全文获取类型
收费全文 | 386篇 |
免费 | 52篇 |
国内免费 | 3篇 |
专业分类
儿科学 | 6篇 |
妇产科学 | 3篇 |
基础医学 | 106篇 |
口腔科学 | 6篇 |
临床医学 | 22篇 |
内科学 | 40篇 |
皮肤病学 | 2篇 |
神经病学 | 2篇 |
特种医学 | 29篇 |
外科学 | 19篇 |
综合类 | 3篇 |
预防医学 | 10篇 |
眼科学 | 10篇 |
药学 | 142篇 |
肿瘤学 | 41篇 |
出版年
2024年 | 1篇 |
2021年 | 4篇 |
2020年 | 1篇 |
2019年 | 4篇 |
2018年 | 6篇 |
2017年 | 7篇 |
2016年 | 6篇 |
2015年 | 4篇 |
2014年 | 6篇 |
2013年 | 9篇 |
2012年 | 13篇 |
2011年 | 14篇 |
2010年 | 10篇 |
2009年 | 12篇 |
2008年 | 18篇 |
2007年 | 7篇 |
2006年 | 15篇 |
2005年 | 8篇 |
2004年 | 14篇 |
2003年 | 8篇 |
2002年 | 12篇 |
2001年 | 10篇 |
2000年 | 10篇 |
1999年 | 14篇 |
1998年 | 16篇 |
1997年 | 16篇 |
1996年 | 12篇 |
1995年 | 8篇 |
1994年 | 2篇 |
1993年 | 6篇 |
1992年 | 13篇 |
1991年 | 7篇 |
1990年 | 9篇 |
1989年 | 20篇 |
1988年 | 16篇 |
1987年 | 11篇 |
1986年 | 28篇 |
1985年 | 12篇 |
1984年 | 9篇 |
1983年 | 9篇 |
1982年 | 5篇 |
1981年 | 3篇 |
1980年 | 7篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1977年 | 4篇 |
1976年 | 5篇 |
1975年 | 6篇 |
1970年 | 1篇 |
排序方式: 共有441条查询结果,搜索用时 765 毫秒
1.
2.
Solitary bronchioloalveolar carcinoma: CT criteria 总被引:14,自引:0,他引:14
Kuhlman JE; Fishman EK; Kuhajda FP; Meziane MM; Khouri NF; Zerhouni EA; Siegelman SS 《Radiology》1988,167(2):379-382
The computed tomographic (CT) scans of 30 patients with solitary bronchioloalveolar carcinoma were reviewed. Common features at CT included the peripheral or subpleural location of a pulmonary mass (25 cases), pseudocavitation (18 cases), heterogeneous attenuation (17 cases), irregular margins forming a star pattern (22 cases), and pleural tags (21 cases). Using these CT criteria, four independent observers attempted to identify cases of bronchioloalveolar carcinoma from a larger sample of lung cancers and benign lesions by categorizing a series of test cases into four probability categories. Although the bronchioloalveolar carcinomas were correctly ranked in the two highest probability categories 75% of the time (in 45 of 60 cases), there was considerable overlap with other lung lesions, particularly with adenocarcinoma and large cell undifferentiated carcinoma. However, even though the typical features of bronchioloalveolar carcinoma are not invariable or highly specific, they are characteristic enough to suggest the diagnosis. 相似文献
3.
J. Garssen H. Van Loveren C. M. Gierveld H. Van der Vliet F. P. Nijkamp 《British journal of pharmacology》1993,109(1):53-60
1. The effects of muscarinic receptor antagonists considered to be selective for M1 receptors (pirenzepine; PZ), M2 receptors (AFDX-116), and for M3 receptors (4-diphenyl acetoxy N-methyl-piperidine (4-DAMP)) were used to investigate the existence of muscarinic receptors subtypes in murine airways. Atropine was used as a nonselective antagonist. The effects of these antagonists were studied upon tracheal contractions induced either by EFS (electric field stimulation) or by application of an exogenous cholinoceptor agonist (arecoline). 2. The muscarinic receptor antagonists tested inhibited arecoline-induced tracheal contractions with the following rank order of potency: 4-DAMP = atropine > pirenzepine = AFDX-116. The rank order of potency of the muscarinic antagonists used in inhibiting EFS-induced tracheal contractions was: 4-DAMP = atropine > PZ > AFDX-116. The pA2 values for these antagonists were similar when compared to the pA2 values determined in guinea-pig and bovine airway smooth muscle. 3. In addition to in vitro studies, the effects of inhalation of the different muscarinic antagonists on lung function parameters in vivo were investigated. Inhalation of 4-DAMP induced a decrease in airway resistance and an increase in lung compliance. In contrast, inhalation of AFDX-116 induced an increase in airway resistance and almost no change in lung compliance. Apart from some minor effects of atropine on airway resistance, atropine, PZ, and pilocarpine failed to induce changes in lung mechanics as determined by in vivo lung function measurements. 4. The results provide evidence for the existence of M3 receptors on murine tracheae that are involved in the contraction of tracheal smooth muscle.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
4.
