全文获取类型
收费全文 | 22807篇 |
免费 | 1279篇 |
国内免费 | 707篇 |
专业分类
耳鼻咽喉 | 138篇 |
儿科学 | 729篇 |
妇产科学 | 397篇 |
基础医学 | 3734篇 |
口腔科学 | 405篇 |
临床医学 | 1315篇 |
内科学 | 4471篇 |
皮肤病学 | 437篇 |
神经病学 | 1330篇 |
特种医学 | 365篇 |
外国民族医学 | 5篇 |
外科学 | 2053篇 |
综合类 | 2502篇 |
预防医学 | 1869篇 |
眼科学 | 244篇 |
药学 | 2520篇 |
3篇 | |
中国医学 | 731篇 |
肿瘤学 | 1545篇 |
出版年
2023年 | 183篇 |
2022年 | 429篇 |
2021年 | 588篇 |
2020年 | 470篇 |
2019年 | 1024篇 |
2018年 | 907篇 |
2017年 | 698篇 |
2016年 | 549篇 |
2015年 | 595篇 |
2014年 | 997篇 |
2013年 | 1173篇 |
2012年 | 972篇 |
2011年 | 1123篇 |
2010年 | 898篇 |
2009年 | 919篇 |
2008年 | 956篇 |
2007年 | 991篇 |
2006年 | 902篇 |
2005年 | 802篇 |
2004年 | 780篇 |
2003年 | 699篇 |
2002年 | 599篇 |
2001年 | 547篇 |
2000年 | 417篇 |
1999年 | 373篇 |
1998年 | 329篇 |
1997年 | 318篇 |
1996年 | 271篇 |
1995年 | 247篇 |
1994年 | 197篇 |
1993年 | 134篇 |
1992年 | 141篇 |
1991年 | 112篇 |
1990年 | 103篇 |
1989年 | 80篇 |
1988年 | 84篇 |
1987年 | 65篇 |
1985年 | 362篇 |
1984年 | 511篇 |
1983年 | 362篇 |
1982年 | 407篇 |
1981年 | 382篇 |
1980年 | 314篇 |
1979年 | 282篇 |
1978年 | 271篇 |
1977年 | 210篇 |
1976年 | 283篇 |
1975年 | 211篇 |
1974年 | 200篇 |
1973年 | 186篇 |
排序方式: 共有10000条查询结果,搜索用时 11 毫秒
41.
Hepatitis E in the south west of France in individuals who have never visited an endemic area 总被引:13,自引:0,他引:13
Mansuy JM Peron JM Abravanel F Poirson H Dubois M Miedouge M Vischi F Alric L Vinel JP Izopet J 《Journal of medical virology》2004,74(3):419-424
A total of 431 consecutive patients from the Midi Pyrenees area with acute hepatitis with unknown etiology in 2001-2002 were tested for the presence of immunoglobulin G-class (IgG) anti-hepatitis E virus (HEV) antibodies. Forty-six (10.7%) had anti-HEV IgG, and the results were questionable for a further 17 (3.9%). Real time PCR based on TaqMan detection was used to identify HEV genome fragments in the serum of patients with positive or questionable anti-HEV serology. HEV RNA was found in 25.4% of cases. All amplification products were sequenced and analyzed. Phylogenetic analysis revealed that all the strains were genotype 3. In conclusion, virological and epidemiological data indicate that genotype 3 viruses are circulating in the south west part of France (Midi-Pyrenees) in patients with acute hepatitis and who have not visited recently areas in which HEV is endemic. 相似文献
42.
Maria L. Dentici Vittorio Maglione Emanuele Agolini Gino Catena Rossella Capolino Valentina Lanari Antonio Novelli Lorenzo Sinibaldi Davide Vecchio Michaela V. Gonfiantini Marina Macchiaiolo Maria C. Digilio Bruno Dallapiccola Andrea Bartuli 《American journal of medical genetics. Part A》2020,182(8):1977-1984
The tubulinopathies refer to a wide range of brain malformations caused by mutations in one of the seven genes encoding different tubulin's isotypes. The β‐tubulin isotype III (TUBB3) gene has a primary function in nervous system development and axon generation and maintenance, due to its neuron‐specific expression pattern. A recurrent heterozygous mutation, c.1228G > A; p.E410K, in TUBB3 gene is responsible of a rare disorder clinically characterized by congenital fibrosis of the extraocular muscle type 3 (CFEOM3), intellectual disability and a wide range of neurological and endocrine abnormalities. Other mutations have been described spanning the entire gene and genotype–phenotype correlations have been proposed. We report on a 3‐year‐old boy in whom clinical exome sequencing allowed to identify a de novo TUBB3 E410K mutation as the molecular cause underlying a complex phenotype characterized by a severe bilateral palpebral ptosis refractory to eye surgery, psychomotor delay, absent speech, hypogonadism, celiac disease, and cyclic vomiting. Brain MRI revealed thinning of the corpus callosum with no evidence of malformation cortical dysplasia. We reviewed available records of patients with TUBB3 E410K mutation and compared their phenotype with the clinical outcome of patients with other mutations in TUBB3 gene. The present study confirms that TUBB3 E410K results in a clinically recognizable phenotype, unassociated to the distinct cortical dysplasia caused by other mutations in the same gene. Early molecular characterization of TUBB3 E410K syndrome is critical for targeted genetic counseling and prompt prospective care in term of neurological, ophthalmological, endocrine, and gastrointestinal follow‐up. 相似文献
43.
