全文获取类型
收费全文 | 47869篇 |
免费 | 2596篇 |
国内免费 | 165篇 |
专业分类
耳鼻咽喉 | 873篇 |
儿科学 | 1683篇 |
妇产科学 | 817篇 |
基础医学 | 6200篇 |
口腔科学 | 1073篇 |
临床医学 | 3689篇 |
内科学 | 11761篇 |
皮肤病学 | 1596篇 |
神经病学 | 4290篇 |
特种医学 | 1321篇 |
外科学 | 5898篇 |
综合类 | 221篇 |
一般理论 | 19篇 |
预防医学 | 4000篇 |
眼科学 | 1161篇 |
药学 | 2849篇 |
中国医学 | 146篇 |
肿瘤学 | 3033篇 |
出版年
2024年 | 49篇 |
2023年 | 336篇 |
2022年 | 479篇 |
2021年 | 1242篇 |
2020年 | 699篇 |
2019年 | 1308篇 |
2018年 | 1711篇 |
2017年 | 1139篇 |
2016年 | 1142篇 |
2015年 | 1299篇 |
2014年 | 1465篇 |
2013年 | 2040篇 |
2012年 | 3471篇 |
2011年 | 3761篇 |
2010年 | 1999篇 |
2009年 | 1634篇 |
2008年 | 3031篇 |
2007年 | 3203篇 |
2006年 | 2972篇 |
2005年 | 2923篇 |
2004年 | 2674篇 |
2003年 | 2528篇 |
2002年 | 2331篇 |
2001年 | 1194篇 |
2000年 | 1426篇 |
1999年 | 1107篇 |
1998年 | 314篇 |
1997年 | 243篇 |
1996年 | 212篇 |
1995年 | 152篇 |
1994年 | 112篇 |
1993年 | 96篇 |
1992年 | 361篇 |
1991年 | 267篇 |
1990年 | 234篇 |
1989年 | 172篇 |
1988年 | 168篇 |
1987年 | 172篇 |
1986年 | 126篇 |
1985年 | 120篇 |
1984年 | 95篇 |
1983年 | 75篇 |
1982年 | 31篇 |
1981年 | 40篇 |
1980年 | 35篇 |
1979年 | 63篇 |
1976年 | 33篇 |
1974年 | 34篇 |
1973年 | 41篇 |
1972年 | 32篇 |
排序方式: 共有10000条查询结果,搜索用时 1 毫秒
71.
M. Alcalde G. Jim��nez P. D��az M. Garc��a-D��az J. M. Pascasio R. Moro J. Zapata A. L��pez-Santamar��a 《Postgraduate medical journal》1997,73(859):295-296
A debilitated patient with liver cirrhosis and poor haemostasis had a severe lower gastrointestinal haemorrhage. A superior mesenteric arteriogram revealed an early persistent and promiment draining vein in the ileocolic artery. Two fragments of Spongostan and silk were used to embolise the bleeding artery and the haemorhage ceased immediately. No infarction of the embolised area was observed and the bleeding was controlled. 相似文献
72.
73.
Ruth Ladurner Gerald Brandacher Wolfgang Steurer Stefan Schneeberger Claudia Bösmüller Martin Clemens Freund Alfons Kreczy Alfred Königsrainer Raimund Margreiter 《Transplant international》2003,16(12):885-889
Fungal infections still represent a serious complication after organ transplantation. Early diagnosis and aggressive treatment are crucial. Because of the many diagnostic problems involved, we present a case of mucormycosis--primarily affecting the paranasal sinuses with later intracranial extension--in a highly immunized recipient of a third renal transplant. Although fungal infection was suspected from various imaging techniques, only the detection of typical fungal hyphae in the infected tissue was diagnostic. Neither the blood tests and cerebrospinal fluid examinations performed nor cultures from maxillary sinus fluid were of any diagnostic help. Surgical debridement from a transnasal as well as an intracranial approach and systemic amphotericin B together with the discontinuation of immunosuppression after removal of the rejected graft were able to save the patient. This case stresses the importance of early diagnosis that can only be made from tissue biopsies and allows appropriate timely treatment. 相似文献
74.
75.
76.
The activity from 55 septohippocampal neuron pairs was examined in rats anesthetized with urethane. In addition to the statistical characterization of the firing patterns of the recorded units, the functional interactions between pairs of neurons and between neurons and hippocampal theta (theta) waves were investigated with cross-correlation techniques. Pairs were classified according to the rhythmic or non-rhythmic discharge pattern of their neurons. (a) theta-Pairs were those in which both the medial septal (MS) and hippocampal (HPC) units were rhythmic (type 1 units). (b) Pairs with a rhythmic and a theta-related non-rhythmic unit (type 2 unit) were called mixed pairs. (c) Pairs composed of type 2 units were called type 2 pairs. theta-Pairs showed periodic cross-correlations and frequently fired with a phase difference which could change in different pairs. Mixed pairs also showed periodic cross-correlations although one of the units was non-rhythmic. Type 2 pairs showed non-periodic positive cross-correlations. Our data provide new information regarding the temporal relationship between MS and HPC rhythmic activities supporting the role of the MS in providing the afferent timing for the generation of theta-rhythm in the HPC. 相似文献
77.
