全文获取类型
收费全文 | 1074328篇 |
免费 | 93681篇 |
国内免费 | 4746篇 |
专业分类
耳鼻咽喉 | 17682篇 |
儿科学 | 34868篇 |
妇产科学 | 29319篇 |
基础医学 | 132916篇 |
口腔科学 | 27246篇 |
临床医学 | 102836篇 |
内科学 | 234564篇 |
皮肤病学 | 26698篇 |
神经病学 | 87137篇 |
特种医学 | 43615篇 |
外国民族医学 | 340篇 |
外科学 | 186444篇 |
综合类 | 20069篇 |
现状与发展 | 76篇 |
一般理论 | 273篇 |
预防医学 | 73450篇 |
眼科学 | 24489篇 |
药学 | 67248篇 |
1篇 | |
中国医学 | 2066篇 |
肿瘤学 | 61418篇 |
出版年
2021年 | 10225篇 |
2020年 | 10163篇 |
2019年 | 9536篇 |
2018年 | 17406篇 |
2017年 | 15074篇 |
2016年 | 16747篇 |
2015年 | 17837篇 |
2014年 | 28463篇 |
2013年 | 35726篇 |
2012年 | 33539篇 |
2011年 | 35093篇 |
2010年 | 27846篇 |
2009年 | 30460篇 |
2008年 | 33594篇 |
2007年 | 33640篇 |
2006年 | 35871篇 |
2005年 | 32591篇 |
2004年 | 30600篇 |
2003年 | 28527篇 |
2002年 | 28048篇 |
2001年 | 45217篇 |
2000年 | 45643篇 |
1999年 | 39499篇 |
1998年 | 13563篇 |
1997年 | 12462篇 |
1996年 | 12279篇 |
1995年 | 11495篇 |
1994年 | 9951篇 |
1993年 | 9082篇 |
1992年 | 29581篇 |
1991年 | 28408篇 |
1990年 | 27484篇 |
1989年 | 26538篇 |
1988年 | 24571篇 |
1987年 | 24044篇 |
1986年 | 23145篇 |
1985年 | 21908篇 |
1984年 | 16371篇 |
1983年 | 14004篇 |
1982年 | 8616篇 |
1979年 | 14918篇 |
1978年 | 10539篇 |
1977年 | 9025篇 |
1976年 | 8397篇 |
1975年 | 9259篇 |
1974年 | 10950篇 |
1973年 | 10437篇 |
1972年 | 9965篇 |
1971年 | 9134篇 |
1970年 | 8833篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
92.
93.
Case report 506 总被引:1,自引:0,他引:1
F. Bertoni M.D. V. Zucchi M.D. S. Mapelli M.D. P. Bacchini M.D. 《Skeletal radiology》1988,17(7):522-526
94.
Electrocardiographic symptoms were evaluated in 53 patients with an additional left-ventricular chorda (ALVC), detected by two-dimensional echocardiography. Signs of early ventricular repolarization (EVR) were identified in 45 (84.9%) patients. A transverse ALVC was more common in EVR-free patients (87.5%), as compared to patients with ALVC + EVR combinations (51.1%; p less than 0.05). 相似文献
95.
Peter Stone MD FRNZCOG FRCOG David Cook FRNZCOG MRCOG John Hutton PhD FRNZCOG FRCOG Gordon Purdie BSc Henry Murray MD FRNZCOG MRCOG Lauren Harcourt MPP BA 《The Australian & New Zealand journal of obstetrics & gynaecology》1995,35(1):32-37
Summary: This is the first report of the largest study of blood pressure measurement in pregnancy in a New Zealand population using standardized definitions and methodology. Over 3,800 women who delivered in an 8-month period in the Wellington region were included in the study. Blood pressure measurement and the presence of oedema and proteinuria were recorded from booking until delivery and in the puerperium. Only 2.7% of women were unable to be contacted after delivery for details on outcomes. The results established normal ranges for blood pressure throughout pregnancy. The data show that Mood pressure greater than 140/90 until 35 weeks' gestation is outside 2 standard deviations at all gestations and justifies using these measurements as the definition of hypertension in pregnancy. The fall in blood pressure in the 2nd trimester was less than 1 mm Ffg per week in both the systolic and diastolic pressures. This fall was smaller than previously recorded in other studies. Gestational hypertension was the commonest blood pressure abnormality occurring in 15.2% of the population. This represented 69% of the pregnant women with a hypertensive disorder. The overall incidence of both gestational hypertension and preeclampsia was 18.5% which is higher than reported in other parts of the world. In this study obesity was significantly associated with hypertensive disorders in pregnancy. An arm circumference of >33 cm, one of the measurements of obesity, was found in 6.8% of the study population. Even after the effect of arm circumference was taken into account, hypertensive disorders were also more common in Pacific Island women. Ankle oedema was significantly associated with the development of both gestational hypertension and preeclampsia but the incidence of oedema was noted in only 11.9% of the subjects. 相似文献
96.