W C Light R E Reisman V S Ilea J I Wypych T Okazaki C E Arbesman 《The Journal of allergy and clinical immunology》1976,58(2):322-329
The antigenic and allergenic properties of phospholipase A2 (PLA2) and whole bee venom were compared by measuring the IgG and IgE antibody responses in animals and man. Precipitating antibodies raised in rabbits and reaginic and other antibodies raised in mice reacted about equally with both bee venom and PLA. The majority of human sera containing bee venom-specific IgE also contained PLA-specific IgE, although in somewhat lower titers. Similarly, most human sera with significant amounts of total antibodies reacting with bee venom also had antibodies reacting with PLA. Histamine and SRS-a release from leukocytes of sensitive patients followed challenge with whole bee venom and PLA in the majority of instances. However, mediator release from several patients' cells was obtained with bee venom only. These studies suggest that although PLA is a major allergen and antigen in bee venom, significant exceptions in patients' reactivity may limit its potential diagnostic and therapeutic usefulness. 相似文献
44.
Association between HLA and Japanese patients with rheumatoid arthritis 总被引:12,自引:0,他引:12
N Ohta Y K Nishimura K Tanimoto Y Horiuchi C Abe Y Shiokawa T Abe M Katagiri T Yoshiki T Sasazuki 《Human immunology》1982,5(2):123-132
Japanese patients with rheumatoid arthritis (RA) were observed to have a statistical association with HLA-DR4, MT3. Strong association between the clinical severity of RA and HLA was also observed. Male patients had a stronger association with HLA than female patients. Males are more resistant to RA than females. This suggested that the threshold of liability for RA is higher in males than in females. Japanese patients with RA with systemic vasculitis were negative for HLA-Bw44 and had antilymphocytotoxic autoantibody, indicating that RA with systemic vasculitis is different in etiology from RA without systemic vasculitis. 相似文献
45.
Helen G. Morris M.D. Ittai Neuman M.D. Elliot F. Ellis M.D. 《The Journal of allergy and clinical immunology》1974,54(6):350-358
Plasma steroid concentrations were measured in asthmatic children 24 and 48 hours after administration of alternate-day treatment with prednisone, and the results were compared with those of control patients who did not receive corticosteroid treatment as well as those of patients who were treated with prednisone each day. It was found that 24 hours after administration of prednisone in any dose, plasma steroid concentrations were significantly lower than those of the control group. The degree of suppression in plasma steroid concentration was less marked in patients who received treatment on alternate days than in those who received the same doses of prednisone each day. Within 48 hours after administration of alternate-day treatment, plasma steroid concentrations approached the values observed in the control group and were independent of the magnitude of the prednisone dose. Although alternateday steroid treatment was associated with transient and incomplete suppression of pituitary-adrenal function, patients whose therapy was changed from a daily to an alternate-day regimen sometimes exhibited prolonged suppression of adrenal cortical function. 相似文献
46.
Robert E. Reisman Mary Lazell Jean Doerr 《The Journal of allergy and clinical immunology》1981,68(5):406-408
This case report demonstrates the lack of correlation between clinical sensitivity to insect venoms and immunologic reactivity as indicated by the presence of venom-specific IgE. A 20-yr-old venom collector was monitored over a 3-yr period with measurements of venom-specific IgE (skin test and RAST) and venom-specific IgG. In the first year of venom collection, multiple stings were tolerated with no reaction. In the second season, she had an anaphylactic reaction after a yellow jacket sting. Subsequently, there was a rising titer of serum yellow jacket and bee venom-specific IgE and positive skin-test reactions. In the third season, yellow jacket, hornet, and bee venom skin tests remained positive and serum IgE antibody titers remained elevated. Stings from all three insects were tolerated with no reaction. Throughout the 3-yr course, serum venom-specific IgG remained low and unchanged. The factors other than IgE-modulating clinical anaphylaxis, perhaps responsible for this clinical and immunologic dichotomy, are unknown. These observations add a further complication to the choice of patients for venom immunotherapy. 相似文献
47.
