全文获取类型
收费全文 | 2459篇 |
免费 | 158篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 36篇 |
儿科学 | 63篇 |
妇产科学 | 92篇 |
基础医学 | 344篇 |
口腔科学 | 99篇 |
临床医学 | 150篇 |
内科学 | 440篇 |
皮肤病学 | 63篇 |
神经病学 | 282篇 |
特种医学 | 83篇 |
外科学 | 305篇 |
综合类 | 2篇 |
一般理论 | 2篇 |
预防医学 | 197篇 |
眼科学 | 120篇 |
药学 | 170篇 |
中国医学 | 5篇 |
肿瘤学 | 170篇 |
出版年
2023年 | 25篇 |
2022年 | 21篇 |
2021年 | 77篇 |
2020年 | 28篇 |
2019年 | 54篇 |
2018年 | 97篇 |
2017年 | 55篇 |
2016年 | 78篇 |
2015年 | 68篇 |
2014年 | 93篇 |
2013年 | 128篇 |
2012年 | 183篇 |
2011年 | 216篇 |
2010年 | 102篇 |
2009年 | 86篇 |
2008年 | 170篇 |
2007年 | 164篇 |
2006年 | 174篇 |
2005年 | 149篇 |
2004年 | 118篇 |
2003年 | 108篇 |
2002年 | 108篇 |
2001年 | 28篇 |
2000年 | 25篇 |
1999年 | 19篇 |
1998年 | 13篇 |
1997年 | 18篇 |
1996年 | 10篇 |
1995年 | 4篇 |
1994年 | 4篇 |
1992年 | 10篇 |
1991年 | 11篇 |
1990年 | 19篇 |
1989年 | 7篇 |
1988年 | 11篇 |
1987年 | 5篇 |
1986年 | 9篇 |
1985年 | 12篇 |
1983年 | 4篇 |
1982年 | 4篇 |
1979年 | 4篇 |
1967年 | 4篇 |
1935年 | 4篇 |
1933年 | 8篇 |
1932年 | 8篇 |
1931年 | 5篇 |
1930年 | 4篇 |
1929年 | 4篇 |
1928年 | 4篇 |
1923年 | 5篇 |
排序方式: 共有2623条查询结果,搜索用时 15 毫秒
71.
Rabellino M Aragón-Sánchez J González G Zander T Baldi S Garcia-Nielsen L Armas-Suarez S Barbero P Luis-Rodríguez D Maynar M 《Diabetes research and clinical practice》2010,90(3):e79-e81
To present the outcomes of endovascular treatment of diabetics patients with critical limb ischemia who have end-stage renal disease. Limb-salvage was achieved in 58.6% of the limbs during a mean follow-up period of 12.4 months. No major amputations were required on patients with rest pain or with grade 1 lesions. 相似文献
72.
Years of speculations about the nature of the elusive testis determining factor (TDF) of the Y chromosome have ended last year. A gene named SRY satisfies many criteria expected of the testis determining gene, and gives us a basis to understand molecular mechanisms of the testis differentiation. The different steps which gave rise to SRY cloning are described. 相似文献
73.
An accession of Vitis vinifera cv. Red Globe from Argentina, was found to be infected with Grapevine leafroll-associated virus-5 by ELISA. It was partially sequenced, and three ORFs, corresponding to HSP70h, HSP90h, and CP, were found. This isolate shares a high aminoacid identity with the previously reported sequence of the virus, and identities between 80% and 90% with previously reported GLRaV-9 and GLRaV-4 isolates. The analysis of the sequence supports the clustering together with GLRaV-4 and GLRV-9 inside the Ampelovirus genus. 相似文献
74.
Romero C Ventura S Gibaja EL Hervás C Romero F 《Artificial intelligence in medicine》2006,38(1):67-78
OBJECTIVE: We introduce a web-based adaptive training simulator system to exercise cardiopulmonary resuscitation skills. Our purpose is to provide emergency physicians with an additional training tool for cardiac life support clinical cases, by integrating an adaptive learning environment with a web-based case simulator. METHODS AND MATERIALS: Adaptive systems reflect some features of the user in the user model and apply this model to adapt various visible aspects of the system to the user. Our system follows a stage-based learning model with several steps to personalize student learning. First, students learn the theory and content of life support and take computerized tests to evaluate their declarative knowledge of these areas. Second, they practice with clinical case examples and complete an exam at the appropriate level of difficulty to assess their practical knowledge. Finally, they train with additional clinical cases. RESULTS AND CONCLUSION: In order to evaluate the usefulness of the system, we used it in two traditional advanced life support courses at the Jaen Hospital in Spain, as an additional and complementary tool within the course. Results show that the use of adaptation techniques can improve student performance. 相似文献
75.