97.
Localized proton magnetic resonance spectroscopy of a cerebellar tumor in a two-year-old child 总被引:1,自引:0,他引:1
B. Wilken G. Helms H. J. Christen J. Bhnk J. Frahm F. Hanefeld 《Child's nervous system》1996,12(10):626-629
Noninvasive localized proton magnetic resonance spectroscopy (MRS) was used for differential diagnosis of a focal brain lesion in a 2.5-year-old girl. The clinical signs were a mild head tilt and neck pain. Magnetic resonance imaging (MRI) revealed a lesion in the right hemisphere of the cerebellum, but its nature remained obscure. In this lesion quantitative determinations of cerebral metabolites by fully relaxed, short-echo-time proton MRS revealed markedly lowered N-acetylaspartate (NAA) and pronounced elevations of choline-containing compounds (Cho) and myo-inositol (Ins), whereas metabolite concentrations in cortical gray matter and white matter were within normal ranges. The metabolite pattern of the lesion indicated loss of vital neuroaxonal tissue (low NAA) and enhanced glial proliferation (high Cho and Ins), which, together with the MRI morphology, suggested a brain tumor. The diagnosis was established by neurosurgical exploration and total extirpation of the tumor. Histology confirmed an astrocytoma (WHO II). After 2 weeks' recovery the child was discharged with no neurological signs. 相似文献
98.
99.
100.
R. OREN Y. MAARAVI F. KARMELI G. KENET L. ZEIDEL A. HUBERT & R. ELIAKIM 《Alimentary pharmacology & therapeutics》1997,11(2):341-345
Background : Methimazole, an anti-thyroid drug, was recently found to be useful in the treatment of systemic lupus erythematosus and other autoimmune diseases. Moreover, decreased thyroid hormone production is associated with a variety of immunological manifestations, such as reduced activation of CD4+ cells, increased CD8+ cell activity and reduced soluble IL-2 receptors. In the present study we examined the effects of methimazole and propylthiouracil on a rat model of experimental colitis.
Methods : Colitis was induced by intracolonic administration of 30 mg trinitrobenzene sulphonic acid (TNB). Two weeks prior to induction of colitis, rats were treated by either methimaziole (0.04%) or propylthiouracil (0.01%) in drinking water after a week of free access to water. Rats were sacrificed 48 h or 7 days after induction of colitis. The colon was isolated, rinsed with ice-cold water and weighed. Damage was assessed both macroscopically and microscopically and myeloperoxidase (MPO) activity determined.
Results : All treated rats were hypothyroid as manifested by a significant elevation of thyroid stimulating hormone (TSH), by comparison with the control groups (mean -1.82±0.40 versus 0.11±0.02 mmol/L, respectively). The inflammatory response elicited by TNB resulted in severe mucosal damage 48 h after damage induction, which persisted for 7 days. Pre-treatment with either methimazole 0.04% or propylthiouracil 0.01% significantly decreased mucosal damage macroscopically (lesion area, lesion score and segmental weight) microscopically and also significantly decreased MPO level at both time points ( P <0.01).
Conclusions : Methimazole and propylthiouracil significantly reduce mucosal damage and colonic weight in a rat model of colitis. The mode by which they do so remains to be studied. 相似文献
Methods : Colitis was induced by intracolonic administration of 30 mg trinitrobenzene sulphonic acid (TNB). Two weeks prior to induction of colitis, rats were treated by either methimaziole (0.04%) or propylthiouracil (0.01%) in drinking water after a week of free access to water. Rats were sacrificed 48 h or 7 days after induction of colitis. The colon was isolated, rinsed with ice-cold water and weighed. Damage was assessed both macroscopically and microscopically and myeloperoxidase (MPO) activity determined.
Results : All treated rats were hypothyroid as manifested by a significant elevation of thyroid stimulating hormone (TSH), by comparison with the control groups (mean -1.82±0.40 versus 0.11±0.02 mmol/L, respectively). The inflammatory response elicited by TNB resulted in severe mucosal damage 48 h after damage induction, which persisted for 7 days. Pre-treatment with either methimazole 0.04% or propylthiouracil 0.01% significantly decreased mucosal damage macroscopically (lesion area, lesion score and segmental weight) microscopically and also significantly decreased MPO level at both time points ( P <0.01).
Conclusions : Methimazole and propylthiouracil significantly reduce mucosal damage and colonic weight in a rat model of colitis. The mode by which they do so remains to be studied. 相似文献