全文获取类型
收费全文 | 4756篇 |
免费 | 372篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 29篇 |
儿科学 | 95篇 |
妇产科学 | 55篇 |
基础医学 | 662篇 |
口腔科学 | 75篇 |
临床医学 | 632篇 |
内科学 | 1028篇 |
皮肤病学 | 120篇 |
神经病学 | 313篇 |
特种医学 | 202篇 |
外国民族医学 | 1篇 |
外科学 | 662篇 |
综合类 | 35篇 |
预防医学 | 381篇 |
眼科学 | 192篇 |
药学 | 330篇 |
中国医学 | 27篇 |
肿瘤学 | 298篇 |
出版年
2024年 | 8篇 |
2023年 | 59篇 |
2022年 | 131篇 |
2021年 | 276篇 |
2020年 | 151篇 |
2019年 | 167篇 |
2018年 | 170篇 |
2017年 | 155篇 |
2016年 | 131篇 |
2015年 | 135篇 |
2014年 | 178篇 |
2013年 | 196篇 |
2012年 | 315篇 |
2011年 | 334篇 |
2010年 | 182篇 |
2009年 | 173篇 |
2008年 | 287篇 |
2007年 | 298篇 |
2006年 | 252篇 |
2005年 | 237篇 |
2004年 | 183篇 |
2003年 | 175篇 |
2002年 | 141篇 |
2001年 | 123篇 |
2000年 | 106篇 |
1999年 | 99篇 |
1998年 | 31篇 |
1997年 | 33篇 |
1996年 | 24篇 |
1995年 | 12篇 |
1994年 | 18篇 |
1993年 | 13篇 |
1992年 | 46篇 |
1991年 | 29篇 |
1990年 | 29篇 |
1989年 | 53篇 |
1988年 | 20篇 |
1987年 | 30篇 |
1986年 | 17篇 |
1985年 | 22篇 |
1984年 | 11篇 |
1983年 | 10篇 |
1982年 | 7篇 |
1981年 | 10篇 |
1979年 | 9篇 |
1978年 | 10篇 |
1977年 | 10篇 |
1975年 | 5篇 |
1974年 | 12篇 |
1970年 | 3篇 |
排序方式: 共有5137条查询结果,搜索用时 15 毫秒
21.
Nathalie Sints-Zydowicz Quang Tho Pham Jacque Dubois Philippe Michaud 《Macromolecular chemistry and physics.》1997,198(7):2017-2026
In depth study of low molecular weight poly(imide-amide)s (PIA) obtained by copolycondensation of 4,4′-methylenedi(phenyl isocyanate), trimellitic anhydride and benzoic acid by 1H and 13C NMR spectroscopy and size-exclusion chromatography allows the determination of their absolute number-average molecular weights M?n, abs. Viscosimetric measurements reveal that, dissolved in N-methyl-2-pyrrolidone, these low molecular weight PIAs should be semi-rigid because of the presence of very short crystalline chains. By using the semi-empirical Fox-Flory relation, the extrapolated glass transition temperature equals 300°C for high molecular weight. 相似文献
22.
Han XY Pham AS Nguyen KU Smythe WR Ordonez NG Jacobson KL Tarrand JJ 《American journal of clinical pathology》2001,116(3):347-353
Pulmonary granuloma is a common lesion for which gram-negative bacteria are rarely implicated as a cause. Hence, most physicians are unaware of this etiology. We isolated a gram-negative bacterium from a surgically resected pulmonary granuloma in a 42-year-old, nonimmunocompromised woman. Within the necrotizing granuloma, numerous organisms also were demonstrated by Gram stain, suggesting a cause-disease relationship. Characterization of the bacterium by sequence analysis of the 16S ribosomal gene, cellular fatty acid profiling, and microbiologic studies revealed a novel bacterium with a close relationship to Pseudomonas. We propose a new species for the bacterium, Pseudomonas andersonii. These results suggest that the differential diagnosis of a lung granuloma also should include this gram-negative bacterium as a potential causative agent, in addition to the more common infections caused by acid-fast bacilli and fungi. This bacterium was shown to be susceptible to most antibiotics that are active against gram-negative bacteria. 相似文献
23.
Dien Pham Huy Monique Roch-Arveiller Monique Lenoir Olivier Muntaner Alain Thuret Jean-Paul Giroud 《Inflammation research》1986,18(3-4):366-371
The effect of piroxicam on rat polymorphonuclear leucocytes (PMN) has been studiedin vitro andin vivo after the induction of two acute, non specific inflammatory reactions (pleurisies induced by calcium pyrophosphate crystals (CaPP) or isologous serum).An inhibition of chemotaxis by piroxicam has been demonstrated by two techniques, the filter and agarose assaysin vivo andin vitro. An inhibition of random cell migration has been observed only at the higher drug concentration using agarose assay with CaPP-elicited cells.Piroxicam also inhibited superoxide anion generation and O2 consumption of CaPP- and serum-elicited cells.These findings suggest that piroxicam may have a direct effect on PMN responses and that this activity could, at least in part, contribute to its anti-inflammatory properties. 相似文献
24.
Wajid M Abbasi AA Ansar M Pham TL Yan K Haque S Ahmad W Leal SM 《European journal of human genetics : EJHG》2003,11(10):812-815
This article describes the identification of a novel locus (DFNB39) responsible for an autosomal recessive form of hearing loss segregating in a Pakistani consanguineous family. The hearing impaired members of this family present with profound prelingual sensorineural hearing impairment and use sign language for communications. Linkage was established to microsatellite markers located on chromosome 7q with a maximum multipoint lod score of 3.8. The region of homozygosity spans a 19 cM region that is bounded by markers D7S3046 and D7S644. 相似文献
25.
