全文获取类型
收费全文 | 1927篇 |
免费 | 112篇 |
国内免费 | 8篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 79篇 |
妇产科学 | 10篇 |
基础医学 | 268篇 |
口腔科学 | 17篇 |
临床医学 | 138篇 |
内科学 | 419篇 |
皮肤病学 | 36篇 |
神经病学 | 191篇 |
特种医学 | 44篇 |
外科学 | 368篇 |
综合类 | 9篇 |
一般理论 | 31篇 |
预防医学 | 199篇 |
眼科学 | 11篇 |
药学 | 56篇 |
中国医学 | 1篇 |
肿瘤学 | 164篇 |
出版年
2022年 | 14篇 |
2021年 | 22篇 |
2020年 | 18篇 |
2019年 | 25篇 |
2018年 | 31篇 |
2017年 | 37篇 |
2016年 | 34篇 |
2015年 | 41篇 |
2014年 | 48篇 |
2013年 | 62篇 |
2012年 | 96篇 |
2011年 | 108篇 |
2010年 | 75篇 |
2009年 | 69篇 |
2008年 | 136篇 |
2007年 | 115篇 |
2006年 | 119篇 |
2005年 | 115篇 |
2004年 | 98篇 |
2003年 | 108篇 |
2002年 | 103篇 |
2001年 | 25篇 |
2000年 | 17篇 |
1999年 | 19篇 |
1998年 | 29篇 |
1997年 | 34篇 |
1996年 | 28篇 |
1995年 | 31篇 |
1994年 | 21篇 |
1993年 | 15篇 |
1992年 | 15篇 |
1991年 | 33篇 |
1990年 | 13篇 |
1989年 | 16篇 |
1988年 | 15篇 |
1986年 | 9篇 |
1985年 | 10篇 |
1984年 | 10篇 |
1983年 | 17篇 |
1982年 | 19篇 |
1981年 | 18篇 |
1979年 | 18篇 |
1977年 | 11篇 |
1976年 | 11篇 |
1975年 | 15篇 |
1974年 | 12篇 |
1973年 | 14篇 |
1971年 | 14篇 |
1968年 | 8篇 |
1967年 | 10篇 |
排序方式: 共有2047条查询结果,搜索用时 8 毫秒
101.
Sundquist M Thorstenson S Brudin L Stål O Nordenskjöld B 《Breast cancer research and treatment》2000,63(1):11-15
Flow cytometric DNA analysis with assessment of S-phase fraction and DNA ploidy was compared to Nottingham histologic grade. The study population consisted of 654 patients who presented between 1987 and 1996 with primary operable breast cancer and whose tumours had been analysed for S-phase fraction and DNA ploidy at the time of surgery. Grade, tumour size, node status, steroid receptor status, age, S-phase fraction and DNA ploidy were analysed univariately and multi-variately in a Cox proportional hazard analysis. In the univariate analyses all parameters were statistically significantly associated with breast cancer mortality during the follow-up period of 2–11 years. The most powerful predictor of death from breast cancer in the multiple regression analysis was grade. Patients with grade 1 tumours have excellent prognosis. We conclude that tumour grade is a strong prognostic indicator applicable to all breast cancer patients, regardless of size and nodal status, and advocate its general use. 相似文献
102.
103.
104.
The organization of the catecholamine innervation in the frontal lobe of the rat neocortex has been studied by means of the glyoxylic acid fluorescence method in combination with lesions and retrograde tracing of horseradish peroxidase. On the basis of fibre morphology and distribution of fibres and cell bodies of origin three dopaminergic terminal systems can be distinguished. The anteromedial system is formed by smooth axons originating in the medial part of the A10 cell group in the mesencephalon. The axons are distributed mainly in the pregenual part of the anteromedial cortex and the highest fibre density is found in the basal cortical layers. A much more sparse, caudal extension of this system is present in the supragenual part of the anteromedial cortex. The suprarhinal system forms the dorsal part of the dopaminergic innervation of the perirhinal cortex, surrounding the rhinal sulcus. It can be regarded as a direct lateral continuation of the anteromedial system, and can be followed from a coronal level just rostral to the nucleus accumbens to the level of the most rostral part of the caudate-puttamen. The axons are distributed mainly in the basal cortical layers and have their cell bodies of origin in the dorsolateral part of the A10 cell group. The supragenual system is formed by very fine, varicose axons distributed in a restricted area of the supragenual anteromedial cortex. The axons are localized in the superficial cortical layers (I–III) and the cell bodies of origin are distributed in the ventrolateral A10 and along the mediolateral extent of the substantia nigra (A9). Only one noradrenergic fibre system, originating in the locus coeruleus, was found. The locus coeruleus system projects to all parts of the frontal cortex. The medial cortex has the highest fibre density, the perirhinal somewhat lower, and the dorsal and lateral cortices are more sparsely innervated. In all cortical areas, the locus coeruleus innervation has the same general appearance with the highest fibre density in the molecular layer. 相似文献
105.
