全文获取类型
收费全文 | 8356篇 |
免费 | 569篇 |
国内免费 | 81篇 |
学科分类
医药卫生 | 9006篇 |
出版年
2024年 | 16篇 |
2023年 | 136篇 |
2022年 | 272篇 |
2021年 | 394篇 |
2020年 | 256篇 |
2019年 | 327篇 |
2018年 | 328篇 |
2017年 | 273篇 |
2016年 | 307篇 |
2015年 | 378篇 |
2014年 | 426篇 |
2013年 | 535篇 |
2012年 | 799篇 |
2011年 | 792篇 |
2010年 | 415篇 |
2009年 | 323篇 |
2008年 | 464篇 |
2007年 | 446篇 |
2006年 | 417篇 |
2005年 | 341篇 |
2004年 | 275篇 |
2003年 | 250篇 |
2002年 | 182篇 |
2001年 | 70篇 |
2000年 | 66篇 |
1999年 | 56篇 |
1998年 | 45篇 |
1997年 | 19篇 |
1996年 | 22篇 |
1995年 | 22篇 |
1994年 | 9篇 |
1993年 | 13篇 |
1992年 | 38篇 |
1991年 | 20篇 |
1990年 | 27篇 |
1989年 | 34篇 |
1988年 | 26篇 |
1987年 | 21篇 |
1986年 | 29篇 |
1985年 | 18篇 |
1984年 | 17篇 |
1983年 | 11篇 |
1979年 | 12篇 |
1978年 | 6篇 |
1977年 | 8篇 |
1976年 | 8篇 |
1975年 | 11篇 |
1973年 | 6篇 |
1972年 | 8篇 |
1969年 | 5篇 |
排序方式: 共有9006条查询结果,搜索用时 15 毫秒
91.
92.
A Randomized Comparison of Alternative Techniques to Achieve Coronary Sinus Cannulation During Biventricular Implantation Procedures 总被引:1,自引:0,他引:1
Giuseppe De Martino Tommaso Sanna Antonio Dello Russo Gemma Pelargonio Loredana Messano Carolina Ierardi Daniele Gabrielli Quintino Parisi Paolo Zecchi Fulvio Bellocci Filippo Crea 《Journal of interventional cardiac electrophysiology》2004,10(3):227-230
INTRODUCTION: Biventricular pacing system implantation is a time-consuming and challenging procedure. A critical step in biventricular pacemaker implantation is coronary sinus (CS) cannulation. CS cannulation can be achieved either using dedicated guiding catheters (guiding catheter alone positioning strategy, GCA) or with the aid of an electrophysiology catheter advanced inside the guiding catheter (electrophysiology catheter aided positioning strategy, EPA). AIM OF THE STUDY: To evaluate whether the EPA technique is useful for reducing CS cannulation time compared to a conventional GCA technique. METHODS: Thirty-four consecutive patients were randomly assigned to the GCA (18 patients) or EPA (16 patients) CS cannulation strategy. RESULTS: Time to successful catheterization of CS was 5.0 +/- 2.4 min in the EPA group versus 10.1 +/- 5.4 min in the GCA group p = 0.004. Fluoroscopy time was 4.6 +/- 2.3 min in the EPA group versus 9.2 +/- 4.9 min in the GCA group p = 0.004. Total contrast dye volume to search and engage the CS ostium was 0.0 ml in the EPA group versus 14.3 +/- 3.4 ml in the GCA group p < 0.001. CONCLUSIONS: Cannulation of CS with the adjunct of an electrophysiology catheter to dedicated delivery systems significantly reduces procedural time, fluoroscopy time and contrast dye volume compared to a conventional strategy. 相似文献
93.
94.
Luna Gargani Cosimo Bruni Tatiana Barskova Valentina Hartwig Martina Marinelli Maria Giovanna Trivella Marco Matucci-Cerinic Antonio LAbbate 《Seminars in arthritis and rheumatism》2019,48(5):867-873
Objectives
Systemic sclerosis (SSc) causes functional and structural microcirculatory dysfunction, affecting also distal extremities. Optical Near-InfraRed Spectroscopy (NIRS) of blood HbO2 saturation (stO2) is able to evaluate O2 delivery/consumption balance in the explored tissue. The NIRS-sensitive camera non-invasively detects stO2 values in superficial tissues, automatically generating 2D-imaging maps in real time. We aimed at testing whether NIRS hand imaging may evaluate peripheral microcirculatory dysfunction and its spatial heterogeneity in SSc patients compared to controls.Methods
Forty SSc patients (aged 55.1?±?15.6 years) and twenty-one healthy controls (aged 54.3?±?14.5years, p?=?0.89) were studied by palmar hand NIRS-2D imaging. A blood pressure cuff was applied to the forearm and 3 min ischemia was induced. Images were acquired at basal conditions and every 10 seconds during 3 minutes of ischemia and 5 minutes of reperfusion. Five regions of interest were positioned on each fingertip, from the second to the fifth finger and one on the thenar eminence.Results
A significant difference was found between controls and SSc patients in basal stO2 (84.3?±?7.5?vs. 75.4?±?10.9%, p?<?0.001), minimum stO2 (65.2?±?8.0?vs. 53.4?±?10.1%, p?<?0.001) and time to maximum stO2 during hyperemia (63?±?38?vs. 85?±?49?s, p?<?0.05). Among clinical characteristics, anti-Scl70 antibody positivity, digital ulcers history and smoke exposure affected NIRS parameters, as well as sildenafil and statins therapy. Conversely, no significant differences were found in NIRS-2D values between different nailfold-videocapillaroscopy patterns.Conclusion
NIRS-2D imaging is a simple, automated tool to non-invasively detect regional microcirculatory impairment in SSc, which seems to add significant functional information to the morphological picture of nailfold-videocapillaroscopy. 相似文献95.
