全文获取类型
收费全文 | 2457篇 |
免费 | 131篇 |
国内免费 | 28篇 |
专业分类
耳鼻咽喉 | 80篇 |
儿科学 | 143篇 |
妇产科学 | 110篇 |
基础医学 | 171篇 |
口腔科学 | 100篇 |
临床医学 | 228篇 |
内科学 | 621篇 |
皮肤病学 | 53篇 |
神经病学 | 140篇 |
特种医学 | 69篇 |
外科学 | 550篇 |
综合类 | 38篇 |
预防医学 | 62篇 |
眼科学 | 92篇 |
药学 | 72篇 |
中国医学 | 2篇 |
肿瘤学 | 85篇 |
出版年
2024年 | 1篇 |
2023年 | 13篇 |
2022年 | 19篇 |
2021年 | 54篇 |
2020年 | 40篇 |
2019年 | 56篇 |
2018年 | 71篇 |
2017年 | 57篇 |
2016年 | 94篇 |
2015年 | 137篇 |
2014年 | 121篇 |
2013年 | 144篇 |
2012年 | 208篇 |
2011年 | 203篇 |
2010年 | 123篇 |
2009年 | 100篇 |
2008年 | 193篇 |
2007年 | 207篇 |
2006年 | 169篇 |
2005年 | 177篇 |
2004年 | 149篇 |
2003年 | 90篇 |
2002年 | 65篇 |
2001年 | 18篇 |
2000年 | 16篇 |
1999年 | 11篇 |
1998年 | 8篇 |
1997年 | 7篇 |
1996年 | 4篇 |
1995年 | 3篇 |
1994年 | 3篇 |
1993年 | 4篇 |
1992年 | 11篇 |
1991年 | 5篇 |
1990年 | 3篇 |
1989年 | 4篇 |
1988年 | 2篇 |
1987年 | 4篇 |
1986年 | 1篇 |
1984年 | 5篇 |
1983年 | 2篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 3篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1975年 | 2篇 |
1974年 | 1篇 |
1972年 | 2篇 |
1970年 | 1篇 |
排序方式: 共有2616条查询结果,搜索用时 343 毫秒
91.
The aim of this prospective experimental study was to evaluate the effect of light-emitting diode (LED) photobiomodulation therapy (LPT) on the stability of immediately loaded miniscrews under different force levels, as assessed by resonance frequency analysis (RFA). Sixty titanium orthodontic miniscrews with a length of 8 mm and a diameter of 1.4 mm were implanted into cortical bone by closed flap technique in each proximal tibia of 15 New Zealand white adult male rabbits (n = 30). The animals were randomly divided into irradiated and control groups under different force levels (0, 150, and 300 cN). OsseoPulse? LED device (Biolux Research Ltd.) 618 nm wavelength and 20 mW/cm(2) output power irradiation (20 minutes/day) was applied to the miniscrews for 10 days. The RFA records were performed at miniscrew insertion session (T1) and 21 days after surgery (T2). Wilcoxon and Mann-Whitney U-tests were used for statistical evaluation at P < 0.005 level. It was found that initial primer stability of all miniscrews was similar in all groups at the start of the experimental procedure. Statistically significant differences were found for changes in implant stability quotient (ISQ) values between LED-photobiomodulated group and the control (0 cN, P = 0.001; 150 cN, P < 0.001; and 300 cN, P < 0.001). Significant increase was found in ISQ values of LPT applied miniscrews under 0 cN (+11.63 ISQ), 150 cN (+10.50 ISQ), and 300 cN (+7.00 ISQ) force during observation period. By the increase of force levels, it was determined that ISQ values decreased in non-irradiated control miniscrews. Within the limits of this in vivo study, the present RFA findings suggest that LPT might have a favourable effect on healing and attachment of titanium orthodontic miniscrews. 相似文献
92.
93.
