全文获取类型
收费全文 | 876156篇 |
免费 | 71872篇 |
国内免费 | 2889篇 |
专业分类
耳鼻咽喉 | 12921篇 |
儿科学 | 24775篇 |
妇产科学 | 25254篇 |
基础医学 | 125812篇 |
口腔科学 | 25667篇 |
临床医学 | 77164篇 |
内科学 | 166517篇 |
皮肤病学 | 17069篇 |
神经病学 | 70803篇 |
特种医学 | 35640篇 |
外国民族医学 | 181篇 |
外科学 | 137614篇 |
综合类 | 27595篇 |
现状与发展 | 8篇 |
一般理论 | 264篇 |
预防医学 | 67733篇 |
眼科学 | 20839篇 |
药学 | 66234篇 |
15篇 | |
中国医学 | 2467篇 |
肿瘤学 | 46345篇 |
出版年
2018年 | 7780篇 |
2015年 | 8363篇 |
2014年 | 11907篇 |
2013年 | 17499篇 |
2012年 | 23792篇 |
2011年 | 25015篇 |
2010年 | 14690篇 |
2009年 | 13712篇 |
2008年 | 23346篇 |
2007年 | 25386篇 |
2006年 | 25269篇 |
2005年 | 24881篇 |
2004年 | 24171篇 |
2003年 | 23262篇 |
2002年 | 22312篇 |
2001年 | 36174篇 |
2000年 | 36767篇 |
1999年 | 31207篇 |
1998年 | 9408篇 |
1997年 | 8737篇 |
1996年 | 8633篇 |
1995年 | 8138篇 |
1994年 | 7826篇 |
1992年 | 26735篇 |
1991年 | 26167篇 |
1990年 | 25688篇 |
1989年 | 24733篇 |
1988年 | 23252篇 |
1987年 | 22918篇 |
1986年 | 21780篇 |
1985年 | 21114篇 |
1984年 | 16394篇 |
1983年 | 14003篇 |
1982年 | 8860篇 |
1981年 | 8203篇 |
1980年 | 7671篇 |
1979年 | 16740篇 |
1978年 | 12114篇 |
1977年 | 10181篇 |
1976年 | 9328篇 |
1975年 | 10147篇 |
1974年 | 12641篇 |
1973年 | 12136篇 |
1972年 | 11538篇 |
1971年 | 10685篇 |
1970年 | 10218篇 |
1969年 | 9909篇 |
1968年 | 8900篇 |
1967年 | 8230篇 |
1966年 | 7653篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
161.
D Lozińska I Radomska E Niedzicka E Dmoch W Czerwoniec 《Archivum immunologiae et therapiae experimentalis》1987,35(6):769-773
The results of treatment with intrauterine transfusion are presented. The analysis comprised 48 successful transfusions into 29 foetuses. The reference group consisted of 11 transfusions which proved nonfeasible or ineffective and 54 untreated cases. Following blood treatment, the newborn mortality rate dropped more than threefold. Long-term follow-up of 21 children generally showed their good physical and mental development. We also present 4 cases of supsequent pregnancies after intrauterine blood treatment in a preceding pregnancy, showing that it is possible to save the next baby of the same mother. 相似文献
162.
Following surgical correction of chronic aortic regurgitation, left ventricular (LV) volume falls to normal or near normal in most patients; this change generally occurs within the first week after surgery. During the ensuing six months, a significant regression of LV hypertrophy occurs, but most patients do not achieve a normal LV mass. The systolic ejection fraction may increase while the LV end-diastolic pressure almost uniformly falls to normal. Postoperative studies of LV volume mass and function should be aimed at identifying those patients which do not undergo these favorable changes so that medical therapy can be directed at this high risk group. 相似文献
163.
Symptoms of tobacco withdrawal. A replication and extension 总被引:19,自引:0,他引:19
Smokers (n = 315) who wished to quit were randomly assigned in a double-blind manner to groups using either nicotine or placebo gum. Self-reported and observed symptoms of tobacco withdrawal were collected before cessation and at follow-ups of 1 to 2 weeks, 1 month, and 6 months. Self-reported and/or observed anger, anxiety, craving, difficulty concentrating, hunger, impatience, and restlessness were the most prominent symptoms of tobacco withdrawal. These symptoms had returned to precessation levels by 1 month except increased weight, hunger, and craving continued for 6 months in many smokers. Nicotine gum decreased most symptoms, including craving and hunger but not weight. Abstinent smokers with more intense withdrawal were not more likely to relapse. Abstinent smokers who gained more weight were less likely to relapse. 相似文献
164.
alpha 2-Adrenergic receptors (ARs) are involved in central nervous system (CNS) control of blood pressure. It is now known that there are three human genes that encode subtypes of alpha 2-ARs, but little is known regarding the distribution of these subtypes throughout the CNS. The availability of receptor clones allows the mapping of mRNAs encoding the individual alpha 2-AR subtypes in the CNS. In this communication, we report that there are three, closely related rat alpha 2-AR genes. We have developed subtype-specific hybridization probes from each of these genes and have used these reagents to measure alpha 2-AR subtype mRNA accumulation in extracts of discrete regions of the rat CNS. We found that mRNAs encoding the alpha 2A-AR and alpha 2C-AR subtypes are distributed widely, but unevenly, throughout the rat CNS. The A subtype is prominent in the midbrain, brainstem, spinal cord, pituitary and diencephalon while the C subtype predominates in basal ganglia and cerebellum. The cortex, olfactory bulb and hippocampus contain roughly equal amounts of the alpha 2A- and alpha 2C-AR mRNAs. A third subtype's (alpha 2B-AR) mRNA is far less abundant in brain tissues, and is only found in the diencephalon. 相似文献
165.