S Carlsson A Ljungqvist G Tornling G Unge 《Acta pathologica et microbiologica Scandinavica. Section A, Pathology》1978,86(4):297-301
Myocardial stereo-microangiography was performed on 30 rats after swimming exercise for one or two periods with and without a previous operation for production of aortic stenosis. In 8 rats with aortic stenosis no swimming exercise followed, and 10 more rats served as normal controls. Swimming exercise resulted in a higher degree of cardiac hypertrophy than aortic stenosis. Both types of cardiac hypertrophy resulted in vascular adaptive reactions in the myocardium. The adaptive reaction to swimming exercise was found to be persistent, at least to some extent, and to be of use if the exercise was resumed. The adaptive alterations in aortic stenosis were further modified by a superimposed period of exercise, although the nutritive capillary vasculature only showed a slight and focal increase in density. 相似文献
106.
107.
PURPOSE: To assess the psychosocial consequences of traffic accidents, and to evaluate the effect of an intervention programme to reduce the occurrence and extent of psychosocial residual states. MATERIAL AND METHODS: A telephone interview was conducted with 314 individuals, 1(1/2)-2 years after the accident in 1994-1995. The effect of the intervention programme was studied for inpatients, 68 in the study group, and 89 in the control group. The structured follow-up form included the Impact of Event Scale (IES). RESULTS: Half of those injured had residual physical complaints with negative effects on their work- and economic-situation. An influence on housing or the need for practical assistance was reported by 1-7%. Mental effects were reported by 4/5. IES demonstrated that 1/5 suffered a high degree of intrusion, and this occurred twice as often among females as among males. Situational anxiety occurred more often in the intervention group than in the control group, p=0.02. More individuals in the intervention group than in the control group were satisfied with the medical certificate to the insurance company, p=0.058. CONCLUSIONS: Females were afflicted by mental effects considerably more than males. The intervention programme did not appear to reduce the psychosocial sequelae. The methods within this area need to be further developed. 相似文献
108.
PURPOSE: The objective of this study was to determine whether mast cells (MC) in skin and thyroid gland, cutaneous nerve fibers and eosinophils are sensitive to the influence of electromagnetic fields (EMF). MATERIALS AND METHODS: The experiment was performed on two-month-old Wistar male rats, exposed to 50 Hz EMF (100-300 microT, 54-160 V/m) for 4 h a day, seven days a week during one month. After sacrifice, samples of skin and thyroid were processed for toluidine blue staining or indirect immunohistochemistry. The M42 grid placed in the ocular of a light microscope and a special microscopic frame placed in the ocular of a fluorescence microscope were used for stereological analysis. RESULTS: The numerical and volume density of intact type A MC in the thyroid of the exposed group was significantly higher compared to the control. A number of MC and immunoreactive nerve fibers were observed in the skin and of histamine-immunoreactive MC in the thyroid of exposed animals. The differences in stereological data were not statistically significant by the Mann-Whitney test. CONCLUSIONS: The results indicate certain alterations of cutaneous and thyroid MC in rats exposed to EMF. However, the possible outcome of changes in the MC population under EMF influence on morphophysiological properties of other structures in skin and thyroid requires further investigation. 相似文献
109.
110.
Januszkiewicz A Klaude M Loré K Andersson J Ringdén O Rooyackers O Wernerman J 《Clinical science (London, England : 1979)》2005,108(2):179-184
The palatine tonsils are constantly exposed to ingested or inhaled antigens which, in turn, lead to a permanent activation of tonsillar immune cells, even in a basic physiological state. The aim of the present study was to investigate if the immunological activation of the human palatine tonsil is reflected by a high metabolic activity, as determined by in vivo measurement of protein synthesis. The protein synthesis rate of the tonsil was also compared with that of the circulating T-lymphocytes, the total blood mononuclear cells and the whole population of blood leucocytes. Phenotypic characterization of immune-competent cells in tonsil tissue and blood was performed by flow cytometry. Pinch tonsil biopsies were taken after induction of anaesthesia in healthy adult patients (n=12) scheduled for ear surgery, uvulopalatopharyngoplasty or nose surgery. Protein synthesis was quantitatively determined during a 90-min period by a flooding-dose technique. The in vivo protein synthesis rate in the palatine tonsils was 22.8+/-5.7%/24 h (mean+/-S.D.), whereas protein synthesis in the circulating T-lymphocytes was 10.7+/-3.4%/24 h, in mononuclear cells was 10.8+/-2.8%/24 h and in leucocytes was 3.2+/-1.2%/24 h. CD3+ lymphocytes were the most abundant cell population in the tonsil. The in vivo protein synthesis rate in human tonsils was higher compared with the circulating immune cells. This high metabolic rate may reflect the permanent immunological activity present in human tonsils, although cell phenotypes and activity markers do not explain the differences. 相似文献