全文获取类型
收费全文 | 16431篇 |
免费 | 1118篇 |
国内免费 | 72篇 |
专业分类
耳鼻咽喉 | 76篇 |
儿科学 | 351篇 |
妇产科学 | 530篇 |
基础医学 | 2795篇 |
口腔科学 | 189篇 |
临床医学 | 1612篇 |
内科学 | 3908篇 |
皮肤病学 | 138篇 |
神经病学 | 1456篇 |
特种医学 | 549篇 |
外国民族医学 | 1篇 |
外科学 | 2583篇 |
综合类 | 143篇 |
一般理论 | 7篇 |
预防医学 | 958篇 |
眼科学 | 135篇 |
药学 | 1006篇 |
中国医学 | 21篇 |
肿瘤学 | 1163篇 |
出版年
2023年 | 50篇 |
2022年 | 92篇 |
2021年 | 221篇 |
2020年 | 132篇 |
2019年 | 255篇 |
2018年 | 329篇 |
2017年 | 207篇 |
2016年 | 267篇 |
2015年 | 358篇 |
2014年 | 472篇 |
2013年 | 686篇 |
2012年 | 1006篇 |
2011年 | 1127篇 |
2010年 | 712篇 |
2009年 | 692篇 |
2008年 | 1127篇 |
2007年 | 1135篇 |
2006年 | 1126篇 |
2005年 | 1187篇 |
2004年 | 1086篇 |
2003年 | 1064篇 |
2002年 | 1064篇 |
2001年 | 179篇 |
2000年 | 159篇 |
1999年 | 192篇 |
1998年 | 258篇 |
1997年 | 237篇 |
1996年 | 189篇 |
1995年 | 193篇 |
1994年 | 167篇 |
1993年 | 165篇 |
1992年 | 143篇 |
1991年 | 105篇 |
1990年 | 89篇 |
1989年 | 84篇 |
1988年 | 80篇 |
1987年 | 64篇 |
1986年 | 71篇 |
1985年 | 51篇 |
1984年 | 70篇 |
1983年 | 56篇 |
1982年 | 71篇 |
1981年 | 87篇 |
1980年 | 44篇 |
1979年 | 42篇 |
1978年 | 41篇 |
1977年 | 28篇 |
1976年 | 28篇 |
1975年 | 31篇 |
1973年 | 21篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
61.
Czeslaw J. Lewa Jacques D. de Certaines 《Journal of magnetic resonance imaging : JMRI》1995,5(2):242-244
Mechanical waves in magnetic resonance imaging, which have been suggested for possible clinical applications, were analyzed with regard to imaging of the viscoelastic properties of large objects. The method is based on the Larmor frequency modulation caused by the application of mechanical waves. Possible clinical applications include all diseases that result in a change in the mechanical properties of biologic tissues (eg, atherosclerosis). 相似文献
62.
B n dicte Brichard Jacques Ninane Serge Gosseye Christine Verellen-Dumoulin Christiane Vermylen Jean Rodhain Guy Comu 《Pediatric hematology and oncology》1991,8(3):215-219
A 9-year-old boy presented with a small subcutaneous tumor of the trunk and diffuse bone marrow involvement. The first histological diagnosis given was undifferentiated malignancy possibly of neural crest origin and chemotherapy was started immediately using vincristine, cyclophosphamide, cisplatin, and teniposide (OPEC). Complete response was achieved after four courses of chemotherapy. Histological slides were then reviewed and the final diagnosis of alveolar rhabdomyosarcoma (RMS) was retained. Moreover, chromosome analysis of malignant cells in the bone marrow revealed a translocation involving chromosomes 2 and 13:t(2;13) (q35;q14). This specific karyotype finding has been recently reported in a few cases and could be specific for alveolar RMS. The patient had a relapse 7 months after diagnosis and died 4 months later. 相似文献
63.
Patrice Venault Georges Chapouthier Jacques Simiand Robert H. Dodd Jean Rossier 《Brain research bulletin》1987,19(3)
Benzodiazepines are known to induce a profound anterograde amnesia in man. In this report, it is shown that methyl β-carboline-3-carboxylate (β-CCM), an inverse agonist of the benzodiazepine receptor, has the opposite effect; it enhances performance in learning and memory tasks. Three different learning models were used: habituation to a new environment and passive avoidance in mice and imprinting in chicks. The opposite effects of both β-CCM and the benzodiazepine diazepam were blocked by administration of the benzodiazepine receptor antagonist Ro 15-1788, provicling evidence that the benzodiazepine receptor is involved in these effects. 相似文献
64.
P F Jacques S C Hartz R B McGandy R A Jacob R M Russell 《Journal of the American College of Nutrition》1987,6(2):169-174
The relationships between ascorbic acid (plasma and dietary) and plasma HDL cholesterol (HDL-C), total plasma cholesterol (T-C) and T-C:HDL-C ratio were examined in a population of 235 males and 445 females, age 60-98 years. Many known or suspected determinants of HDL-C and T-C, including age, sex, triceps skinfold thickness, fasting blood glucose, alcohol intake, and others, were considered as covariates due to their potential confounding or modifying effects on the relationships under study. The results show that plasma ascorbic acid is significantly (p less than 0.05) correlated with HDL-C (r = 0.09), T-C:HDL-C (r = 0.10), but not with T-C (r = 0.03). There is a strong age interaction with the largest effect of ascorbic acid in the youngest age group studied (60-69 years). The effects of dietary ascorbic acid are similar but slightly reduced in magnitude. 相似文献
65.
