全文获取类型
收费全文 | 37646篇 |
免费 | 3936篇 |
国内免费 | 75篇 |
专业分类
耳鼻咽喉 | 482篇 |
儿科学 | 1117篇 |
妇产科学 | 766篇 |
基础医学 | 5394篇 |
口腔科学 | 1447篇 |
临床医学 | 4287篇 |
内科学 | 7506篇 |
皮肤病学 | 450篇 |
神经病学 | 2955篇 |
特种医学 | 1413篇 |
外国民族医学 | 2篇 |
外科学 | 5013篇 |
综合类 | 956篇 |
一般理论 | 30篇 |
预防医学 | 3928篇 |
眼科学 | 1044篇 |
药学 | 2841篇 |
1篇 | |
中国医学 | 29篇 |
肿瘤学 | 1996篇 |
出版年
2021年 | 535篇 |
2020年 | 342篇 |
2019年 | 558篇 |
2018年 | 643篇 |
2017年 | 488篇 |
2016年 | 509篇 |
2015年 | 631篇 |
2014年 | 878篇 |
2013年 | 1304篇 |
2012年 | 1707篇 |
2011年 | 1782篇 |
2010年 | 1009篇 |
2009年 | 1004篇 |
2008年 | 1567篇 |
2007年 | 1686篇 |
2006年 | 1551篇 |
2005年 | 1600篇 |
2004年 | 1459篇 |
2003年 | 1388篇 |
2002年 | 1369篇 |
2001年 | 1103篇 |
2000年 | 1158篇 |
1999年 | 1087篇 |
1998年 | 475篇 |
1997年 | 393篇 |
1996年 | 450篇 |
1995年 | 391篇 |
1994年 | 400篇 |
1993年 | 364篇 |
1992年 | 867篇 |
1991年 | 856篇 |
1990年 | 873篇 |
1989年 | 800篇 |
1988年 | 756篇 |
1987年 | 757篇 |
1986年 | 713篇 |
1985年 | 725篇 |
1984年 | 536篇 |
1983年 | 491篇 |
1982年 | 320篇 |
1981年 | 328篇 |
1980年 | 300篇 |
1979年 | 474篇 |
1978年 | 382篇 |
1977年 | 310篇 |
1976年 | 294篇 |
1974年 | 374篇 |
1973年 | 362篇 |
1972年 | 297篇 |
1971年 | 311篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
Four behavioural tests have been used to study the antinociceptive effects of electrical stimulation of the anterior pretectal nucleus (APtN) in the rat. The antinociceptive effects of stimulating this nucleus, which lies dorsally in the posterior diencephalon, have recently been studied extensively but always using briefly applied heat stimuli. It is reported here that APtN stimulation effectively inhibited responses to briefly applied noxious pressure and longer-lasting noxious chemical (formalin) stimuli. Although the tail-flick reflex to noxious heat was very potently depressed by APtN stimulation, responses to noxious heat in the hot-plate test were not. Three doses of morphine were also studied with each test and it was concluded that 15 sec of 35 microA r.m.s. current into the APtN was as effective as 3-5 mg/kg morphine s.c. in the rat. 相似文献
32.
33.
Factitious illness in children is a phenomenon that results in adverse consequences for the child. Munchausen by proxy is a factitious disorder, first described by Meadow (1977), in which a parent induces or creates the appearance of illness in the child. This article highlights the importance of social work skills in the identification and management of this syndrome, and proposes a format for decision making at various points in the process. 相似文献
34.
Sérgio Carreir?o Leandro Pereira Marcelo Wilson Rocha Almeida 《Aesthetic plastic surgery》2009,33(3):445-451
Surgical procedures for the mammary region currently are assuming an important role in body-contouring surgery. Enhancement
of results is a constant challenge to the plastic surgeon. A simple and efficient maneuver for resection of the breast’s lateral
pole based on the mammoplasty technique of Professor Ivo Pitanguy is described.
This study realized at the Private Clinic Sérgio Carreir?o, Rio de Janeiro, RJ, Brazil. 相似文献
35.
David H. Wilson Catherine R. Chittleborough Kerry Kirke Janet F. Grant Richard E. Ruffin 《Sozial- und Pr?ventivmedizin》2004,13(5):406-412
Objectives: Heavy smokers are a segment of the smoking population who are at increased risk of smoking-related morbidity and least likely to achieve cessation. This study identifies the impact of heavy smoking on quality of life by gender and describes the subpopulation for improved targeting.Methods: South Australian representative population data (n = 3010) was used to compare the health-related quality of life status of male and female heavy smokers as assessed by the SF-36. 相似文献
36.
