全文获取类型
收费全文 | 2285篇 |
免费 | 65篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 19篇 |
儿科学 | 38篇 |
妇产科学 | 21篇 |
基础医学 | 344篇 |
口腔科学 | 14篇 |
临床医学 | 145篇 |
内科学 | 661篇 |
皮肤病学 | 88篇 |
神经病学 | 186篇 |
特种医学 | 87篇 |
外科学 | 395篇 |
综合类 | 17篇 |
一般理论 | 3篇 |
预防医学 | 127篇 |
眼科学 | 27篇 |
药学 | 94篇 |
肿瘤学 | 86篇 |
出版年
2023年 | 10篇 |
2022年 | 16篇 |
2021年 | 40篇 |
2020年 | 32篇 |
2019年 | 30篇 |
2018年 | 42篇 |
2017年 | 29篇 |
2016年 | 37篇 |
2015年 | 29篇 |
2014年 | 58篇 |
2013年 | 79篇 |
2012年 | 114篇 |
2011年 | 151篇 |
2010年 | 73篇 |
2009年 | 81篇 |
2008年 | 127篇 |
2007年 | 173篇 |
2006年 | 150篇 |
2005年 | 145篇 |
2004年 | 115篇 |
2003年 | 79篇 |
2002年 | 94篇 |
2001年 | 20篇 |
2000年 | 20篇 |
1999年 | 23篇 |
1998年 | 24篇 |
1997年 | 10篇 |
1996年 | 16篇 |
1995年 | 19篇 |
1994年 | 23篇 |
1993年 | 12篇 |
1989年 | 10篇 |
1978年 | 9篇 |
1960年 | 10篇 |
1958年 | 9篇 |
1943年 | 9篇 |
1939年 | 8篇 |
1936年 | 10篇 |
1935年 | 8篇 |
1933年 | 13篇 |
1932年 | 12篇 |
1931年 | 11篇 |
1930年 | 9篇 |
1929年 | 10篇 |
1928年 | 9篇 |
1927年 | 15篇 |
1926年 | 13篇 |
1925年 | 15篇 |
1924年 | 14篇 |
1911年 | 11篇 |
排序方式: 共有2352条查询结果,搜索用时 12 毫秒
31.
Benedikt Bosbach Shayu Deshpande Ferdinand Rossi Jae-Hung Shieh Gunhild Sommer Elisa de Stanchina Darren R. Veach Joseph M. Scandura Katia Manova-Todorova Malcolm A. S. Moore Cristina R. Antonescu Peter Besmer 《Proceedings of the National Academy of Sciences of the United States of America》2012,109(34):E2276
32.
Ferdinand von Meyenn Martin Schaefer Heike Weighardt Stefan Bauer Carsten J. Kirschning Hermann Wagner Tim Sparwasser 《Immunobiology》2006,211(6-8):557
Recognition of mycobacteria by the innate immune system is essential for the development of an adaptive immune response. Mycobacterial antigens stimulate antigen presenting cells (APCs) through distinct Toll-like receptors (TLRs) resulting in rapid activation of the innate immune system. The role of TLRs during infection with Mycobacterium bovis Bacillus Calmette-Guérin (BCG) has been evaluated for TLR2 and TLR4 only. Surprisingly, despite the fact that immune stimulatory CpG-motifs have been originally derived from BCG, for the vaccine strain the role of TLR9 has not been addressed before. To identify the set of TLRs involved in the recognition of BCG, we infected bone marrow-derived macrophages and bone marrow-derived dendritic cells (Flt3-ligand generated DCs) from TLR2, TLR3, TLR4, TLR7, TLR9, MyD88 knockout, TLR2/4 and TLR2/4/9 multiple knockout mice. The degree of activation and stimulation was determined by TNFα, IL-6 and IL-12p40 ELISA. Activation of DCs was measured by surface expression of the costimulatory molecule CD86. We observed the most dramatic reduction of the inflammatory response for TLR2-deficient antigen presenting cells. Both macrophages and DCs produce markedly decreased amounts of TNFα and IL-6 in the absence of TLR2 whereas no significant reduction could be observed for TLR3, 4, 7, 9 single TLR-knockouts. However, IL-12 production in DCs appears not exclusively dependent on TLR2 and only in TLR2/4/9-deficient DCs BCG-induced IL-12 is reduced to background levels. Similarly, up-regulation of CD86 is abolished only in TLR2/4/9-deficient DCs supporting a role of TLR9 in the recognition of M. bovis BCG by murine dendritic cells. 相似文献
33.
