全文获取类型
收费全文 | 78800篇 |
免费 | 4881篇 |
国内免费 | 1173篇 |
专业分类
耳鼻咽喉 | 790篇 |
儿科学 | 1842篇 |
妇产科学 | 1691篇 |
基础医学 | 9144篇 |
口腔科学 | 2329篇 |
临床医学 | 6631篇 |
内科学 | 19616篇 |
皮肤病学 | 1126篇 |
神经病学 | 7567篇 |
特种医学 | 2998篇 |
外国民族医学 | 2篇 |
外科学 | 11248篇 |
综合类 | 2180篇 |
现状与发展 | 1篇 |
一般理论 | 7篇 |
预防医学 | 3768篇 |
眼科学 | 1119篇 |
药学 | 5656篇 |
8篇 | |
中国医学 | 1059篇 |
肿瘤学 | 6072篇 |
出版年
2023年 | 751篇 |
2022年 | 1676篇 |
2021年 | 2770篇 |
2020年 | 1735篇 |
2019年 | 2093篇 |
2018年 | 2401篇 |
2017年 | 1943篇 |
2016年 | 2088篇 |
2015年 | 2444篇 |
2014年 | 3208篇 |
2013年 | 3895篇 |
2012年 | 5559篇 |
2011年 | 5497篇 |
2010年 | 3198篇 |
2009年 | 2937篇 |
2008年 | 4539篇 |
2007年 | 4675篇 |
2006年 | 4301篇 |
2005年 | 3987篇 |
2004年 | 3587篇 |
2003年 | 3178篇 |
2002年 | 2828篇 |
2001年 | 1722篇 |
2000年 | 1657篇 |
1999年 | 1547篇 |
1998年 | 693篇 |
1997年 | 533篇 |
1996年 | 509篇 |
1995年 | 419篇 |
1994年 | 387篇 |
1993年 | 327篇 |
1992年 | 819篇 |
1991年 | 687篇 |
1990年 | 652篇 |
1989年 | 622篇 |
1988年 | 570篇 |
1987年 | 504篇 |
1986年 | 465篇 |
1985年 | 410篇 |
1984年 | 335篇 |
1983年 | 266篇 |
1982年 | 165篇 |
1981年 | 129篇 |
1979年 | 262篇 |
1978年 | 161篇 |
1977年 | 135篇 |
1974年 | 148篇 |
1973年 | 153篇 |
1972年 | 145篇 |
1971年 | 126篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
S C Hill B M Damaska A Ling K Patterson A M Di Bisceglie R O Brady N W Barton 《Radiology》1992,184(2):561-566
Abdominal magnetic resonance imaging findings were reviewed in 46 patients with Gaucher disease. All patients had hepatosplenomegaly at the time of initial imaging. Splenic nodules were present in 14 patients (30%) and varied in signal intensity. These nodules were isointense on T1-weighted and hypointense on T2-weighted images. Splenic infarcts were seen in 15 patients (33%), and four of these patients (9%) also had subcapsular fluid collections. Both nodules and infarcts were present in the spleen in four patients (9%). Pathologic correlation was performed with specimens from two patients who underwent partial splenectomy. Focal areas of abnormal signal intensity were noted in the liver in nine patients (20%). They were either stellate or segmental, and may represent fibrotic septa with ischemic changes associated with aggregates of Gaucher cells. No changes were noted in the kidneys or abdominal lymph nodes. 相似文献
82.
M Panella G Mignemi C Gretter L Di Leo V F Guardalà G Garozzo 《Clinical and experimental obstetrics & gynecology》1992,19(1):25-29
We report a retrospective analysis of 1202 deliveries assisted by the same medical team, evaluating the clinical management of labour and the resulting type of delivery. Examination of the data revealed a gradual reduction in the number of deliveries treated pharmacologically accompanied by a reduction in the incidence of operative deliveries from 16% to 6%. Statistical analysis of the data using X2 test demonstrated a clear correlation between the administration of oxytocin and the incidence of operative deliveries (p less than or equal to 0.001). We believe that the indiscriminate use of oxytocin in labour should be avoided and that the pharmacological and operative management of labour requires precise clinical indications. 相似文献
83.
