 |
2018年 | 234篇 |
2017年 | 165篇 |
2016年 | 186篇 |
2015年 | 253篇 |
2014年 | 312篇 |
2013年 | 433篇 |
2012年 | 559篇 |
2011年 | 624篇 |
2010年 | 376篇 |
2009年 | 354篇 |
2008年 | 518篇 |
2007年 | 504篇 |
2006年 | 521篇 |
2005年 | 460篇 |
2004年 | 446篇 |
2003年 | 326篇 |
2002年 | 309篇 |
2001年 | 275篇 |
2000年 | 216篇 |
1999年 | 217篇 |
1998年 | 59篇 |
1997年 | 60篇 |
1996年 | 54篇 |
1995年 | 33篇 |
1994年 | 45篇 |
1993年 | 44篇 |
1992年 | 100篇 |
1991年 | 102篇 |
1990年 | 104篇 |
1989年 | 97篇 |
1988年 | 80篇 |
1987年 | 71篇 |
1986年 | 58篇 |
1985年 | 56篇 |
1984年 | 54篇 |
1983年 | 37篇 |
1982年 | 16篇 |
1981年 | 25篇 |
1980年 | 20篇 |
1979年 | 40篇 |
1978年 | 23篇 |
1977年 | 20篇 |
1976年 | 23篇 |
1975年 | 19篇 |
1974年 | 23篇 |
排序方式: 共有9290条查询结果,搜索用时 15 毫秒
71.
Teh-Ying Chou Chao-Hua Chiu Ling-Hui Li Chun-Yen Hsiao Chin-Yuan Tzen Kuo-Ting Chang Yuh-Min Chen Reury-Perng Perng Shih-Feng Tsai Chun-Ming Tsai 《Clinical cancer research》2005,11(10):3750-3757
PURPOSE: Mutations in epidermal growth factor receptor (EGFR) can be used to predict the tumor response of patients receiving gefitinib for non-small cell lung cancer (NSCLC). We investigated the association between mutations in EGFR tyrosine kinase domain and tumor response and survival in gefitinib-treated NSCLC patients. EXPERIMENTAL DESIGN: EGFR mutations in exons 18 to 21 were analyzed by DNA sequencing of paraffin-embedded tumor tissues from gefitinib-treated NSCLC patients. The results were correlated with clinical variables. RESULTS: EGFR mutations were found in 61.1% (33 of 54) of cases; response rate and disease control rate were 56.8% and 68.5%, respectively. There was no significant difference in mutation rates between adenocarcinoma (29 of 43) and nonadenocarcinoma (4 of 11; P = 0.085). However, all four nonadenocarcinomas with EGFR mutations had no response to gefitinib. Presence of EGFR mutations was the only independent predictor for disease control (P = 0.003) and tumor response (P = 0.017) in multivariate analysis; positive predictive values were 87.9% and 70.8% and negative predictive values were 61.9% and 69.2%, respectively. In comparison with patients whose tumor was negative for EGFR mutations, patients with EGFR mutations had better progression-free survival (median, 7.6 versus 1.7 months; P = 0.011) and overall survival (median, 14.7 versus 4.7 months; P = 0.046). CONCLUSIONS: Mutations in EGFR tyrosine kinase correlate with treatment response and survival in gefitinib-treated NSCLC patients and can be used as a predictive and prognostic factor. Thus, analysis of EGFR tyrosine kinase mutations in lung adenocarcinoma is of clinical significance, as it can permit the customization of treatment with EGFR tyrosine kinase inhibitors. 相似文献
72.
Hwang CH Lin YL Liu YK Chen CH Wu HY Chang CC Chang CY Chang YK Chiu YH Liao KW Lai YK 《Phytotherapy research : PTR》2012,26(4):528-534
7,7'-Dimethoxyagastisflavone (DMGF), a biflavonoid isolated from the needles of Taxus × media cv. Hicksii, was evaluated for its antiproliferative and antineoplastic effects in three human cancer cell lines. Interestingly, DMGF caused cell death via different pathways in different cancer cells. DMGF induced apoptosis, activated caspase-3 activity and changed the mitochondrial membrane potential in HT-29 human colon cancer cells. However, the apoptotic pathway is not the major pathway involved in DMGF-induced cell death in A549 human lung cancer cells and HepG2 human hepatoma cells. Treatment with 3-MA, an inhibitor of autophagy, significantly decreased DMGF-induced cell death in HepG2 and A549 cells, but did not affect DMGF-induced cell death in HT-29 cells. Following DMGF treatment, the HepG2 cells increased expression of LC3B-II, a marker used to monitor autophagy in cells. Thus, DMGF induced apoptotic cell death in HT-29 cells, triggered both apoptotic and autophagic death in A549 cells and induced autophagic cell death in HepG2 cells. 相似文献
73.
