全文获取类型
收费全文 | 1798篇 |
免费 | 150篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 13篇 |
儿科学 | 32篇 |
妇产科学 | 12篇 |
基础医学 | 257篇 |
口腔科学 | 23篇 |
临床医学 | 193篇 |
内科学 | 578篇 |
皮肤病学 | 14篇 |
神经病学 | 169篇 |
特种医学 | 46篇 |
外科学 | 256篇 |
综合类 | 13篇 |
预防医学 | 107篇 |
眼科学 | 8篇 |
药学 | 109篇 |
肿瘤学 | 127篇 |
出版年
2023年 | 25篇 |
2022年 | 25篇 |
2021年 | 46篇 |
2020年 | 42篇 |
2019年 | 53篇 |
2018年 | 71篇 |
2017年 | 50篇 |
2016年 | 47篇 |
2015年 | 58篇 |
2014年 | 60篇 |
2013年 | 91篇 |
2012年 | 132篇 |
2011年 | 140篇 |
2010年 | 75篇 |
2009年 | 80篇 |
2008年 | 125篇 |
2007年 | 124篇 |
2006年 | 132篇 |
2005年 | 124篇 |
2004年 | 102篇 |
2003年 | 97篇 |
2002年 | 75篇 |
2001年 | 23篇 |
2000年 | 18篇 |
1999年 | 22篇 |
1998年 | 17篇 |
1997年 | 12篇 |
1996年 | 7篇 |
1995年 | 12篇 |
1994年 | 9篇 |
1993年 | 3篇 |
1992年 | 4篇 |
1991年 | 4篇 |
1990年 | 5篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 5篇 |
1986年 | 8篇 |
1985年 | 2篇 |
1984年 | 3篇 |
1983年 | 5篇 |
1982年 | 2篇 |
1980年 | 4篇 |
1979年 | 3篇 |
1977年 | 2篇 |
1975年 | 1篇 |
1974年 | 2篇 |
1973年 | 1篇 |
1968年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有1957条查询结果,搜索用时 0 毫秒
41.
The US Food and Drug Administration developed the Breakthrough Therapy designation to expedite the development and review of drugs that show a clear advantage over available therapy for serious conditions. Prior research has shown that physicians tend to misunderstand that a drug may receive a Breakthrough Therapy designation based on preliminary clinical evidence (eg, effect on a surrogate endpoint or intermediate clinical endpoint that is likely to predict clinical benefit). The objective of this article is to examine whether physicians’ familiarity with and interpretation of the Breakthrough Therapy designation have changed since a survey on the topic was published in 2016. We replicated three of the questions in that study and explored beliefs that a Breakthrough Therapy designation automatically qualifies a drug for accelerated approval. We also draw comparisons by specialization (oncologists vs. primary care physicians). In general, physicians remain more likely than not to misunderstand the Breakthrough Therapy designation. 相似文献
42.
Validation of the HFA‐PEFF score for the diagnosis of heart failure with preserved ejection fraction
43.
Prospective evaluation of the effect of deferasirox on hematologic response in transfusion‐dependent patients with low‐risk MDS and iron overload 下载免费PDF全文
44.
45.
Does taking endurance into account improve the prediction of weaning outcome in mechanically ventilated children? 总被引:1,自引:0,他引:1 下载免费PDF全文
Noizet O Leclerc F Sadik A Grandbastien B Riou Y Dorkenoo A Fourier C Cremer R Leteurtre S 《Critical care (London, England)》2005,9(6):R798-R807
Introduction
We conducted the present study to determine whether a combination of the mechanical ventilation weaning predictors proposed by the collective Task Force of the American College of Chest Physicians (TF) and weaning endurance indices enhance prediction of weaning success. 相似文献46.
47.
Helicobacter hepaticus hydrogenase mutants are deficient in hydrogen-supported amino acid uptake and in causing liver lesions in A/J mice 总被引:1,自引:0,他引:1 下载免费PDF全文
Helicobacter hepaticus, a causative agent of chronic hepatitis and hepatocellular carcinoma in mice, expresses a nickel-containing hydrogen-oxidizing hydrogenase enzyme. Growth of a hyaB gene-targeted mutant was unaffected by the presence of hydrogen, unlike the wild-type strain, which showed an enhanced growth rate when supplied with H(2). Hydrogenase activities in H. hepaticus were constitutive and not dependent on the inclusion of H(2) during growth. Addition of nickel during growth significantly stimulated both urease (for wild-type and hyaB) and hydrogenase (for wild-type) activities. In a 5-h period, the extent of (14)C-labeled amino acid uptake by the wild type was markedly enhanced in the presence of hydrogen and was >5-fold greater than that of the hyaB mutant strain. In the presence of H(2), the short-term whole-cell amino acid uptake V(max) of the parent strain was about 2.2-fold greater than for the mutant, but the half-saturation affinity for amino acid transport was the same for the parent and mutant strain. The liver- and cecum-colonizing abilities of the strains was estimated by real-time PCR quantitation of the H. hepaticus-specific cytolethal distending toxin gene and showed similar animal colonization for the hyaB mutant and the wild type. However, at 21 weeks postinoculation, the livers from mice inoculated with wild type exhibited moderate lobular lymphoplasmacytic hepatitis with hepatocytic coagulative necrosis, but the hydrogenase mutants exhibited no histological evidence of lobular inflammation or necrosis. 相似文献
48.
49.
Genomic studies of multiple myeloma reveal an association between X chromosome alterations and genomic profile complexity 下载免费PDF全文
50.
Mazieres S Callegari-Jacques SM Crossetti SG Dugoujon JM Larrouy G Bois E Crubezy E Hutz MH Salzano FM 《Annals of human biology》2011,38(1):76-83
Background: Previous investigations of French Guiana Amerindians performed by this group included blood group and protein genetic markers, mitochondrial DNA and Y-chromosome investigations. Molecular autosomal data and more extensive Y-chromosome determinations were lacking. Subjects and methods: The genetic variability of 15 autosome (ASTRs) and 17 Y-chromosome (YSTRs) microsatellite loci was studied in four French Guiana (Emerillon, Palikur, Wayampi, Kali'na) and one Brazilian (Apalai) Amerindian populations. A sixth group, the Peruvian Matsiguenga of the Maipurean linguistic family, was included in the data analysis since they could provide information about the past migration of people from that linguistic stock into northeastern Amazonia. Results: Marked ASTR and YSTR variability was found, with 96% of the YSTR haplotypes being found in one population only. There was excellent agreement between the present and previous autosomal or uniparental results. Multidimensional scaling based on F(ST) genetic distances and population structure analysis revealed heterogeneity in gene distribution, with a clear difference between the Matsiguenga and Emerillon and the other groups. In the latter, Wilcoxon sign-rank test between observed and expected heterozygosity and the mode of allele frequency distribution revealed clues of a significant past genetic bottleneck. The Wayampi stand genetically closer to the Apalai, Palikur and Kali'na when examined for the autosome but not the Y-chromosome panel of markers, suggesting preferential female gene flow. Conclusion: The new data provided additional important information about the biological history of people from a remote South American region, indicating how gene diversity analyses can be used to increase understanding of human microevolutionary processes. 相似文献