84.
M Longobardi A Bargagna E Mariani P Schenone S Vitagliano L Stella A Di Sarno E Marmo 《Il Farmaco; edizione pratica》1990,45(4):399-404
The synthesis of some N,N-disubstituted 4-amino-5,6-dihydro-3-phenyl-2H-[1]benzothiepino [5,4-b]pyran-2-ones by reaction of phenylchloroketene with a series of N,N-disubstituted (E)-4-aminomethylene-3,4-dihydro-1-benzothiepin-5(2H)-ones, followed by dehydrochlorination of the primary adducts with DBN, is described. The 4-methylphenylamino derivative showed a local anesthetic activity in mice superior to that of lidocaine and the 4-morpholino derivative showed an antiarrhythmic activity in rats comparable to that of quinidine. 相似文献
85.
F lix F. Cruz-Sanchez Marco L. Rossi Adriana Cardozo Ana Picardo E. Tolosa 《Journal of the neurological sciences》1992,110(1-2):228-231
The grumose degeneration observed in the dentate nuclei of 7 cases of progressive supranuclear palsy (PSP) was studied with a panel of antibodies which included 2 neurofilaments, Tau and ubiquitin. Dentate nucleus neurons were negative with all antibodies except ubiquitin which showed a slightly positive homogeneous pattern of staining. The amorphous material surrounding swollen or normal neurons was strongly positive for neurofilament and subunits and numerous torpedoes were observed in the granular layer of the cerebellar cortex. Our results confirm that grumose degeneration consists in degeneration of terminal axons of Purkinje cells in the dentate nucleus. The positivity of dentate nucleus neurons for ubiquitin may support the concept of synaptic dysfunction between Purkinje cells and dentate nucleus neurons. 相似文献
86.
The octadecyl rhodamine (R18) fluorescent dequenching assay was used to examine membrane fusion between mumps virus and mammalian cells. Rapid fluorescent dequenching, indicative of membrane fusion, was observed when labeled mumps virus was mixed with either ghost erythrocytes or CV-1 cells. After 15 min a saturation limit of 18 virus per erythrocyte ghost and 6400 virus per CV-1 cell was observed. Fetuin was found to inhibit virus fusion, suggesting a role for sialic acid in virus binding to the cells. Two dequenching processes were observed of which the faster process is thought to be membrane fusion and the second process is thought to be probe proximal transfer. 相似文献
87.
88.
89.
P.M. Rossini G. Martino L. Narici A. Pasquarelli M. Peresson V. Pizzella F. Tecchio G. Torrioli G.L. Romani 《Brain research》1994,642(1-2)
Transient rearrangements of finger representation in primary somatosensory cortex induced by an anesthetic block of the sensory information from adjacent fingers have been shown invasively in animals. Such a phenomenon has been now replicated in seven healthy human volunteers. Somatosensory Evoked Fields (SEFs) have been recorded during separate electrical stimulation of the 1st, 3rd, or 5th finger. Recordings were obtained in control conditions (stage A), following complete ischemic anesthesia of the 4 non-stimulated fingers (stage B), and after regaining sensation (stage C). SEFs were recorded using a 28-channel DC-SQUID magnetometer; a single position of the sensor was enough to identify the source of N20m, P30m and following components using the Equivalent Current Dipole (ECD) model. The amount of afferent input during stages A through C was monitored with surface electrodes placed on the nerve at wrist and elbow. No variation of the nerve compound potential was observed during stages A through C. In stage A, the localizing algorithm was able to discriminate the individual finger representation in accordance with the somatotopic organisation of the sensory homunculus. It was observed that the ECDs responsible for the cortical responses from the unanesthetized finger were significantly changing following a relatively brief period of sensory deprivation from the adjacent fingers. Such changes of the ECDs with respect to the control conditions were characterized by an increase in strength and deepening for the middle finger, and by a shift on the coronal plane for the thumb and the little finger (medial for the former, lateral for the latter). Such changes became progressively evident in stage B, but were persisting in stage C. 相似文献
90.