全文获取类型
收费全文 | 4109篇 |
免费 | 280篇 |
国内免费 | 12篇 |
专业分类
耳鼻咽喉 | 92篇 |
儿科学 | 254篇 |
妇产科学 | 150篇 |
基础医学 | 453篇 |
口腔科学 | 104篇 |
临床医学 | 441篇 |
内科学 | 723篇 |
皮肤病学 | 102篇 |
神经病学 | 347篇 |
特种医学 | 164篇 |
外科学 | 592篇 |
综合类 | 52篇 |
一般理论 | 1篇 |
预防医学 | 347篇 |
眼科学 | 112篇 |
药学 | 233篇 |
中国医学 | 3篇 |
肿瘤学 | 231篇 |
出版年
2024年 | 3篇 |
2023年 | 42篇 |
2022年 | 75篇 |
2021年 | 147篇 |
2020年 | 77篇 |
2019年 | 151篇 |
2018年 | 157篇 |
2017年 | 139篇 |
2016年 | 133篇 |
2015年 | 179篇 |
2014年 | 214篇 |
2013年 | 291篇 |
2012年 | 356篇 |
2011年 | 330篇 |
2010年 | 198篇 |
2009年 | 132篇 |
2008年 | 275篇 |
2007年 | 260篇 |
2006年 | 226篇 |
2005年 | 219篇 |
2004年 | 200篇 |
2003年 | 166篇 |
2002年 | 140篇 |
2001年 | 45篇 |
2000年 | 33篇 |
1999年 | 40篇 |
1998年 | 16篇 |
1997年 | 17篇 |
1996年 | 16篇 |
1995年 | 9篇 |
1994年 | 6篇 |
1993年 | 9篇 |
1992年 | 12篇 |
1991年 | 10篇 |
1990年 | 7篇 |
1989年 | 6篇 |
1988年 | 4篇 |
1987年 | 4篇 |
1986年 | 5篇 |
1985年 | 6篇 |
1984年 | 7篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1981年 | 3篇 |
1980年 | 4篇 |
1979年 | 3篇 |
1978年 | 4篇 |
1977年 | 3篇 |
1954年 | 2篇 |
1952年 | 2篇 |
排序方式: 共有4401条查询结果,搜索用时 0 毫秒
71.
Tevfik Yavuz Erhan Dilber Haluk Baris Kara Ali Riza Tuncdemir A Nilgun Ozturk 《Lasers in medical science》2013,28(5):1233-1239
The purpose of this study was to evaluate the influence of different surface treatments (sandblasting, acid etching, and laser irradiation) on the shear bond strength of lithium disilicate-based core (IPS Empress 2) and feldspathic ceramics (VITA VM 9). One hundred ceramic discs were divided into two groups of 50 discs each for two ceramic systems: IPS Empress 2 (group I) and VITA VM 9 (group II). Each of the two groups was further divided into five surface treatment groups (ten each) as follows: group SB, sandblasting with alumina particles (50 μm); group HF, 5 % hydrofluoric acid etching; group L, Er:YAG laser irradiation (distance, 1 mm; 500 mJ; 20 Hz; 10 W; manually, noncontact R14 handpiece); group SB–L, sandblasting + Er:YAG laser; and group HF–L, 5 % hydrofluoric acid + Er:YAG laser. Luting cement (Panavia 2.0) was bonded to the ceramic specimens using Teflon tubes. After 24 h of water storage, a shear bond strength test was performed using a universal testing machine at a crosshead speed of 0.5 mm/min. The data were analyzed with a two-way analysis of variance (ANOVA) and Tukey's honestly significant difference tests (α?=?0.05). The two-way ANOVA indicated that the shear bond strength was significantly affected by the surface treatment methods (p?<?0.05), but there was no significant interaction between the ceramic systems. Group SB–L had the highest mean values for each ceramic system. Sandblasting, followed by Er:YAG laser irradiation, enhanced the bond strength, indicating its potential use as an alternative method. The atomic force microscopic evaluation revealed that group SB had the most distinct sharp peaks among the groups. 相似文献
72.
73.
74.
75.
76.
Christopher M. Jack William L. Walter Andrew J. Shimmin Kara Cashman Richard N. de Steiger 《The Journal of arthroplasty》2013
The use of large diameter metal bearing total hip arthroplasty (THA) and hip resurfacing arthroplasty (HRA) increased in popularity in the last decade. More recent literature has highlighted the effect of head size in patient outcomes. Data was obtained from the Australian Orthopaedic Association National Joint Replacement Registry (AOA-NJRR) to evaluate the Birmingham (MoM) bearing surface when used with THA and HRA. There is no difference in the overall rate of revision between the THA and HRA but head size has a significant effect on revision rate. The data show that small diameter metal bearings in HRA (below 50 mm) have a higher rate of revision than large diameter metal bearings in HRA (equal to and above 50 mm) (P < .001). Conversely the large diameter metal bearings in THA have a higher rate of revision than the small diameter metal bearings in THA (P = .027). The revision rate for large diameter HRA compared to small diameter THA is not significantly different P = .670. We recommend caution when choosing either a large diameter (≥ 50 mm) metal on metal THA or small diameter (< 50 mm) HRA. 相似文献
77.
