全文获取类型
收费全文 | 13106篇 |
免费 | 1234篇 |
国内免费 | 19篇 |
专业分类
耳鼻咽喉 | 188篇 |
儿科学 | 304篇 |
妇产科学 | 173篇 |
基础医学 | 1802篇 |
口腔科学 | 395篇 |
临床医学 | 1404篇 |
内科学 | 2669篇 |
皮肤病学 | 193篇 |
神经病学 | 1148篇 |
特种医学 | 464篇 |
外科学 | 1720篇 |
综合类 | 248篇 |
一般理论 | 13篇 |
预防医学 | 1587篇 |
眼科学 | 356篇 |
药学 | 981篇 |
中国医学 | 21篇 |
肿瘤学 | 693篇 |
出版年
2022年 | 89篇 |
2021年 | 264篇 |
2020年 | 168篇 |
2019年 | 244篇 |
2018年 | 275篇 |
2017年 | 193篇 |
2016年 | 205篇 |
2015年 | 247篇 |
2014年 | 332篇 |
2013年 | 518篇 |
2012年 | 732篇 |
2011年 | 767篇 |
2010年 | 427篇 |
2009年 | 401篇 |
2008年 | 655篇 |
2007年 | 681篇 |
2006年 | 679篇 |
2005年 | 744篇 |
2004年 | 669篇 |
2003年 | 648篇 |
2002年 | 627篇 |
2001年 | 292篇 |
2000年 | 341篇 |
1999年 | 235篇 |
1998年 | 159篇 |
1997年 | 155篇 |
1996年 | 122篇 |
1995年 | 135篇 |
1994年 | 94篇 |
1993年 | 83篇 |
1992年 | 169篇 |
1991年 | 175篇 |
1990年 | 172篇 |
1989年 | 168篇 |
1988年 | 147篇 |
1987年 | 141篇 |
1986年 | 159篇 |
1985年 | 147篇 |
1984年 | 132篇 |
1983年 | 118篇 |
1982年 | 90篇 |
1981年 | 104篇 |
1980年 | 82篇 |
1979年 | 101篇 |
1978年 | 92篇 |
1976年 | 74篇 |
1975年 | 76篇 |
1974年 | 80篇 |
1973年 | 98篇 |
1972年 | 66篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
11.
Comparison of ThinPrep versus conventional smear cytopreparatory techniques for fine-needle aspiration specimens of head and neck masses. 总被引:2,自引:0,他引:2
Lloyd Ford Barry M Rasgon Raymond L Hilsinger Raul M Cruz Karen Axelsson Gregory J Rumore Thomas M Schmidtknecht Balaram Puligandla John Sawicki William Pshea 《Otolaryngology--head and neck surgery》2002,126(5):554-561
OBJECTIVES: Diagnostic accuracy of the ThinPrep process (Cytyc, Boxborough, MA) was compared with that of conventional (smear) cytopreparation for fine-needle aspiration (FNA) of head and neck masses. METHODS: In a prospective, randomized, single-blinded study, 209 patients served as their own controls and underwent 236 FNAs using ThinPrep and conventional (smear) cytopreparatory techniques. RESULTS: ThinPrep produced less air-drying artifact and less mechanical distortion than the conventional method. The conventional technique was diagnostic in 63% of samples; the ThinPrep technique was diagnostic in 55% of samples. When all results were combined, pathologists subjectively preferred the conventional technique but accepted use of ThinPrep as the only cytopreparatory technique for most head and neck masses. CONCLUSIONS: For adequately experienced cytopathologists, ThinPrep is acceptable for FNA of salivary masses, neck cysts, metastatic lymph nodes, and thyroid lesions. Conventional smear technique should be used for FNA of nonmetastatic lymphoid lesions. Use of ThinPrep can complement use of the conventional (smear) cytopreparatory technique when aspirate is nondiagnostic or bloody, when the patient has a blood-borne infectious disease, when the clinician is inexperienced, or when aspirate has entered the syringe. 相似文献
12.
13.
NTS fallout-induced multiple myeloma in Utah. 总被引:1,自引:0,他引:1
14.
Two boys born in September 1949 played on uranium mill tailings from about ages 8 to 12. One of these boys was diagnosed as having leukemia at age 15.5. The 226Ra body burden of the survivor was measured at age 38. The whole-body 226Ra content measured by counting in vivo was 0 +/- 17 Bq and independently by Rn breath analysis as 4.3 +/- 2.1 Bq. At the same time, a control subject with no known exposure to 226Ra, matched in age, height, and weight, was also measured. The whole-body content was estimated as 4 +/- 15 Bq and independently by Rn breath analysis as 5.5 +/- 3.7 Bq. The body burden of the control subject was not significantly different from that of the exposed person. The radiation dose to the marrow-free skeleton assuming a constant 226Ra:Ca ratio since birth was 0.49 and 1.33 mGy at ages 14 and 38, respectively. The radiation dose to the marrow-free skeleton assuming 226Ra intake only between ages 8 to 12 was 1.4 and 2.8 mGy at ages 14 and 38, respectively. The best estimate is the mean of these two estimates: 0.9 and 2.1 mGy at ages 14 and 38, respectively. The alpha-particle dose to the red marrow from 226Ra and its decay products was 0.05 mGy at age 14 and 0.10 mGy at age 38. Since no excess was found for the radium dial painters whose doses were much higher, the induction of leukemia by doses of this magnitude would seem quite unlikely. 相似文献
15.