Cloning and characterization of Ca(2+)-dependent and Ca(2+)-independent PKCs expressed in Aplysia sensory cells 总被引:2,自引:0,他引:2
K E Kruger W S Sossin T C Sacktor P J Bergold S Beushausen J H Schwartz 《The Journal of neuroscience》1991,11(8):2303-2313
We isolated cDNA clones from an Aplysia sensory-cell library encoding two isoforms of protein kinase C (PKC). Several isozyme-specific regions are conserved in the Aplysia kinases, notably the variable regions V5 in the Ca(2+)-dependent PKC (Apl I) and V1 in the Ca(2+)-independent PKC (Apl II). Neuronal proteins with the properties expected of these two isoforms can be identified with antibodies raised against peptides synthesized from the amino acid sequences deduced from the clones. Sacktor and Schwartz (1990) measured the proportion of kinase activity that can be translocated to membrane in Aplysia sensory neurons and ganglia by stimuli that produce the presynaptic facilitation underlying behavioral sensitization. Much less Apl I and Apl II are translocated, suggesting that still other isoforms of PKC exist in these cells. 相似文献
166.
J W Rose H Lorberboum-Galski D Fitzgerald R McCarron K E Hill J J Townsend I Pastan 《Journal of neuroimmunology》1991,32(3):209-217
IL2-PE40 is a chimeric protein composed of human interleukin-2 (IL2) genetically fused to a modified form of Pseudomonas exotoxin lacking the cell recognition domain. IL2-PE40 is cytotoxic for IL2 receptor-bearing lymphocytes in culture and can inhibit activation of T cells in vivo. IL2-PE40 can significantly diminish antigen-stimulated proliferation of lymphocytes sensitized to myelin basic protein. Intraperitoneal administration of IL2-PE40 not only markedly inhibits the clinical manifestations of adoptively transferred relapsing experimental allergic encephalomyelitis but also dramatically reduces both inflammation and demyelination characteristic of the disease. 相似文献
167.
The analysis of vestibular responses in a comatose patient often provides the critical information for making a correct preliminary diagnosis and directing the subsequent laboratory evaluation. Because of some uncertainties about what is being tested with the various bedside maneuvers that are used to elicit vestibular responses, we review the physiologic basis for the oculomotor responses that occur with head rotation or with caloric stimuli. We further urge precise and unambiguous terminology to describe both stimulus and response. We suggest using physiologically well-defined terms such as vestibulo-ocular reflex and cervico-ocular reflex and avoiding potentially misleading terms such as the doll's head and the oculocephalic maneuvers. 相似文献
168.
169.
A primary intrascrotal mass clinically mimicking a testicular tumor was found to be a desmoid tumor originating from the spermatic cord. To our knowledge, this is the first reported case of a paratesticular desmoid tumor. 相似文献
170.
Rats were killed after 6 weeks of continuous ingestion of the pneumotoxic alkaloid monocrotaline (2.2 mg/kg/day), the neutrophil elastase inhibitor SC39026 (60 mg/kg/day), or both. Pulmonary reactions were evaluated by light and electron microscopy. Lung endothelial function was monitored by angiotensin converting enzyme (ACE) activity, plasminogen activator (PLA) activity, and prostacyclin (PGI2) and thromboxane (TXA2) production. Lung hydroxyproline content was measured as an index of interstitial fibrosis. Cardiac right ventricular hypertrophy was determined by the right ventricle to the left ventricle plus septum weight ratio (RV/LV + S). Rats receiving SC39026 alone did not differ significantly from untreated control animals with respect to any of the quantitative endpoints, although rarefaction of Type I pneumocytes was observed in the electron micrographs of these animals. Monocrotaline-treated rats, in contrast, developed a significant increase in RV/LV + S, and exhibited pulmonary edema, inflammation, fibrosis, and muscularization and occlusive mural thickening of the pulmonary small arteries and arterioles. These monocrotaline-induced structural changes were accompanied by decreased lung ACE and PLA activities, and increased PGI2 and TXA2 production, and by an increase in lung hydroxyproline content. Cotreatment with SC39026 ameliorated the monocrotaline-induced pulmonary vascular wall thickening and the cardiac right ventricular hypertrophy. These data suggest that inappropriate neutrophil elastase activity contributes to monocrotaline pulmonary vasculopathy and hypertension. On the other hand, cotreatment with SC39026 had no significant effect on the severity of the monocrotaline-induced lung inflammatory reaction, the pulmonary endothelial dysfunction, or the increase in lung hydroxyproline content. 相似文献