Godwin G.H. Choy John A. Roe Sarah L. Whitehouse Kara S. Cashman Ross W. Crawford 《The Journal of arthroplasty》2013
The standard Exeter stem has a length of 150 mm with offsets 37.5 to 56 mm. Shorter stems of lengths 95, 115 and 125 mm with offsets 35.5 mm or less are available for patients with smaller femurs. Concern has been raised regarding the behavior of the smaller implants. This paper analyzed data from the Australian Orthopaedic Association National Joint Replacement Registry comparing survivorship of stems of offset 35.5 mm or less with the standard stems of 37.5 mm offset or greater. At 7 years, there was no significant difference in the cumulative percent revision rate in the short stems (3.4%, 95% CI 2.4-4.8%) compared with the standard length stems (3.5%, 95% CI 3.3-3.8%) despite its use in a greater proportion of potentially more difficult developmental dysplasia of the hip cases. 相似文献
78.
Hasan Kayabasi Ali Kemal Kadiroglu Ismail Hamdi Kara Mehmet Emin Yilmaz 《Renal failure》2013,35(5):513-519
Tuberculosis remains a significant health problem for patients receiving chronic dialysis. The purpose of this study was to evaluate the prevalence, clinical characteristics, and outcomes of tuberculosis among patients with end-stage renal failure (ESRF) undergoing chronic hemodialysis and continuous ambulatory peritoneal dialysis. Between 1999 and 2006, we diagnosed 21 active tuberculosis patients among a total of 674-dialysis patient in our dialysis center (582 patients on hemodialysis and 92 patients on continuous ambulatory peritoneal dialysis program). Fourteen patients developed extrapulmonary tuberculosis (generally tuberculous lymphadenitis, n = 8) and seven patients developed pulmonary tuberculosis. All patients who developed tuberculosis after starting dialysis had low creatinine clearances and, in general, anemia and hypoalbuminemia. Three of patients greater than 40 years died. In conclusion, tuberculous lymphadenitis was the most frequent form of extrapulmonary tuberculosis in our dialysis population. If no cause is found despite extensive investigations in an end stage renal failure case with fever, loss of weight, and/or atypical lymphadenopathy, the physician should consider the possibility of tuberculosis. Finally, it was considered that ESRF is associated with depressed immune system and elevated risk of tuberculosis; thus, in this population, clinicians must evaluate patients carefully. 相似文献
79.
Sean C. Skeldon Kara Semotiuk Melyssa Aronson Spring Holter Steven Gallinger Aaron Pollett Cynthia Kuk Bas van Rhijn Peter Bostrom Zane Cohen Neil E. Fleshner Michael A. Jewett Sally Hanna Shahrokh F. Shariat Theodorus H. Van Der Kwast Andrew Evans Jim Catto Bharati Bapat Alexandre R. Zlotta 《European urology》2013
Background
Lynch syndrome (LS), or hereditary nonpolyposis colorectal cancer, is caused by mutations in mismatch repair (MMR) genes. An increased risk for upper tract urothelial carcinoma (UTUC) has been described in this population; however, data regarding the risk for bladder cancer (BCa) are sparse.Objective
To assess the risk of BCa in MMR mutation carriers and suggest screening and management recommendations.Design, setting, and participants
Cancer data from 1980 to 2007 were obtained from the Familial Gastrointestinal Cancer Registry in Toronto for 321 persons with known MMR mutations: mutL homolog 1, colon cancer, nonpolyposis type 2 (E. coli) (MLH1); mutS homolog 2, colon cancer, nonpolyposis type 1 (E. coli) (MSH2); mutS homolog 6 (E. coli) (MSH6); and PMS2 postmeiotic segregation increased 2 (S. cerevisiae) (PMS2).Outcome measurements and statistical analysis
Standardized incidence ratios from the Ontario Cancer Registry, using the Surveillance Epidemiology and End Results public database, were used to compare cancer risk in patients with MMR mutations with the Canadian population. Microsatellite instability analysis and immunohistochemistry (IHC) of the MMR proteins were also performed and the results compared with matched sporadic bladder tumors.Results and limitations
Eleven of 177 patients with MSH2 mutations (6.21%, p < 0.001 compared with the Canadian population) were found to have BCa, compared with 3 of 129 patients with MLH1 mutations (2.32%, p > 0.05). Of these 11 tumors, 81.8% lacked expression of MSH2 on IHC, compared with the matched sporadic cases, which all displayed normal expression of MSH2 and MLH1. The incidence of UTUC among MSH2 carriers was 3.95% (p < 0.001), and all tumors were found to be deficient in MSH2 expression on IHC. Mutations in the intron 5 splice site and exon 7 of the MSH2 gene increased the risk of urothelial cancer. Limitations include possible inflated risk estimates due to ascertainment bias.Conclusions
LS patients with MSH2 mutations are at an increased risk for not only UTUC but also BCa and could be offered appropriate screening. 相似文献80.
Omental patch repair effectively treats perforated marginal ulcer following Roux-en-Y gastric bypass
Mark R. Wendling John G. Linn Kara M. Keplinger Dean J. Mikami Kyle A. Perry W. Scott Melvin Bradley J. Needleman 《Surgical endoscopy》2013,27(2):384-389