16.
Gavin Wright 《ANZ journal of surgery》2005,75(11):952-952
17.
18.
Relaxin down-regulates renal fibroblast function and promotes matrix remodelling in vitro. 总被引:1,自引:0,他引:1
Rosemary Masterson Tim D Hewitson Kristen Kelynack Marina Martic Laura Parry Ross Bathgate Ian Darby Gavin Becker 《Nephrology, dialysis, transplantation》2004,19(3):544-552
BACKGROUND: Renal fibroblasts are important effector cells in tubulointerstitial fibrosis, with experimental antifibrotic strategies focusing on the functional down-regulation of these cells. Several experimental models of fibrosis have provided evidence for the effectiveness of the polypeptide hormone relaxin as a potential antifibrotic agent. This study was conducted to further elucidate the antifibrotic mechanisms of relaxin on renal fibroblasts in vitro. METHODS: Rat cortical fibroblasts were obtained from outgrowth culture of renal tissue isolated from kidneys 3 days post-unilateral ureteric obstruction and constituted 100% of cells studied. A relaxin radio-receptor assay was used to establish binding of relaxin to renal fibroblasts in vitro. Functional studies then examined the effects of H2 relaxin (0, 1, 10 and 100 ng/ml) on fibroblast kinetics, expression of alpha-smooth muscle actin (alpha-SMA), total collagen synthesis, collagenase production and collagen-I lattice contraction. CTGF mRNA expression was also measured by northern analysis. RESULTS: H2 relaxin bound with high affinity to rat renal fibroblasts, but receptor numbers were low. Consistent with its previously reported bimodal effect, transforming growth factor (TGF-beta 1) reduced fibroblast proliferation, an effect abrogated by H2 relaxin. Fibroblasts exposed to H2 relaxin (100 ng/ml) for 24 h demonstrated decreased immunostaining for alpha-SMA and reduced alpha-SMA protein expression compared with controls. There was a trend for a relaxin-mediated reduction in total collagen synthesis and alpha 1(I) mRNA expression with large dose-related increases in collagenase protein expression being observed. TGF-beta 1-stimulated collagen-I lattice contraction was significantly inhibited following co-incubation with 100 ng/ml relaxin. Incremental doses of H2 relaxin had no significant effect on CTGF mRNA expression. CONCLUSIONS: The findings of this study suggest that the antifibrotic effects of relaxin involve down-regulation of fibroblast activity, increase in collagenase synthesis and restructuring of collagen-I lattices, which are consistent with its known physiological role of matrix remodelling. Although there appears to be an interaction between TGF-beta 1 and H2 relaxin, this does not appear to involve a reduction in CTGF mRNA expression. 相似文献
19.
J L Kitzmiller L A Gavin G D Gin L Jovanovic-Peterson E K Main W D Zigrang 《JAMA》1991,265(6):731-736
To test the value of intensive management of diabetes before and during early pregnancy, 84 women recruited prior to conception were compared with 110 women who were already pregnant referred at 6 to 30 weeks' gestation. All underwent daily measurement of fasting and postprandial capillary blood glucose levels. Mean blood glucose levels during embryogenesis and organogenesis were within 3.3 to 7.8 mmol/L in 50% of preconception subjects and exceeded 10 mmol/L in 6.5%. One major congenital anomaly occurred in 84 infants (1.2%) of women treated before conception compared with 12 anomalies in 110 infants (10.9%) of mothers in the postconception group. Transient symptomatic hypoglycemia occurred during embryogenesis in 60% of women in the preconception group, with a median frequency of 2.7 episodes per week, but was not associated with excess malformations. We conclude that education and intensive management for glycemic control of diabetic women before and during early pregnancy will prevent excess rates of congenital anomalies in their infants. 相似文献
20.
Antibiotic prophylaxis and secondary haemorrhage following transurethral resection of the prostate: a prospective trial 总被引:2,自引:0,他引:2
One hundred and sixty-two patients were studied in a random double-blind controlled trial of co-trimoxazole to prevent secondary haemorrhage following transurethral resection of the prostate (TURP). There was a significant correlation between the incidence of post-operative urinary infection and secondary haemorrhage (P less than 0.05) but no difference between the incidence of bleeding in the treatment and placebo groups. Although infection may play a role in the development of secondary haemorrhage, co-trimoxazole for 10 days does not decrease the incidence of this complication. 相似文献