A. Bogaards PhD H.J.C.M. Sterenborg B.C. Wilson 《Photodiagnosis and Photodynamic Therapy》2007,4(3):170-178
With the advent of molecular-targeted fluorescent markers, there is a renewed interest in fluorescence quantification methods that are based on continuous wave excitation and multi-spectral image acquisition. However, little is known about their in vivo quantification performance. We reviewed the performance of five selected methods by analytically describing these and varying input parameters of irradiance, excitation geometry, collection efficiency, autofluorescence, melanin content, blood volume, blood oxygenation and tissue scattering using optical properties representing those for human skin. We identified one method that corrects for variations in all parameters. This requires image acquisition before and after marker administration, under identical geometry. Hence, it is suited for applications where the site of interest can be relocated (e.g. anaesthetized animals and dermatology). For applications where relocation is not possible, we identified a second method where the uncertainty in the fluorescence signal was ±20%. Hence, use of these methods can substantially aid in vivo fluorescence quantification compared to use of the raw fluorescence signal, as this changed by more than 3 orders of magnitude. Since these methods can be computed in real-time, they are of particular interest for applications where direct feedback is critical, as diagnostic screening or image-guided surgery. 相似文献
37.
38.
N. I. L. Wilson 《The Journal of hospital infection》1987,9(3):235-242
The current use of methods, in Scotland, to prevent infection following orthopaedic surgery was established by postal questionnaire. Thirty-five per cent of surgeons used antibiotic cement routinely for total hip replacement. Ultraclean air facilities were provided for only 19%. Ninety-one per cent of surgeons used prophylactic parenteral antibiotics during total hip replacement, 75% in the management of open fractures, but only 12% for metal implants. Most chose an appropriate antibiotic. Only one-third of surgeons used an antibiotic regimen of appropriate duration and timing for total hip replacement or when employing metal implants. 相似文献
39.
Hallucinations and associated factors in Alzheimer's disease. 总被引:1,自引:0,他引:1
D W Gilley M E Whalen R S Wilson D A Bennett 《The Journal of neuropsychiatry and clinical neurosciences》1991,3(4):371-376
In a consecutive sample of 230 community-dwelling patients with probable Alzheimer's disease, a structured interview yielded evidence of current hallucinations in 29.1% and misperceptions in another 11.3%. Visual and auditory modalities were similarly represented in apparent hallucinations. Hallucinations prior to the current monitoring period were rare among patients with misperceptions or with no perceptual abnormality. The probability of hallucinations was associated with the severity of cognitive dysfunction, the degree of other behavioral disturbances, and the presence of extrapyramidal signs. A logistic regression model predicting hallucinations based on these diverse clinical features accurately classified 87.0% of the sample. 相似文献
40.
Non-clastogenicity in mouse bone marrow of fructose/lysine and other sugar/amino acid browning products with in vitro genotoxicity 总被引:1,自引:0,他引:1
J T MacGregor J D Tucker I I Ziderman C M Wehr R E Wilson M Friedman 《Food and chemical toxicology》1989,27(11):715-721
Heated sugar/amino acid reaction mixtures, known to contain products that are clastogenic and/or mutagenic to cells in vitro, were evaluated for clastogenic activity in mouse bone marrow using the erythrocyte micronucleus assay. Heated (i.e. browned) fructose/lysine reaction mixtures were also evaluated in the Salmonella his-reversion assay and the Chinese hamster ovary (CHO) cell chromosomal aberration assay to confirm and extend previous in vitro observations. Significant mutagenicity of fructose/lysine mixtures was observed in Salmonella typhimurium strains TA100, TA2637, TA98 and TA102, with greater activity in mixtures heated at pH 10 than at pH 7. S-9 decreased the activity in strains TA100, TA2637 and TA98, but increased the activity in strain TA102. Both pH 7 and pH 10 reaction mixtures of the fructose/lysine browning reaction were highly clastogenic in CHO cells. Heated mixtures of fructose and lysine, and of glucose or ribose with lysine, histidine, tryptophan or cysteine, did not increase the frequency of micronucleated erythrocytes in mice when administered by the oral route. This indicates the absence of chromosomal aberrations in erythrocyte precursor cells, and indicates that the genotoxic components of the browned mixtures are not absorbed and distributed to bone marrow cells in amounts sufficient to induce micronuclei when given orally. Because sugar/amino acid browning reactions occur commonly in heated foods, it is important to evaluate further the in vivo genotoxicity of browning products in cell populations other than bone marrow. 相似文献