Barroso S Rieubland C José álvarez A López-Trascasa M Bart PA Núñez-Roldán A Sánchez B 《Immunology》2006,118(2):257-260
Different genetic mutations have been described in complement components resulting in total or subtotal deficiency states. In this work we report the genetic basis of C7 deficiency in a previously reported Spanish patient exhibiting a combined total deficiency of C7 and C4B associated with systemic lupus erythematosus. Exon-specific polymerase chain reaction and sequencing revealed a not previously described single base mutation in exon 10 (T1458A) leading to a stop codon that causes the premature truncation of the C7 protein (C464X). Additionally, a C to A transversion at position 1561 (exon 11) was found in the patient resulting in an amino acid change (R499S). This latter mutation has been previously reported in individuals with subtotal C7 deficiency or with combined subtotal C6/C7 deficiency from widely spaced geographical areas. Another novel mutation was found in a second patient with meningococcal meningitis of Bolivian and Czech origin; a 11-base pair deletion of nucleotides 631-641 in exon 6 leading to the generation of a downstream stop codon causing the premature truncation of the C7 protein product (T189 x 193). This patient was found to be a heterozygous compound for another mutation in C7; a two-base pair deletion of nucleotides 1922 and 1923, 1923 and 1924 or 1924 and 1925 in exon 14 (1922delAG/1923delGA/1924delAG), leading again to the generation of a downstream stop codon that provokes the truncation of the C7 protein (S620x630). This latter mutation has been recently reported by our group in another Spanish family. Our results provide more evidences for the heterogeneous molecular basis of C7 deficiency. 相似文献
76.
77.
78.
Nanocomposites of Microbial Polyglutamic Acid and Nanoclays Compatibilized by Organophosphonium Surfactants 下载免费PDF全文
Ana Gamarra Sebastián Muñoz‐Guerra Lourdes Urpí Elsa Galbis Juan A. Galbis 《Macromolecular chemistry and physics.》2018,219(12)
Ionic coupling of bacterial poly(γ‐glutamic acid) (PGGA) with alkyltrimethylphosphonium surfactants is reported to render comb‐like PGGA complexes with a biphasic‐layered structure displaying periodicity at the nanoscopic scale. In this work, nanocomposites made of PGGA and montmorillonite, and covering a wide variety of compositions, are prepared by using either dodecyl‐ or eicosyl‐trimethylphosphonium surfactant as a third component with a double purpose, that is, ionic complexation of PGGA and organo‐modification of the nanoclay. Thermogravimetric analysis ascertains the compositions of these three‐component nanocomposites and evidences their excellent thermal stability. The nanocomposite structure with PGGA and clay more or less intercalated according to composition and thermal history is evidenced by both X‐ray diffraction and transmission electron microscopy. Simultaneous thermal SAXS/WAXS analysis at real time reveals extensive intermixing of the two phases that become notably enhanced by heating treatment. Thermal transition characteristics of the surfactant–PGGA complex are not significantly altered in the nanocomposites, but elastic moduli and strength to yield are found to increase proportionally to the content of clay. 相似文献
79.
Muñoz San MS Sebastián JL Sancho M Miranda JM 《Physics in medicine and biology》2003,48(11):1649-1659
This paper shows the importance of using realistic cell shapes with the proper geometry and orientation to study the mechanisms of direct cellular effects from radiofrequency (RF) exposure. For this purpose, the electric field distribution within erythrocyte, rod and ellipsoidal cell models is calculated by using a finite element technique with adaptive meshing. The three cell models are exposed to linearly polarized electromagnetic plane waves of frequencies 900 and 2450 MHz. The results show that the amplification of the electric field within the membrane of the erythrocyte shape cell is more significant than that observed in other cell geometries. The results obtained show the dependence of the induced electric field distribution on frequency, electrical properties of membrane and cytoplasm and the orientation of the cell with respect to the applied field. The analysis of the transition of an erythrocyte shape to an ellipsoidal one shows that a uniformly shelled ellipsoid model is a rough approximation if a precise simulation of bioeffects in cells is desired. 相似文献
80.