El Benna J Hayem G Dang PM Fay M Chollet-Martin S Elbim C Meyer O Gougerot-Pocidalo MA 《Inflammation》2002,26(6):273-278
Superoxide anion (O2°-)production by neutrophil NADPH oxidase participates in arthritic joint lesion formation. Proinflammatory cytokines such as tumor necrosis factor (TNF), interleukin 8 (IL-8) and granulocyte/macrophage-colony stimulating factor (GM-CSF) have a priming effect on neutrophil NADPH oxidase activity. NADPH oxidase activation is dependent on phosphorylation of p47phox, a cytosolic component of the enzyme. We studied O2°-production and p47phox phosphorylation in synovial fluid (SF) from patients with rheumatoid arthritis (RA) and spondylarthropathy (SpA) according to TNF, IL-8 and GM-CSF levels. O2°-production by neutrophils isolated from SF of all the arthritis patients (RA and SpA) was higher than that of circulating resting neutrophils and when stimulated with fMLP or PMA. In addition, p47phox was partially phosphorylated in SF neutrophils compared to circulating neutrophils. High levels of TNF and IL-8 (but not GM-CSF) are detected in patient's SF (compared to circulating blood levels). TNF levels were significantly higher in RA than in SpA SF. These results suggest that increased NADPH oxidase activity could be involved in arthritic joint inflammation through increased p47phox phosphorylation. This could be the result of the presence of high levels of priming agents such as TNF and IL-8 but not GM-CSF. 相似文献
26.
Jonathan D Darer Wenke Hwang Hoangmai H Pham Eric B Bass Gerard Anderson 《Academic medicine》2004,79(6):541-548
PURPOSE: Although more than 125 million North Americans have one or more chronic conditions, medical training may not adequately prepare physicians to care for them. The authors evaluated physicians' perceptions of the adequacy of their chronic illness care training to and the effects of training on their attitudes toward care of persons with chronic conditions. METHOD: In November 2000 through June 2001, the authors surveyed by telephone a random sample of U.S. physicians who had > or =20 hours of patient contact per week. The interview instrument examined demographics, career satisfaction, practice characteristics, perceived adequacy of chronic illness care training in ten competencies (geriatric syndromes, chronic pain, nutrition, developmental milestones, end-of-life care, psychosocial issues, patient education, assessment of caregiver needs, coordination of services, and interdisciplinary teamwork), and effect of training on attitudes toward chronic illness care. RESULTS: Of 1,905 eligible physicians, 1,236 (65%) responded (270 family or general practitioners, 231 internists, 129 pediatricians, 335 nonsurgical specialists, and 271 surgeons). Most physicians reported their chronic disease training was less than adequate for all ten competencies. Family practitioners were more likely (p <.05) to report adequate training in seven competencies compared with internists, and in two to four competencies when compared with pediatricians, nonsurgical specialists, or surgeons. Most physicians reported that training had a positive effect on attitudes toward care of people with chronic conditions, including the ability to make a difference in their lives (74-84%). CONCLUSIONS: Physicians perceived their medical training for chronic illness care was inadequate. Medical schools and residencies may need to modify curricula to better prepare physicians to treat the growing number of people with chronic conditions. 相似文献
27.
Pham MT Maitz MF Reuther H Muecklich A Prokert F Steiner G 《Journal of biomedical materials research. Part A》2004,71(1):16-24
The native extracellular matrix (ECM) laid down on silicon and titanium surfaces by osteoblast-like SAOS-2 cells was exposed by selective removal of cells. This type of material surface ECM-Si, ECM-Ti was shown to promote the nucleation of calcium phosphate from a simulated body fluid (SBF). Microscopic and spectroscopic results revealed the effect was associated with a collagen fiber-free extracellular matrix. 相似文献
28.
Myotonic dystrophy (DM) is a multisystemic disorder caused by an inherited CTG repeat expansion which affects three genes encoding the DM protein kinase (DMPK), a homeobox protein Six5 and a protein containing WD repeats. Using a panel of 16 monoclonal antibodies against several different DMPK epitopes we detected DMPK, as a single protein of approximately 80 kDa, only in skeletal muscle, cardiac muscle and, to a lesser extent, smooth muscle. Many earlier reports of DMPK with different sizes and tissue distributions appear to be due to antibody cross-reactions with more abundant proteins. One such antibody, MANDM1, was used to isolate two related protein kinases, MRCK alpha and beta, from a human brain cDNA library and the shared epitope was located at the catalytic site of DMPK using a phage-displayed random peptide library. The peptide library also identified an epitope shared between DMPK and a 55 kDa muscle-specific protein. The results suggest that effects of the repeat expansion on the DMPK gene may be responsible for muscle and heart features of DM, whereas clinical changes in other tissues may be due to effects on the other two genes. 相似文献
29.
The examination of H2O2-initiated hydroxytelechelic polybutadienes polymerized by H2O2 initiation by 1H NMR and 13C NMR allows the identification of three main primary alcoholic groups: α-unsaturated, β-substituted/α-unsaturated and γ-unsaturated. From 1H NMR accumulated spectra, it has been possible to calculate the number average OH-functionalities of the polymers. These should be slightly under-estimated because of the possible presence of secondary and tertiary alcoholic groups whose concentrations, however, should be very small. The nature of these alcohol functions gives information concerning the likely initiation, transfer and termination mechanisms of the radical polymerization of butadiene by H2O2 in alcoholic media. 相似文献
30.