Ofili EO Ferdinand KC Saunders E Neutel JM Bakris GL Cushman WC Sowers JR Weber MA 《Journal of the National Medical Association》2006,98(4):618-626
The IrbesartaN/hydroChlorothiazide (HCTZ) bLood pressUre reductionS In diVErse patient populations (INCLUSIVE) trial was a multicenter, prospective, open-label, single-arm study evaluating the efficacy and safety of irbesartan/HCTZ fixed combinations in patients > or = 18 years old with uncontrolled systolic blood pressure (SBP, 140-159 mmHg; 130-159 mmHg for type-2 diabetes mellitus patients) after > or = 4 weeks of antihypertensive monotherapy. This analysis focused on different racial/ethnic subgroups. Treatment was sequential: placebo (4-5 weeks), HCTZ 12.5 mg (two weeks), irbesartan/HCTZ 150/12.5 mg (eight weeks) and irbesartan/HCTZ 300/25 mg (eight weeks). Overall, 515 Caucasians, 191 African Americans and 119 Hispanics/Latinos completing placebo treatment were enrolled. Mean SBP changes from baseline (placebo treatment end) to week 18 were -21.5 +/- 13.8 mmHg for Caucasians, -20.7 +/- 16.5 mmHg for African Americans and -22.9 +/- 13.2 mmHg for Hispanics/Latinos, respectively (p<0.001 for each). Mean diastolic BP (DBP) changes were statistically significant (p<0.001) and similar among racial/ethnic subgroups. By week 18, 70% (95% CI, 66%, 74%) of Caucasian, 66% (95% CI, 59%, 74%) of African-American and 65% (95% CI, 57%, 74%) of Hispanic/Latino patients achieved dual SBP/DBP goal. Treatments appeared to be well tolerated. In conclusion, irbesartan/HCTZ treatment provided SBP/DBP goal attainment in approximately two-thirds of Caucasian, African-American and Hispanic/Latino patients with SBP uncontrolled on antihypertensive monotherapy. 相似文献
34.
von Meyenn F Schaefer M Weighardt H Bauer S Kirschning CJ Wagner H Sparwasser T 《Immunobiology》2006,211(6-8):557-565
Recognition of mycobacteria by the innate immune system is essential for the development of an adaptive immune response. Mycobacterial antigens stimulate antigen presenting cells (APCs) through distinct Toll-like receptors (TLRs) resulting in rapid activation of the innate immune system. The role of TLRs during infection with Mycobacterium bovis Bacillus Calmette-Guérin (BCG) has been evaluated for TLR2 and TLR4 only. Surprisingly, despite the fact that immune stimulatory CpG-motifs have been originally derived from BCG, for the vaccine strain the role of TLR9 has not been addressed before. To identify the set of TLRs involved in the recognition of BCG, we infected bone marrow-derived macrophages and bone marrow-derived dendritic cells (Flt3-ligand generated DCs) from TLR2, TLR3, TLR4, TLR7, TLR9, MyD88 knockout, TLR2/4 and TLR2/4/9 multiple knockout mice. The degree of activation and stimulation was determined by TNFalpha, IL-6 and IL-12p40 ELISA. Activation of DCs was measured by surface expression of the costimulatory molecule CD86. We observed the most dramatic reduction of the inflammatory response for TLR2-deficient antigen presenting cells. Both macrophages and DCs produce markedly decreased amounts of TNFalpha and IL-6 in the absence of TLR2 whereas no significant reduction could be observed for TLR3, 4, 7, 9 single TLR-knockouts. However, IL-12 production in DCs appears not exclusively dependent on TLR2 and only in TLR2/4/9-deficient DCs BCG-induced IL-12 is reduced to background levels. Similarly, up-regulation of CD86 is abolished only in TLR2/4/9-deficient DCs supporting a role of TLR9 in the recognition of M. bovis BCG by murine dendritic cells. 相似文献
35.