66.
Patrick Fransen MD Jacques Favre MD Philippe Maeder MD Heinz Fankhauser MD 《Journal of clinical neuroscience》1994,1(4):274-276
Lhermitte-Duclos disease (dysplastic gangliocytoma of the cerebellum) is a rare pseudo-neoplastic disorder of the cerebellum with typical MRI findings. A 25-year-old man presenting with progressive neck pain, dizziness, and impaired vision is reported. CT and MRI revealed a left cerebellar haemispheric mass and obstructive hydrocephalus. Lhermitte-Duclos disease was histologically confirmed after surgical removal of the lesion. The typical MRI appearance of a nonenhancing haemispheric cerebellar mass with preservation and exaggeration of the normal gyral pattern allows pre-operative diagnosis of this condition. The literature is reviewed and clinical presentation, radiology and histopathology are discussed. 相似文献
67.
A spontaneous lymphoid thymus tumor was discovered in a male Xenopus of the MHC
ff genotype. The tumor cell can be transplanted in histocompatible larval ff hosts, but not
in ff adults unless irradiated (3000 rad). The tumor is rejected by allogeneic hosts. The
tumor cells express neither markers of the B-cell lineage nor MHC encoded molecules;
they express only markers of the T-cell lineage. Its lymphoid population is clonal as
revealed by the existence of a stable rearrangement pattern of the immunoglobulin
genes. Cell lines growing continuously in vitro have been derived from the tumor. 相似文献
68.
Elisabeth Rodier Hubert Lochard Martial Sauceau Jean-Jacques Letourneau Bernard Freiss Jacques Fages 《European journal of pharmaceutical sciences》2005,26(2):184-193
The aim of this study is to improve the dissolution properties of a poorly-soluble active substance, Eflucimibe by associating it with gamma-cyclodextrin. To achieve this objective, a new three-step process based on supercritical fluid technology has been proposed. First, Eflucimibe and cyclodextrin are co-crystallized using an anti-solvent process, dimethylsulfoxide being the solvent and supercritical carbon dioxide being the anti-solvent. Second, the co-crystallized powder is held in a static mode under supercritical conditions for several hours. This is the maturing step. Third, in a final stripping step, supercritical CO(2) is flowed through the matured powder to extract the residual solvent. The coupling of the first two steps brings about a significant synergistic effect to improve the dissolution rate of the drug. The nature of the entity obtained at the end of each step is discussed and some suggestions are made as to what happens in these operations. It is shown the co-crystallization ensures a good dispersion of both compounds and is rather insensitive to the operating parameters tested. The maturing step allows some dissolution-recrystallization to occur thus intensifying the intimate contact between the two compounds. Addition of water is necessary to make maturing effective as this is governed by the transfer properties of the medium. The stripping step allows extraction of the residual solvent but also removes some of the Eflucimibe which is the main drawback of this final stage. 相似文献
69.
Gustave Savourey Nathalie Garcia Jean Pierre Caravel Claude Gharib Nadine Pouzeratte Serge Martin Jacques Bittel 《European journal of applied physiology》1997,77(1-2):37-43
High altitude residence is known to modify body biochemistry and hormone status. However, the effects of such a sojourn on these status observed at sea level both immediately and later after return are not as well established as are the effects of an intermittent acclimation. The aim of this study was therefore to investigate these changes. To achieve our objectives, nine subjects received intermittent acclimation at low pressure in a barometric chamber (8?h daily for 5 days, day 1 at 4500 m, day 5 at 8500 m) before an expedition to the Himalayas. Hormonal and biochemical changes were studied using samples of venous blood taken at sea level before and after acclimation, after return from the expedition and 1 and 2 months after descent. Concentrations of thyroid hormones, adrenaline, noradrenaline (NA), hormones of hydromineral metabolism (aldosterone, renin, arginine vasopressin, atrial natriuretic peptide) as well as prolactin, cortisol, insulin and endothelin 1 were measured. Biochemical measurements made were plasma osmolality, and concentrations of glucose, total cholesterol, total proteins, pre-albumin, transferrin, complement 3C, apolipoproteins A1 and B and serum iron. Acclimation induced no alteration in hormone (except for NA with increases of about 1.5, fold P<0.05) and biochemistry data. After the expedition, hormone responses were characterized by a higher total triidothyronine concentration (+18%, P<0.05) while other hormones did not vary. A linear relationship was found between thyroid-stimulating-hormone and body mass changes after the expedition (r=0.67, P<0.05). The observed increased concentrations of plasma proteins and total cholesterol (P<0.05) could be related to the restoration of lean body mass. At 1 and 2 months after return, no changes in hormones were observed but a significant decrease in transferrin concentration was noticed. The higher serum iron concentration reported after 1 month (P<0.05) could have been the result of a physiological haemolysis. It was concluded that both acclimation and the expedition in the Himalayas affected hormone status and body biochemistry status even though the observed changes were slight and rapidly reversed. 相似文献
70.