Introduction:Traumatic testicular dislocation is an uncommon complication of blunt scrotal injury and is easily overlooked because of the presence of other severe accompanying injuries. In most cases, an operation is needed for the prevention of malignant change or infertility.Patient concerns and diagnosis:We report a case of traumatic testicular dislocation with pelvic fracture and internal bleeding in a 27-year-old male with testis rupture after a motorcycle collision.Interventions and outcomes:He received emergent right radical orchiectomy, and a series of operations for femoral and pelvic fractures were performed after his condition stabilized in the intensive care unit. After 1 month postsurgery, no obvious genitourinary complications were noted.Conclusion:We suggest scrotum examination in all trauma patients, particularly if a pelvic injury is suspected or in case of a high risk of a motorcycle collision, to avoid missing the diagnosis and prevent severe complications 相似文献
74.
75.
Desloratadine (descarboethoxyloratadine, CAS 100643-71-8) is a selective histamine H1 antagonist that exhibits qualitatively similar pharmacodynamic activity to its parent, loratadine (CAS 79794-75-5), but is 2.5-4 times more potent orally. In studies of central nervous system (CNS) effects that might lead to sedation, desloratadine had no behavioral, neurological or autonomic effects in the conscious mouse and rat. At large multiples of the antihistaminic dose in the mouse, it did not inhibit convulsions caused by electroconvulsive shock and inhibited acetic acid-induced writhing only at a dose approximately 1,000 times the antihistaminic dose in the mouse. Desloratadine had no effects on blood pressure, heart rate or electrocardiographic parameters in the rat or guinea pig or on electrocardiographic parameters in the monkey. Notably, there was no effect on the corrected Q-wave to T-wave (QTc) interval. Desloratadine did not inhibit IKr channel human ether-a-go-go-related gene (HERG)-induced current in a study in which HERG was expressed in Xenopus oocytes. In the rat, desloratadine did not cause effects in urine volume, electrolytes or creatinine, or inhibit gastric emptying or intestinal transit, or cause any harmful effects on gastric mucosa. The results of these preclinical studies provide evidence that desloratadine is a safe antihistamine without CNS or cardiovascular effects. 相似文献
76.
77.
Huili Li Katherine B. Chiappinelli Angela A. Guzzetta Hariharan Easwaran Ray-Whay Chiu Yen Rajita Vatapalli Michael J. Topper Jianjun Luo Roisin M. Connolly Nilofer S. Azad Vered Stearns Drew M. Pardoll Nancy Davidson Peter A. Jones Dennis J. Slamon Stephen B. Baylin Cynthia A. Zahnow Nita Ahuja 《Oncotarget》2014,5(3):587-598
Epigenetic therapy is emerging as a potential therapy for solid tumors. To investigate its mechanism of action, we performed integrative expression and methylation analysis of 63 cancer cell lines (breast, colorectal, and ovarian) after treatment with the DNA methyltransferase inhibitor 5-azacitidine (AZA). Gene Set Enrichment Analysis demonstrated significant enrichment for immunomodulatory pathways in all three cancers (14.4-31.3%) including interferon signaling, antigen processing and presentation, and cytokines/chemokines. Strong upregulation of cancer testis antigens was also observed. An AZA IMmune gene set (AIMs) derived from the union of these immunomodulatory pathway genes classified primary tumors from all three types into “high” and “low” AIM gene expression subsets in tumor expression data from both TCGA and GEO. Samples from selected patient biopsies showed upregulation of AIM genes after treatment with epigenetic therapy. These results point to a broad immune stimulatory role for DNA demethylating drugs in multiple cancers. 相似文献
78.
Seven new compounds, O-trans-cinnamoylglutinol (1), 22β-hydroxy-12-oleanen-3-one (2), 15α,16α-epoxy-12-oleanen-3-one (3), 29-hydroxy-12-oleanene-3,22-dione (4), 22β,29-dihyroxy-12-oleanen-3-one (5), 2,3-(methylenedioxy)-4-methoxy-5-methylphenol (8), and 2,3,6-trimethoxy-5-methylphenol (9), as well as two first isolated from natural sources, 25-cycloartene-3,24-dione (6) and 24ξ-hydroxy-25-cycloarten-3-one (7), were characterized from Derris laxiflora. The structures of these compounds were determined by analysis of their spectroscopic data. 相似文献
79.
Postnatal management and long-term outcome for survivors with congenital diaphragmatic hernia 总被引:1,自引:0,他引:1
Significant advances in the postnatal management of patients with congenital diaphragmatic hernia (CDH) have resulted in a remarkable improvement in survival rates over the past two decades. The success of current postnatal management of CDH patients has rendered fetal intervention to be limited to the most severe cases, and the role for prenatal treatment of CDH patients remains unclear. The adoption of lung-preserving strategies including high-frequency oscillatory ventilation (HFOV) and extracorporeal membrane oxygenation (ECMO) have improved CDH outcomes especially in those patients with significant ventilatory or circulatory compromise. Survival rates of up to 90% are being reported in some high-volume centers. However, the increased survival in CDH patients has been accompanied by an increase in neurological, nutritional and musculoskeletal morbidity among the long-term survivors. This has resulted in the need to provide resources for the long-term follow-up and support of this patient population. In this article, the postnatal management strategies and primary and secondary outcomes of high-volume international pediatric surgical centers will be reviewed. Finally, the role of a multidisciplinary management team for the follow-up of long-term CDH survivors will be discussed. 相似文献
80.