Huseyin Istanbullu Gulsah Bayraktar Hasan Akbaba Ibrahim Cavus Gunes Coban Bilge Debelec Butuner Ali Ahmet Kilimcioglu Ahmet Ozbilgin Vildan Alptuzun Ercin Erciyas 《Archiv der Pharmazie》2020,353(8):1900325
A series of thiazolopyrimidine derivatives was designed and synthesized as a Leishmania major pteridine reductase 1 (LmPTR1) enzyme inhibitor. Their LmPTR1 inhibitor activities were evaluated using the enzyme produced by Escherichia coli in a recombinant way. The antileishmanial activity of the selected compounds was tested in vitro against Leishmania sp. Additionally, the compounds were evaluated for cytotoxic activity against the murine macrophage cell line RAW 264.7. According to the results, four compounds displayed not only a potent in vitro antileishmanial activity against promastigote forms but also low cytotoxicity. Among them, compound L16 exhibited an antileishmanial activity for both the promastigote and amastigote forms of L. tropica, with IC50 values of 7.5 and 2.69 µM, respectively. In addition, molecular docking studies and molecular dynamics simulations were also carried out in this study. In light of these findings, the compounds provide a new potential scaffold for antileishmanial drug discovery. 相似文献
94.
Nigar Yilmaz Yasemin Ustundag Seyda Kivrak Serdar Kahvecioglu Huseyin Celik Ibrahim Kivrak 《Renal failure》2016,38(8):1300-1309
Background: The level and activity of indoleamine 2,3-dioxygenase (IDO) and the concentrations of L-tryptophan and its metabolite L-kynurenine were determined in association with various renal diseases. However, there have been no data regarding these parameters in patients on peritoneal dialysis compared to those undergoing hemodialysis or kidney transplantation.Methods: This study investigated the level and activity of IDO and determined oxidative balance by calculating the total oxidant status (TOS), total antioxidant status (TAS), and oxidative stress index (OSI). We enrolled 60 kidney disease patients, including 20 on peritoneal dialysis (PD group), 19 on hemodialysis (HD group), and 21 with kidney transplantation (KT group), as well as 21 control group.Results: IDO levels were increased in the PD, HD, and KT groups compared to the control group. The concentration of kynurenine was significantly increased in the PD group compared to the other groups (p?0.01). The kynurenine/tryptophan ratio was increased in the PD group compared to the other groups (all p?0.01). TAS levels in the PD and HD groups were significantly decreased compared to the control group (both p?0.05). TAS levels in the PD group were significantly decreased compared to the KT group. TOS levels in the PD group were higher than in the HD and KT groups.Conclusion: The results showed that IDO levels were increased in peritoneal dialysis and hemodialysis patients and in renal transplant recipients, while oxidative stress was found to be related to IDO activity and was most increased in the patients on peritoneal dialysis. 相似文献
95.
96.
Melih Velipasaoglu Reyhan Ayaz Metin Senturk Samet Arslan Huseyin Mete Tanir 《The journal of maternal-fetal & neonatal medicine》2016,29(23):3838-3842
Objectives: This prospective, randomized study aimed to compare the analgesic effects of acetaminophen, diclofenac and hyoscine-N-butylbromide (HnBB) in cases of second trimester pregnancy termination.Methods: In 60 women with indications for second trimester pregnancy termination, three analgesic agents were randomized into three groups: group 1, acetaminophen; group 2, diclofenac; and group 3, HnBB. A visual analog scale (VAS) used for the evaluation of pain perception. The primary outcome of the study was mean VAS score during the procedure and last VAS score before the completion of termination. The secondary outcomes were the induction-to-abortion interval, the percentage of aborted cases within the first 24?h and finally the need for parenteral analgesia.Results: Demographic characteristics were similar among the groups. The mean VAS and last VAS scores before termination did not differ among the groups (p?=?0.3 and 0.2, respectively). The need for parenteral analgesia did not differ among the groups (p?=?0.3). Although a shorter induction-to-abortion interval and greater number of cases with successful termination before 24?h were found in the HnBB group, the differences were not statistically significant (p?=?0.6 and 0.5, respectively).Conclusions: Our study did not demonstrate a difference in pain perception among second trimester pregnancy termination cases using acetaminophen, diclofenac and HnBB. 相似文献
97.
98.
99.