全文获取类型
收费全文 | 344477篇 |
免费 | 22953篇 |
国内免费 | 7684篇 |
专业分类
耳鼻咽喉 | 4081篇 |
儿科学 | 9657篇 |
妇产科学 | 6571篇 |
基础医学 | 27647篇 |
口腔科学 | 8007篇 |
临床医学 | 38328篇 |
内科学 | 43353篇 |
皮肤病学 | 4599篇 |
神经病学 | 19732篇 |
特种医学 | 7863篇 |
外国民族医学 | 31篇 |
外科学 | 36561篇 |
综合类 | 50937篇 |
现状与发展 | 12篇 |
一般理论 | 29篇 |
预防医学 | 35398篇 |
眼科学 | 5353篇 |
药学 | 31751篇 |
396篇 | |
中国医学 | 31267篇 |
肿瘤学 | 13541篇 |
出版年
2024年 | 1136篇 |
2023年 | 5648篇 |
2022年 | 9909篇 |
2021年 | 13635篇 |
2020年 | 12735篇 |
2019年 | 18628篇 |
2018年 | 16135篇 |
2017年 | 13000篇 |
2016年 | 10491篇 |
2015年 | 9822篇 |
2014年 | 20087篇 |
2013年 | 21645篇 |
2012年 | 18367篇 |
2011年 | 19856篇 |
2010年 | 15926篇 |
2009年 | 14633篇 |
2008年 | 14210篇 |
2007年 | 14666篇 |
2006年 | 12784篇 |
2005年 | 11106篇 |
2004年 | 9026篇 |
2003年 | 7931篇 |
2002年 | 6245篇 |
2001年 | 5607篇 |
2000年 | 4637篇 |
1999年 | 3995篇 |
1998年 | 3257篇 |
1997年 | 3108篇 |
1996年 | 2694篇 |
1995年 | 2583篇 |
1994年 | 2493篇 |
1993年 | 1989篇 |
1992年 | 2017篇 |
1991年 | 1736篇 |
1990年 | 1546篇 |
1989年 | 1378篇 |
1988年 | 1304篇 |
1985年 | 3793篇 |
1984年 | 4800篇 |
1983年 | 3343篇 |
1982年 | 3802篇 |
1981年 | 3549篇 |
1980年 | 3158篇 |
1979年 | 2906篇 |
1978年 | 2534篇 |
1977年 | 1907篇 |
1976年 | 2151篇 |
1975年 | 1636篇 |
1974年 | 1433篇 |
1973年 | 1280篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
141.
本文从信息经济学的角度出发,分析了病案信息的经济价值、市场需求及其开发利用,揭示了病案信息利用对相关市场参与者的利润、效用、福利增进的机制及在疾病控制中的重大作用,指明了加强病案信息开发的重要性和紧迫性,并提出建议。 相似文献
142.
G Kellner T Popow-Kraupp C Binder I Goedl M Kundi C Kunz 《Journal of medical virology》1991,35(4):267-272
Rhinoviruses were isolated from nasopharyngeal secretions of 49 children hospitalized because of severe respiratory tract infection. The isolates were typed using 90 type-specific antisera. No obvious relation between certain serotypes and the severity of illness was found. Serum samples were drawn from all children simultaneously with the nasopharyngeal secretions and screened for the presence of type-specific neutralizing antibodies. Children aged 1 week to 6 months had higher neutralizing antibody titers and revealed a lower degree of morbidity than older children. The decline of neutralizing serum antibodies with increasing age was correlated with a higher incidence of severe disease in those aged 7-12 months. Nevertheless, also in this age group children with mild clinical courses of disease were observed despite a low concentration or an absence of neutralizing serum antibodies. This indicates that not only neutralizing serum antibodies, but other factors also influence the clinical expression of RHV-induced disease. 相似文献
143.
144.
The effect of the experimental antiepileptic drug zonisamide (1,2-benzisoxazole-3-methanesulfonamide, ZNS) on the trigeminal complex of cats was compared with the effect of established antiepileptic drugs. Intravenous administration of 10-40 mg/kg ZNS significantly depresses descending excitatory mechanisms, as well as segmental and descending inhibitory mechanisms, but has only a minor effect on segmental excitatory mechanisms. This spectrum of activity is similar to that of valproate, and suggests that ZNS should also be a broad-spectrum antiepileptic drug. In agreement with our experimental observations, it has been found that ZNS is effective against complex partial, generalized tonic clonic, and myoclonic seizures. The antiepileptic profile of ZNS in conventional screening tests resembles that of carbamazepine (CBZ) and phenytoin. However, CBZ exacerbates rather than prevents myoclonic seizures. Our experimental model thus provides a more accurate prediction of ZNS's clinical spectrum of activity. The relationship of these findings to the mechanism of action of antiepileptic drugs is discussed. 相似文献
145.