Behavioral and neurochemical effects induced by subchronic combined exposure to toluene at 40 ppm and noise at 80 dB-A in rats 总被引:1,自引:0,他引:1
We investigated whether exposure to noise, in addition to its well-known potentiating effect on toluene-induced ototoxicity, may also exacerbate behavioral disturbances and brain neurochemical alterations produced by subchronic exposure to low toluene concentration. To test this hypothesis, we evaluated whether subchronic combined exposure (16 weeks, 104 h per week) to noise at 80 dB-A and toluene at 40 ppm potentiates the recently reported neurotoxic effects of subchronic exposure to 40 ppm toluene. Locomotor and rearing activities, sensitization to narcosis induced by acute toluene at high concentration, and tyrosine and tryptophan hydroxylase activities in the caudate-putamen and hippocampus were investigated in both male and female rats. Our results confirm that subchronic exposure to 40 ppm toluene significantly decreases rearing activity and leads to a sensitization to toluene-induced narcosis, as evaluated by loss of righting reflex, but fails to demonstrate any adverse effect of noise, alone or in combination with toluene. Given that toluene has addictive properties, the lack of potentiating behavioral and neurochemical effect of noise is discussed with regards to a recent study that has shown that methamphetamine neurotoxicity is potentiated by exposure to loud noise. 相似文献
48.
A series of cards each containing a two dimensional array of identical Snellen "E's" was used to determine best eccentric visual acuity in patients with macular disease having Snellen visual acuity of 20/70 or worse. Each "full field E" card simultaneously presents the same letter to foveal and parafoveal areas. This test can therefore determine quickly if potentially useful vision is present in any area of the central visual field. In our study of 37 eyes, 70% demonstrated potential visual acuity at least two times better than visual acuity measured by conventional methods, and 20% demonstrated at least a fourfold improvement. This suggests that most patients with macular disease do not spontaneously employ their best remaining area of retina for fixation. 相似文献
49.
W. von der Hude M. Scheutwinkel-Reich R. Braun W. Dittmar 《Archives of toxicology》1985,56(4):267-271
Valepotriates are epoxide-bearing triesters of the monoterpene alcohol 4,7-dimethylcyclopenta-(c)-pyrane isolated from the roots of several Valerianacae species. They are regarded as the main tranquilizing constituents of these drugs.Although the valepotriates valtrate/isovaltrate (VAL) and dihydrovaltrate (DH-VAL) showed a strong alkylating activity against the nucleophilic agent 4-(p-nitrobenzyl)-pyridine (NBP), they were not clearly mutagenic for the strains TA98, TA100, TA1535, and TA1537 of Salmonella typhimurium or for the strains WP2 and WP2 uvrA– of Escherichia coli in the absence of a metabolic activation system (S9-mix). However, the valepotriates were mutagenic for TA100, WP2 and WP2 uvrA– at concentrations up to about 1.0 mole/plate when S9-mix was added to the test system. With more than 1 mole/plate the valepotriates were toxic in the presence of a metabolic activation system for all strains tested. The mutagenicity of the valepotriates was inversely related to the protein content of the S9-mix used. The mutagenicity and toxicity of the valepotriates could be inhibited when the S9-mix was preincubated with the esterase inhibitor paraoxon (1 mM) for 5 min before the test compounds and bacteria were added. Therefore, bioactivation of the valepotriates by an enzymatic hydrolysis of their ester groups is considered. This could be proven by activating the valepotriates with purified esterase.Parts of this paper were presented at the Congress, Fortschritte in der Arzneimittelforschung, April 17–20, 1983 in Munich 相似文献
50.
E Libman W Brender R Burstein S Hodgins 《Journal of behavior therapy and experimental psychiatry》1984,15(2):127-131
Three theoretical formulations of ejaculatory incompetence have been proposed in the literature. They include: (1) aversive conditioned inhibition of the ejaculatory reflex, (2) an "autosexual" orientation associated with discrepant levels in the cognitive and physiological dimensions of sexual arousal, and (3) a discriminative learning model. These three models are discussed in relation to their theoretical and therapeutic implications. Clinical data supporting the discriminative view is presented. 相似文献