全文获取类型
收费全文 | 9139篇 |
免费 | 595篇 |
国内免费 | 55篇 |
专业分类
耳鼻咽喉 | 128篇 |
儿科学 | 227篇 |
妇产科学 | 271篇 |
基础医学 | 1313篇 |
口腔科学 | 753篇 |
临床医学 | 785篇 |
内科学 | 2204篇 |
皮肤病学 | 264篇 |
神经病学 | 906篇 |
特种医学 | 115篇 |
外科学 | 795篇 |
综合类 | 52篇 |
一般理论 | 1篇 |
预防医学 | 844篇 |
眼科学 | 120篇 |
药学 | 510篇 |
中国医学 | 49篇 |
肿瘤学 | 452篇 |
出版年
2024年 | 14篇 |
2023年 | 145篇 |
2022年 | 274篇 |
2021年 | 496篇 |
2020年 | 284篇 |
2019年 | 417篇 |
2018年 | 443篇 |
2017年 | 287篇 |
2016年 | 328篇 |
2015年 | 411篇 |
2014年 | 489篇 |
2013年 | 587篇 |
2012年 | 833篇 |
2011年 | 849篇 |
2010年 | 449篇 |
2009年 | 341篇 |
2008年 | 611篇 |
2007年 | 508篇 |
2006年 | 384篇 |
2005年 | 393篇 |
2004年 | 294篇 |
2003年 | 292篇 |
2002年 | 200篇 |
2001年 | 62篇 |
2000年 | 55篇 |
1999年 | 59篇 |
1998年 | 33篇 |
1997年 | 20篇 |
1996年 | 16篇 |
1995年 | 13篇 |
1994年 | 12篇 |
1993年 | 6篇 |
1992年 | 25篇 |
1991年 | 19篇 |
1990年 | 18篇 |
1989年 | 18篇 |
1988年 | 11篇 |
1987年 | 15篇 |
1986年 | 10篇 |
1985年 | 11篇 |
1984年 | 7篇 |
1983年 | 3篇 |
1980年 | 4篇 |
1978年 | 5篇 |
1976年 | 4篇 |
1974年 | 8篇 |
1973年 | 5篇 |
1969年 | 3篇 |
1968年 | 3篇 |
1965年 | 2篇 |
排序方式: 共有9789条查询结果,搜索用时 15 毫秒
1.
2.
3.
F Carmona F Fábregues R Alvarez J Vila V Cararach 《European journal of obstetrics, gynecology, and reproductive biology》1992,45(1):67-70
Morganella morganii, a gram-negative bacterium, usually infects older patients with urinary catheters, but does not commonly affect pregnant women. In this report we present a case of chorioamnionitis caused by Morganella morganii. The case was complicated by a life-threatening Adult Respiratory Distress Syndrome. 相似文献
4.
Enrico Bertino Carolina Bisson Claudio Martano Alessandra Coscia Claudio Fabris Giovanna Monti Tiziana Testa Amedeo Conti 《Pediatric allergy and immunology》2006,17(7):484-488
AIM: A positive correlation between maternal and cord-blood IgE levels is well documented for total IgEs, but not for specific IgEs. The difficulty in detecting specific cord-blood IgEs is due to their low concentrations, which hinder their dosage by low-sensitivity methods. The study aimed to correlate maternal and foetal specific IgEs against individual cow's milk proteins, detected by highly sensitive and specific techniques. METHODS: Cow's milk specific IgE detection was performed by chemiluminescence on 52 specimens of maternal and cord blood after cow's milk protein separation by 1D and 2D gel electrophoresis. Cow's milk protein (CMP) antigens were identified by mass spectrometry techniques. RESULTS: Specific IgEs for CMPs were found in 25/52 (48.1%) of maternal sera and in 19/52 (37%) of cord-blood sera. In order of decreasing frequency, the proteins found were BSA, IgG heavy chain, caseins and, in a single case, b-lactoglobulin. Positive cord-blood sera in all cases corresponded to a positive maternal result, and maternal and foetal immunoreactivity patterns were closely correlated. Moreover, in no case was there a positive cord-blood response with a negative maternal response. CONCLUSION: The study demonstrates a close relationship between maternal and cord-blood specific IgE patterns. The phenomenon observed could provide a model to elucidate the general production method of foetal IgEs, which might only be produced in the presence of both the corresponding maternal IgE and the related allergen. 相似文献
5.
