全文获取类型
收费全文 | 6454篇 |
免费 | 493篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 39篇 |
儿科学 | 214篇 |
妇产科学 | 146篇 |
基础医学 | 640篇 |
口腔科学 | 122篇 |
临床医学 | 1007篇 |
内科学 | 1233篇 |
皮肤病学 | 41篇 |
神经病学 | 724篇 |
特种医学 | 431篇 |
外国民族医学 | 1篇 |
外科学 | 647篇 |
综合类 | 139篇 |
预防医学 | 559篇 |
眼科学 | 115篇 |
药学 | 477篇 |
中国医学 | 9篇 |
肿瘤学 | 409篇 |
出版年
2023年 | 42篇 |
2022年 | 59篇 |
2021年 | 168篇 |
2020年 | 92篇 |
2019年 | 157篇 |
2018年 | 158篇 |
2017年 | 123篇 |
2016年 | 121篇 |
2015年 | 129篇 |
2014年 | 203篇 |
2013年 | 290篇 |
2012年 | 377篇 |
2011年 | 434篇 |
2010年 | 212篇 |
2009年 | 190篇 |
2008年 | 323篇 |
2007年 | 354篇 |
2006年 | 349篇 |
2005年 | 282篇 |
2004年 | 289篇 |
2003年 | 255篇 |
2002年 | 247篇 |
2001年 | 172篇 |
2000年 | 152篇 |
1999年 | 117篇 |
1998年 | 60篇 |
1997年 | 41篇 |
1996年 | 54篇 |
1995年 | 51篇 |
1994年 | 54篇 |
1993年 | 29篇 |
1992年 | 97篇 |
1991年 | 106篇 |
1990年 | 106篇 |
1989年 | 104篇 |
1988年 | 84篇 |
1987年 | 71篇 |
1986年 | 92篇 |
1985年 | 84篇 |
1984年 | 64篇 |
1983年 | 46篇 |
1982年 | 38篇 |
1980年 | 31篇 |
1979年 | 49篇 |
1978年 | 39篇 |
1977年 | 29篇 |
1976年 | 38篇 |
1975年 | 28篇 |
1974年 | 29篇 |
1972年 | 28篇 |
排序方式: 共有6953条查询结果,搜索用时 15 毫秒
31.
H M Cheng O S Singh K K Kwong J Xiong B T Woods T J Brady 《Optometry and vision science》1992,69(9):698-701
We have obtained multislice magnetic resonance (MR) images of the eye and calculated ocular dimensions along the three cardinal axes: antero-posterior (A-P), equatorial, and vertical. We found no difference in the shape of hyperopic (average refractive error: +3.72 D) and emmetropic eyes, both of which had an equatorial diameter longer than the A-P and vertical diameters. Myopic eyes (average refractive error: -6.54 D) were larger than hyperopic eyes, and most had the same spheroelliptical shape as that of the emmetropic and hyperopic eyes. The results suggest that during myopic progression an overall enlargement or a radial volume expansion has occurred. 相似文献
32.
Molecular basis of essential fructosuria: molecular cloning and mutational analysis of human ketohexokinase (fructokinase) 总被引:2,自引:0,他引:2
Bonthron David T.; Brady Nlcola; Donaldson lain A.; Steinmann Beat 《Human molecular genetics》1994,3(9):1627-1631
Essential fructosuria is one of the oldest known inborn errorsof metabolism. It is a benign condition which is believed toresult from deficiency of hepatic fructokinase (ketohexokinase,KHK, E.C.2.7.1.3). This enzyme catalyses the first step of metabolismof dietary fructose, conversion of fructose to fructose-1-phosphate.Despite the early recognition of this disorder, the primarystructure of human KHK and the molecular basis of essentialfructosuria have not been previously defined. In this report,the isolation and sequencing of full-length cDNA clones encodinghuman ketohexokinase are described. Alternative mRNA speciesand alternative KHK isozymes are produced by alternative polyadenylationand splicing of the KHK gene. The KHK proteins show a high levelof sequence conservation relative to rat KHK. Direct evidencethat mutation of the KHK structural gene is the cause of essentialfructosuria was also obtained. In a well-characterized family,in which three of eight siblings have fructosurla, all affectedindividuals are compound heterozygotes for two mutations Gly40Argand Ala43Thr. Both mutations result from G 相似文献
33.
Dr. Mary S. Brady MD Carol F. Garfein MBA Jeanne A. Petrek MD Murray F. Brennan MD 《Annals of surgical oncology》1994,1(1):66-72
Background: Many patients treated for breast cancer with radiotherapy will survive their disease and be at risk for treatment-related sarcoma for many years.
Methods: In order to identify patients with post-treatment sarcoma and define this disease, we examined the records of 99 patients treated for sarcoma with a history of antecedent breast carcinoma. Of these patients, 51 were felt to have a sarcoma unrelated to breast cancer treatment and 48 were felt to have a treatment-related sarcoma (secondary to lymphedema and/or radiation).