Background
Routines for the storage of whole blood (WB) overnight for the preparation of blood components on the following day are of increasing interest primarily for logistic reasons. The present study focuses on in vitro effects during storage for 6 weeks on red blood cells (RBC) prepared in different blood containers after being held overnight.Study design and methods
Five different blood collection systems were used with either inline leucocyte reduction red cell filters for the preparation of RBC, buffy coat (BC) and plasma or WB filters for the preparation of RBC and plasma. A new container with an integrated WB filter removing leucocytes but not platelets was also included for the preparation of leucocyte-reduced RBC, BC and plasma units. Standard CPD solution (63 or 70 mL) and SAG-M solution (100 or 110 mL) were used for the collection of either 450 or 500 mL blood. All WB units were stored at room temperature, either overnight for 18–24 hours (test groups, n=104) or for up to 8 hours (reference groups, n=20). In addition, five test units were stored overnight under refrigeration.Results
In test groups (overnight storage at room temperature) we found significantly lower levels of extracellular potassium, 2,3-DPG and pH (up to day 28). During storage, higher levels of ATP (Terumo, CaridianBCT until day 35, Fresenius until day 14, Fenwal throughout storage) were seen in test groups than in reference groups. When WB was stored overnight at 2–6°C before WB filtration, the levels of ATP and haemolysis were higher than in the corresponding reference.Conclusion
Significant differences in in vitro parameters were observed between RBC prepared within 8 hours and 18–24 hours after blood collection. The results were consistent irrespective of the blood container used. New alkaline solutions may decrease the differences. 相似文献36.
Quantitative susceptibility mapping (QSM) based on gradient echo (GRE) magnetic resonance phase data is a novel technique for non-invasive assessment of magnetic tissue susceptibility differences. The method is expected to be an important means to determine iron distributions in vivo and may, thus, be instrumental for elucidating the physiological role of iron and disease-related iron concentration changes associated with various neurological and psychiatric disorders. This study introduces a framework for QSM and demonstrates calculation of reproducible and orientation-independent susceptibility maps from GRE data acquired at 3T. The potential of these susceptibility maps to perform anatomical imaging is investigated, as well as the ability to measure the venous blood oxygen saturation level in large vessels, and to assess the local tissue iron concentration. In order to take into account diamagnetic susceptibility contributions induced by myelin, a correction scheme for susceptibility based iron estimation is demonstrated. The findings suggest that susceptibility contrast, and therewith also phase contrast, are not only linked to the storage iron concentration but are also significantly influenced by other sources such as myelin. After myelin correction the linear dependence between magnetic susceptibilities and previously published iron concentrations from post mortem studies was significantly improved. Finally, a comparison between susceptibility maps and processed phase images indicated that caution should be exercised when drawing conclusions about iron concentrations when directly assessing processed phase information. 相似文献
37.
Ferdinand LG Kelly UA Skelton K Stephens KJ Bradley B 《Issues in mental health nursing》2011,32(9):552-559
Military sexual trauma (MST) increases the risk for Posttraumatic Stress Disorder (PTSD) and multiple other comorbidities, presenting substantial challenges for nurses and psychiatric and medical clinicians. A specialized VA Medical Center outpatient program is patterned after Herman's three-phased, empirically-supported, recovery treatments. We use a case example of a female veteran MST survivor to illustrate our treatment model. She presented to our program meeting diagnostic criteria for PTSD, Major Depressive Disorder, and a history of substance abuse. Post-treatment she demonstrated improved scores on measures of PTSD, quality of life, and socialization. This model shows promise for treatment of MST survivors with PTSD. 相似文献
38.
39.
Willinger B Kopetzky G Harm F Apfalter P Makristathis A Berer A Bankier A Winkler S 《Journal of clinical microbiology》2004,42(1):478-480
Disseminated infection with the coelomycetous fungus Nattrassia mangiferae is a very rare disease affecting only the immunocompromised host. We report the first case of a disseminated infection with spondylodiscitis and granular skin lesions due to N. mangiferae in a renal transplant patient. 相似文献
40.
Handedness remains an enigmatic phenomenon. There is no definitive explanation as to why man should have single rather than dual handedness. Intuitively it would seem advantageous in almost every context to have the benefit of equally dextrous hands. Either in context of warfare or hunting, using two hands equally as effectively would appear to be a favourable adaptation over single dexterity. No satisfactory explanation has been offered as to why and how single-handedness evolved. 相似文献