Involvement of clusterin and the aggresome in abnormal protein deposits in myofibrillar myopathies and inclusion body myositis 总被引:2,自引:0,他引:2
Ferrer I Carmona M Blanco R Moreno D Torrejón-Escribano B Olivé M 《Brain pathology (Zurich, Switzerland)》2005,15(2):101-108
Myofibrillar myopathies (MM) are characterized morphologically by the presence of non-hyaline structures corresponding to foci of dissolution of myofibrils, and hyaline lesions composed of aggregates of compacted and degraded myofibrillar elements. Inclusion body myositis (IBM) is characterized by the presence of rimmed vacuoles, eosinophilic inclusions in the cytoplasm, rare intranuclear inclusions, and by the accumulation of several abnormal proteins. Recent studies have demonstrated impaired proteasomal expression and activity in MM and IBM, thus accounting, in part, for the abnormal protein accumulation in these diseases. The present study examines other factors involved in protein aggregation in MM and IBM. Clusterin is a multiple-function protein which participates in Abeta-amyloid, PrP(res) and a-synuclein aggregation in Alzheimer disease, prionopathies and a-synucleinopathies, respectively. gamma-Tubulin is present in the centrosome and is an intracellular marker of the aggresome. Moderate or strong clusterin immunoreactivity has been found in association with abnormal protein deposits, as revealed by immunohistochemistry, single and double-labeling immunofluorescence and confocal microscopy, in MM and IBM, and in target structures in denervation atrophy. Gamma-Tubulin has also been observed in association with abnormal protein deposits in MM, IBM, and in target fibers in denervation atrophy. These morphological findings are accompanied by increased expression of clusterin and gamma-tubulin in muscle homogenates of MM and IBM cases, as revealed by gel electrophoresis and Western blots. Together, these observations demonstrate involvement of clusterin in protein aggregates, and increased expression of aggresome markers in association with abnormal protein inclusions in MM and IBM and in targets, as crucial events related to the pathogenesis of abnormal protein accumulation and degradation in these muscular diseases. 相似文献
6.
7.
Plasma glucose and lactate, hepatic glycogen and epididymal adipose tissue lipogenesis and lipolysis were studied in Wistar audiogenic rats (WARs), a genetic model of epilepsy, under three experimental conditions, i.e., before, 3 min after and 10 min after seizures induced by intense sound exposure. Plasma glucose increased 3 min after the seizure onset and rose to a peak after 10 min. Hepatic glycogen decreased significantly in susceptible audiogenic rats compared to nonepileptic controls, even before sound stimulation. A marked ( approximately 10-fold) rise was observed in plasma lactate levels 3 and 10 min after the seizures compared to the response of the control group. Lipogenic activity showed a marked decrease even after stimulation with 25 ng/ml insulin. Based on these results, WARs showed reduced isoproterenol-stimulated lipolysis compared to control animals, whereas basal levels only differed significantly at 10 min after seizure activity. In conclusion, it can be inferred from these results that (a) the increase in plasma glucose after stimulation might result from sequential interaction of autonomic activation at seizure onset; (b) excessive muscular activity was at least partially responsible for the steady rise in plasma lactate concentrations; (c) audiogenic seizures, which increase adrenergic activity, induce desensitization of the beta-adrenergic lipolytic pathway in epididymal adipose tissue; (d) genetic selection for audiogenic seizure susceptibility results in pronounced alterations at multiple levels of metabolic regulation. 相似文献
8.