Results: Lymphangiosarcoma of the extremity was the most common histologic subtype of post-treatment sarcoma, accounting for 22 of 48 cases (46%). Twenty-six patients (54%) developed nonlymphangiosarcoma post-treatment sarcoma; all of these were radiation-associated sarcomas. The median latency interval between the diagnosis of breast cancer and the development of sarcoma was 11 years (range 4–44) and was not different between the two groups. However, patients with nonlymphangiosarcoma were significantly younger when diagnosed with breast cancer than were those with lymphangiosarcoma of the extremity (median 43 vs. 51 years, p<0.001). The survival of all 48 patients was poor: 5-year survival was 29%. Five-year survival of patients with other types of post-treatment sarcoma was just as poor as those with lymphangiosarcoma of the extremity (30% vs. 28%, p=0.98).
Conclusions: Patients who develop sarcoma after treatment for breast cancer have a poor prognosis whether it occurs as Stewart-Treves syndrome or other types of post-treatment sarcoma. Younger patients may be at higher risk than are older patients for the development of nonlymphangiosarcoma post-treatment sarcoma.Presented at the 46th Annual Cancer Symposium of the Society of Surgical Oncology, Los Angeles, March 18–21, 1993. 相似文献
34.
Y. H. K. Lodhi R. Kingston O. Brady 《European journal of orthopaedic surgery & traumatology : orthopedie traumatologie》2007,17(2):199-201
Compression of median nerve at elbow secondary to loose body is very rare, only two cases have been reported in literature. Elbow swelling in this case led us to the cause of our patient’s median nerve dysfunction. A simple day case elbow arthroscopy procedure, and removal of loose body provided a cure for the elbow symptoms and the neuropathy. Compression neuropathy at the elbow, while rare, should be considered in the differential diagnosis of hand paraesthesia. 相似文献
35.
Dynamic imaging with lanthanide chelates in normal brain: contrast due to magnetic susceptibility effects 总被引:22,自引:0,他引:22
A Villringer B R Rosen J W Belliveau J L Ackerman R B Lauffer R B Buxton Y S Chao V J Wedeen T J Brady 《Magnetic resonance in medicine》1988,6(2):164-174
Using a one-dimensional rapid imaging technique, we have found that injection of lanthanide chelates such as Gd(DTPA)2- leads to a significant decrease (50%) in rat brain signal intensity at 1.45 T using T2-weighted pulse sequences; however, no effect of comparable size is observed with T1-weighted pulse sequences. The transient effect and its kinetics were followed with a temporal resolution of between 1 and 8 s. Experiments with different lanthanide chelates show that the observed decrease in signal intensity correlates with the magnetic moment of each agent but not with their longitudinal relaxivity. Three-dimensional chemical-shift resolved experiments demonstrate significant line broadening in brain during infusion with Dy(DTPA)2-. Our results show that the cause of this effect is the difference in susceptibility between the capillaries, containing the contrast agent, and the surrounding tissue. As a result of these susceptibility differences, field gradients are produced in the tissue and diffusion of water through these gradients leads to a loss of spin phase coherence and thus a decrease in signal intensity. We propose this as a new type of contrast agent mechanism in NMR. The effect and its kinetics are likely to be related to important physiological parameters such as cerebral blood volume and cerebral blood flow, and do not depend on a breakdown of the blood-brain barrier as do conventional contrast agent techniques. 相似文献
36.
37.
Robert D. Hienz Troy J. Zarcone Danielle A. Pyle Joseph V. Brady 《Psychopharmacology》1997,134(1):38-45
The effects of cocaine and quinpirole were studied in baboons to determine whether quinpirole, a relatively selective D2/D3 dopamine agonist, produced effects similar to those of cocaine on perceptual and motor processes. To measure perceptual and
motor function, three baboons were trained to discriminate differences between a standard vowel and four other synthetic vowels;
response accuracy as well as response latencies, or ”reaction times”, were measured following drug administrations. Cocaine
reduced reaction times in two baboons, and did not affect reaction times in a third; on the other hand, quinpirole lengthened
reaction times in a dose-dependent manner in all baboons. Cocaine and quinpirole also differed in the time course to produce
the maximal reaction time effect following drug administration. Cocaine and quinpirole did not differ consistently in their
perceptual effects, as indicated by similar changes in d′, a signal-detection index of discriminability. These distinct profiles of effects for cocaine and quinpirole suggest differing
neurochemical actions for these two drugs.
Received: 10 August 1996 /Final version: 16 May 1997 相似文献
38.
39.
We describe a case of an infant with complete congenital absence of the extraocular muscles, noted at surgery and confirmed by multiplane MR, which found no evidence of extraocular muscle tissue. This almost certainly represents an extreme form of bilateral congenital fibrosis syndrome. 相似文献
40.
Rupture of an intra-aortic balloon counterpulsator (IABCP) demands immediate removal. We report a case of thrombus formation within a Datascope IABCP secondary to IABCP rupture, necessitating surgical exploration for removal. There is a disturbing pattern of balloon ruptures with this type of IABCP. 相似文献