J C Marvizón J Vázquez M García Calvo F Mayor A Ruíz Gómez F Valdivieso J Benavides 《Molecular pharmacology》1986,30(6):590-597
The displacement by glycine of 3H-strychnine binding to rat spinal cord membranes cannot be explained by a simple competitive interaction. Indeed, protein-modifying reagents can completely abolish the inhibition of 3H-strychnine binding by glycine and other agonists, whereas the interaction of strychnine itself and other related compounds with the binding site is unimpaired. Moreover, glycine cannot inhibit completely saturable 3H-strychnine binding, the extent of its maximum inhibitory effect depending on the ionic composition of the medium. Hill coefficients less than 1 (whose magnitude also depends on the assay medium) were obtained from glycine displacement curves. These properties are consistent with a mathematical model of two different, but mutually interacting, binding sites for strychnine and glycine on the glycine receptor. The effect of ions and protein-modifying reagents might be explained in this model as modifications of the mechanisms that mediate the allosteric interaction, and/or the affinity of glycine for the receptor. The agonists beta-alanine and taurine and the new antagonists, THAZ, iso-THAZ, and 4,5-TAZA, also seem to interact with a site different from the strychnine-binding site, probably the glycine-binding site. 相似文献
78.
Rafael T Mikolajczyk Maren Bredehorst Nadia Khelaifat Claudia Maier Annette E Maxwell 《BMC public health》2007,7(1):21
Background
The prevalence of depression is increasing not only among adults, but also among adolescents. Several risk factors for depression in youth have been identified, including female gender, increasing age, lower socio-economic status, and Latino ethnic background. The literature is divided regarding the role of acculturation as risk factor among Latino youth. We analyzed the correlates of depressive symptoms among Latino and Non-Latino White adolescents residing in California with a special focus on acculturation. 相似文献79.
Henryk Barthel Michael Wiener Claudia Dannenberg Simone Bettin Bernhard Sattler Wolfram H. Knapp 《European journal of nuclear medicine and molecular imaging》1997,24(10):1245-1252
This study addresses the question of whether the normal range for distribution of local cerebral blood flow (lCBF) in adults
can be transferred to the 4- to 15-year-old age group. Twenty-three children (age: 4–15 years; mean 11±3 years, group I) and
10 adults (age: 27–56 years; mean 45±10 years, group II) without evidence of cerebrovascular disease or other brain diseases
underwent technetium-99m ethyl cysteinate dimer single-photon emission tomography. Counts in cortical and subcortical regions
of interest (ROIs) were related to those in cerebellar ROIs (= 100%). Relative cortical activity in group I exceeded that
in group II, particularly in left parietal (107.6%±9.8% vs 84.1%±12.4%), left frontal (97.7%±6.7% vs 79.4%±8.9%) and left
temporal areas (99.7%±7.4% vs 84.9%±10.1%) and in the cingulate cortex (112.1%±9.1% vs 95.9%±10.1%, P<0.05). Cerebral activity uptake per injected dose was inversely correlated with age in 19 children of group I (r = –0.77, P<0.001). In group I, there was also an inverse correlation between age and the relative local count density in the parietal
(r = –0.42 to –0.57), frontal (r = –0.48), temporal (r = –0.42 to –0.58) and occipital cortex (r = –0.44). In these cortical regions relative counts differed when subgroups of children aged 4–10 and 11–15 years were analysed.
It is concluded that there are systematic differences between 4- to 15-year-old children and adults with regard to normal
lCBF. Diagnostic use of perfusion agents has to consider age-adjusted normal flow maps; normal ranges should be determined
separately for the age groups 4–10 and 11–15 years.
Received 23 March and in revised form 11 July 1997 相似文献
80.
Sporozoites and free circumsporozoite (CS) protein were stained immunoenzymatically in 1-min saliva samples collected fromAnopheles stephensi mosquitoes infected with eitherPlasmodium berghei orP. falciparum. The number of sporozoites in 1-min saliva-streak samples significantly increased as the salivary gland index rose from 3+ to 4+. ForP. berghei-infected mosquitoes from which saliva had been collected before 30 days postfeed, the median sporozoite counts for 3+ and 4+ gland indexes were 4.5 and 116, respectively. ForP. falciparum-infected mosquitoes, the median counts obtained in two experiments were 4.5 and 14.5 (3+) and 97 and 107 (4+), respectively. The frequency of sporozoite detection in the saliva of mosquitoes containing <100 salivary-gland sporozoites was low (0.1), whereas that in the saliva of mosquitoes with >100 sporozoites was high (0.96). In highly infected 4+P. berghei-infected mosquitoes from which saliva had been collected after 30 days postinfection, both the volume of saliva collected and the median number of sporozoites recovered decreased significantly. 相似文献