Summary Cerebellar nuclear afferents from some caudal brain stem nuclei in the cat were studied by means of retrograde transport after implantation of the wheat germ agglutinin-horseradish peroxidase complex in crystalline form in the cerebellar nuclei. The findings give evidence that projections to the cerebellar nuclei from certain nuclei of the reticular formation proper (e.g., from the gigantocellular reticular nucleus) are very modest, while there appears to be no or extremely few cerebellar nuclear afferents from the paramedian reticular, spinal trigeminal, gracile, cuneate and external cuneate nuclei. Previous tracer studies have given evidence that also the pontine and red nuclei send very few, if any, fibres to the cerebellar nuclei. All these brain stem regions are known to project to the cerebellar cortex. This relative lack of mossy fibre collaterals to the cerebellar nuclei is discussed with references to previous literature on the distribution of cerebellar nuclear afferents, and the problem of how the cerebellar nuclei are facilitated is considered.Abbreviations
Br.c.
superior cerebellar peduncle (brachium conjunctivum)
-
Br.p.
middle cerebellar peduncle (brachium pontis)
-
C.r.
interior cerebellar peduncle (restiform body)
-
HRP
horseradish peroxidase
-
L
left
-
N.c.
cuneate nucleus
-
N.c.e.
external cuneate nucleus
-
N.c.t.
nucleus of corpus trapezoideum
-
NIA
anterior interposed nucleus
-
NIP
posterior interposed nucleus
-
NL
lateral (dentate) nucleus
-
N.l.l.
nuclei of lateral lemniscus
-
NM
medial (fastigial) nucleus
-
N.m.X.
dorsal motor vagal nucleus
-
N.mes.
mesencephalic trigeminal nucleus
-
N.r.l.
lateral reticular nucleus (nucleus of the lateral funiculus)
-
N.r.p.
paramedian reticular nucleus
-
N.r.t.
reticular tegmental pontine nucleus
-
N V, VI, VII, XII
root fibres of cranial nerves
-
Ol.s.
superior olive
-
P.h.
nucleus praepositus hypoglossi
-
Py
pyramid
-
R
right
-
R.gc.
gigantocellular reticular nucleus
-
R.l.
lateral reticular nucleus of Meessen and Olszewski
-
R.p.c.
caudal pontine reticular nucleus
-
R.pc.
parvicellular reticular nucleus
-
R.v.
ventral reticular nucleus
-
Tr.sp.V.
spinal tract of the trigeminal nerve
-
T.s.
solitary tract surrounded by nucleus of solitary tract
-
V.m.
medial vestibular nucleus
-
WGA
wheat germ agglutinin
-
WGA-HRP
wheat germ agglutinin-horseradish peroxidase conjugate
-
V, VI, VII, X, XII
motor nuclei of cranial nerves 相似文献
146.
[目的]探讨不同起搏模式对病人生存质量(QOL)的影响。[方法]以健康调查问卷(SF一36量表)对112例不同起搏模式病人进行问卷调查,比较3种起搏模式下病人的QOL水平。[结果]除机体疼痛、角色情绪2个维度外其余6个维度(生理功能、角色限制、活力、社会功能、精神健康、总体健康)3种起搏模式间比较差异有统计学意义(P〈0.05)。[结论]应用AAI型、DDD型起搏器的病人生存质量优于VVI型起搏。 相似文献
147.
J. Pillgram-Larsen J. Thorvaldson E. Thaulow G. Semb A. Serck-Hanssen 《European journal of cardio-thoracic surgery》1987,1(3):183-185
A rare case of a rhabdomyoma originating from the surface of the right atrium in a 20-year-old female is reported. The tumor showed electrical activity and caused both outflow obstruction and tamponade symptoms. It was successfully removed by a right-sided thoracotomy. The clinical course, diagnostic investigations, and the therapeutical approach of this rare lesion are discussed. 相似文献
148.
A direct solution is proposed to an optimal control problem of linear econometric systems with a quadratic welfare loss function when there are linear equality constraints on the control variables. The direct solution proposed here eliminates the problem of non-uniqueness of the optimal solution, which is present when this optimal control problem is solved using the recursive algorithm proposed by Chow,1 Pindyck2 and Tan.3 If a unique solution to the optimal control problem exists, then the direct solution and the recursive solution coincide. 相似文献
149.
The helicity of the tryptathionine moiety of the phallotoxins has been recognized by comparison with cyclic tryptathionine tripeptides. In order to investigate the influence of the configuration of the component amino acids on the conformation of the cyclic peptides, six analogue thioether tripeptides containing L- and D-alanine and L- and D-cysteine, respectively, have been synthesized. The CD spectra of the peptides are very similar to each other, showing mirror images of the CD of phalloidin and, therefore, negative helicity. The spectra of the D-cysteine containing compounds differ from the L-cysteine containing compounds by their weakly positive ellipticity values around 270 nm. The cyclization reaction of Boc-Hpi-D-Ala-D-Cys(STrt)OCH3, along with the cyclic tripeptide, afforded a cyclic hexapeptide by dimerization. The CD spectrum of the dimer is very similar to that of phalloidin, thus pointing to a positive helicity of its two tryptathionine moieties. The dimeric thioether peptide forms a rather strong complex with Cu2+ ions. 相似文献
150.
颅面部的 CT扫描检查主要包括颅脑面部上、下颌骨、中耳、内耳、鼻窦、眼眍、眼球及颞骨茎突等部位的扫描检查 ,上述部位的扫描检查的位置的摆法 ,层面的厚度、间距 ,扫描时间及螺距等参数的选择及扫描后图像的后处理工作对检查结果的诊断至关重要。上述参数任意一个选择不当及 相似文献