Identification of a gene disrupted by a microdeletion in a patient with X-linked retinitis pigmentosa (XLRP) 总被引:2,自引:2,他引:2
Roepman R; Bauer D; Rosenberg T; van Duijnhoven G; van de Vosse E; Platzer M; Rosenthal A; Ropers HH; Cremers FP; Berger W 《Human molecular genetics》1996,5(6):827-833
The gene for the most frequent from of X-linked retinitis pigmentosa
(XLRP), RP3, has been assigned by genetic and physical mapping to a segment
of less than 1000 kbp, which is flanked by the marker DXS1110 and the
ornithine transcarbamylase (OTC) gene. In search of microdeletions, we have
screened the DNA of 30 unrelated patients with XLRP by employing a
representative set of YAC-derived DNA fragments that were generated by
restriction enzyme digestion and PCR amplification. In one of these
patients, a 6.4 kbp microdeletion was detected which was not present in the
DNA of 444 male controls. A cosmid contig spanning the deletion was
constructed and used to isolate cDNAs from retina-specific libraries. Exons
corresponding to these expressed sequences as well as other putative exons
were identified by sequencing more than 30 kbp of the critical region. So
far, no point mutations in these putative exon sequences have been
identified.
相似文献
5.
Positional cloning of the gene for X-linked retinitis pigmentosa 3: homology with the guanine-nucleotide-exchange factor RCC1 总被引:6,自引:7,他引:6
Roepman R; van Duijnhoven G; Rosenberg T; Pinckers AJ; Bleeker-Wagemakers LM; Bergen AA; Post J; Beck A; Reinhardt R; Ropers HH; Cremers FP; Berger W 《Human molecular genetics》1996,5(7):1035-1041
The gene for retinitis pigmentosa 3 (RP3), the most frequent form of X-
linked RP (XLRP), has been mapped previously to a chromosome interval of
less than 1000 kbp between the DXS1110 marker and the OTC locus at
Xp21.1-p11.4. Employing a novel technique, YAC Representation Hybridization
(YRH)', we have recently identified a small XLRP associated microdeletion
in this interval, as well as several putative exons including the 3' end of
a gene that was truncated by the deletion. cDNA library screening and
sequencing of a cosmid centromeric to the deletion has now enabled us to
identify numerous additional exons and to detect several point mutations in
patients with XLRP. The predicted gene product shows homology to RCC1, the
guanine-nucleotide- exchange factor (GEF) of the Ras-like GTPase Ran. Our
findings suggest that we have cloned the long-sought RP3 gene, and that it
may encode the GEF of a retina-specific GTP-binding protein.
相似文献
6.
Bronchial hyperreactivity to histamine 4 days following vaccination with the human respiratory pathogenHaemophilus influenzae was tested in twoin vivo and onein vitro models. Conscious vaccinated guinea pigs exposed to aerosolized histamine became asphyxial significantly faster than saline-treated controls. Also the bronchoconstriction in anaesthetized guinea pigs as a result of i.v. histamine was significantly potentiated in theH. influenzae pretreated group. Isoprenaline (30g/kg) partially inhibited the bronchoconstriction. The difference in histamine sensitivity between the two groups however remained. Protection against bronchoconstriction by atropine on the other hand was significantly enhanced in the vaccinated animals. This suggests a hyperreactivity of the parasympathetic, cholinergic pathways as a result ofH. influenzae vaccination.To whom correspondence should be addressed. 相似文献
7.
8.
Guinea pigs were inoculated intra-tracheally with bovine parainfluenza type 3 virus (PI-3) to investigate airway responsiveness to histamine and arecolinein vitro. Two days after saline or PI-3 inoculation no difference in the reactivity of the tracheal spirals was observed after cumulative concentration/response curves with both drugs. Similarly, contractions of parenchymal strips, induced by histamine, did not differ between both groups. However, 4 days after PI-3 inoculation the histamine induced contraction of the tracheal spirals was increased by 47% and the arecolinc induced contractions by 32% as compared to the control group. Further, the contractions induced by histamine in parenchymal strips were significantly enhanced (p<0.01) in the PI-3 treated group. In conclusion, PI-3 infection of guinea pig respiratory tract induces hyperreactivity of the central and peripheral airwaysin vitro. 相似文献
9.
10.