Most copper bioleaching plants operate with a high concentration of sulfate salts, caused by the continuous addition of sulfuric acid and the recycling of the leaching solution. Since the bacteria involved in bioleaching have been generally isolated at low sulfate concentrations, the bacterial population present in the high-sulfate (150 gl(-1)) leaching solution, employed in a copper production plant, was investigated. The iron-oxidizing bacteria able to grow in the leaching solution were enriched by several batch cultivations and, after serial dilution, an abundant bacterial strain was isolated. This strain, called LA, exhibited a relatively constant rate of iron-oxidation in media containing sulfate ions at concentrations ranging from 10 to 150 gl(-1). Culture collection strains of Leptospirillum ferrooxidans and Acidithiobacillus ferrooxidans showed limited abilities to grow at sulfate ion concentrations higher than 70 gl(-1). In spite of its tolerance to high sulfate concentrations, strain LA was as sensitive to NaCl as A. ferrooxidans. Comparative sequence analysis of the 16S rRNA gene of strain LA indicated that it is phylogenetically related to strains described as Leptospirillum ferrooxidans. Bacterial community DNA restriction patterns of 16S rRNA genes suggested that strain LA was a minor component of the bacterial population present in leaching solution, but is abundant in ore leached with this solution. 相似文献
9.
Carolina Scagnolari Francesca Bellomi Ombretta Turriziani Francesca Bagnato Valentina Tomassini Vito Lavolpe Marilena Ruggieri Fabrizio Bruschi Giuseppe Meucci Giordano Dicuonzo Guido Antonelli 《Journal of interferon & cytokine research》2002,22(2):207-213
The frequencies of anti-interferon-beta (IFN-beta) antibody development reported to date in patients treated with different IFN-beta preparations are not readily comparable mainly because of differences in underlying diseases and assay methods. Thus, the frequency of neutralizing antibody (NAb) and binding antibody (BAb) development was analyzed in a sample of sera derived from a homogeneous group of relapsing-remitting multiple sclerosis (RRMS) patients treated with different IFN-beta preparations. The frequency of developing NAb and BAb to IFN-beta varied according to the IFN-beta given. Specifically, the NAb seroconversion frequency was significantly higher in patients treated with Betaferon, Schering AG, Berlin, Germany (31.3%) than in patients treated with both preparations of recombinant IFN-beta 1a (Rebif, Serono, Geneva, Switzerland [7.4%] or Avonex, Biogen, Cambridge, MA [6.3%]). Analysis of BAb seroconversion frequency in the same patients revealed that different IFN-beta preparations may also have different capability to induce BAb development and that BAb are produced during IFN-beta therapy at a significantly higher rate than NAb. Our main conclusion is that different human IFN-beta preparations may possess different immunogenicities, leading to varying frequency of development of antibody to IFN-beta in RRMS. 相似文献
10.
Scali C Prosperi C Bracco L Piccini C Baronti R Ginestroni A Sorbi S Pepeu G Casamenti F 《Neurobiology of aging》2002,23(4):523-530
To evaluate whether inflammation-like mechanisms present in the brain of Alzheimer's disease (AD) patients are reflected in the periphery, the expression of CD11b in peripheral blood neutrophils and the expression and activity of inflammatory markers in cultured skin fibroblasts were examined. We found significantly higher levels of CD11b in neutrophils from sporadic AD patients than in controls and this elevation was positively correlated with disease severity and progression rate of mental decline. Cultured skin fibroblasts from familial (FAD) and sporadic AD patients and from controls were immunopositive for both isoforms of cyclooxygenase with no differences between groups. In unstimulated culture, the production of prostaglandin-E2 in the medium was significantly higher in fibroblasts from sporadic AD and FAD patients than in controls, and this elevation was reverted by the addition of 25 microM of ibuprofen. Our findings provide further evidence of the presence of inflammatory and immuno-related markers in the periphery of AD patients and support those studies indicating the beneficial effects of anti-inflammatory therapy in AD. 相似文献