96.
Di Benedetto G Zoccarato A Lissandron V Terrin A Li X Houslay MD Baillie GS Zaccolo M 《Circulation research》2008,103(8):836-844
Protein kinase A (PKA) is a key regulatory enzyme that, on activation by cAMP, modulates a wide variety of cellular functions. PKA isoforms type I and type II possess different structural features and biochemical characteristics, resulting in nonredundant function. However, how different PKA isoforms expressed in the same cell manage to perform distinct functions on activation by the same soluble intracellular messenger, cAMP, remains to be established. Here, we provide a mechanism for the different function of PKA isoforms subsets in cardiac myocytes and demonstrate that PKA-RI and PKA-RII, by binding to AKAPs (A kinase anchoring proteins), are tethered to different subcellular locales, thus defining distinct intracellular signaling compartments. Within such compartments, PKA-RI and PKA-RII respond to distinct, spatially restricted cAMP signals generated in response to specific G protein-coupled receptor agonists and regulated by unique subsets of the cAMP degrading phosphodiesterases. The selective activation of individual PKA isoforms thus leads to phosphorylation of unique subsets of downstream targets. 相似文献
97.
Sonia Gutiérrez Silvia Guillemi Natalie Jahnke Valentina Montessori P Richard Harrigan Julio S G Montaner 《Clinical infectious diseases》2008,46(3):e28-e30
We summarize the clinical history and laboratory results following the introduction of tenofovir among 6 patients coinfected with human immunodeficiency virus (HIV) and hepatitis B virus (HBV) who presented with severe liver disease while receiving lamivudine-based highly active antiretroviral therapy. In all cases, the introduction of tenofovir led to a sustained undetectable HBV and HIV loads, with marked clinical and laboratory improvement in liver function. We provide supporting evidence for the role of tenofovir in the management of advanced HBV infection in HIV-positive patients after the development of lamivudine resistance. 相似文献
98.
Lack of Hypophagia in CB1 Null Mice is Associated to Decreased Hypothalamic POMC and CART Expression
Ricardo Lage Claudia Parisi Patricia Seoane-Collazo Johan Fern? Roberta Mazza Fátima Bosch Luisa M. Seoane Ruben Nogueiras Carlos Diéguez Carmelo Quarta Miguel López 《The international journal of neuropsychopharmacology / official scientific journal of the Collegium Internationale Neuropsychopharmacologicum (CINP)》2015,18(9)
99.
Silvia Angela Debonis Alberto Bongiovanni Federica Pieri Valentina Fausti Alessandro De Vita Nada Riva Lorena Gurrieri Silvia Vanni Danila Diano Laura Mercatali Toni Ibrahim 《Medicine》2021,100(20)
Rationale:Inflammatory myofibroblastic tumor (IMT) is a rare mesenchymal tumor that is prevalent among children and adolescents. Surgery is the most important therapeutic approach for IMT and complete resection is recommended. Although 50% of IMTs show anaplastic lymphoma kinase (ALK) rearrangements, crizotinib has proven an effective therapeutic approach. However, the genetic landscape of this tumor is still not fully understood and treatment options are limited, especially in the majority of ALK-negative tumors.Patient concerns:We describe the clinical case of a healthy 18-year-old female in whom a pulmonary nodule was incidentally detectedDiagnoses:Following a small increase in the size of the nodule, the patient underwent both 18FDG-PET/CT and 68Ga-PET/CT, resulting in a suspicion of bronchial hamartoma.Interventions:The patient underwent surgery and a salivary gland-like lung tumor was diagnosed.Outcomes:After surgery, the patient was referred to our cancer center, where a review of the histology slides gave a final diagnosis of ALK-negative lung IMT. Given the histology, it was decided not to administer adjuvant therapy and the patient was placed in a 3-monthly follow-up program. The patient is still disease-free 2 years post-surgery.Lessons:Although there is no standard of care for the treatment of IMT, identifying genomic alterations could help to redefine the management of patients with negative-ALK disease. Our review of the literature on IMT and other kinase fusions revealed, in addition to ALK rearrangements, the potential association of ROS1, NTRK, RET, or PDGFR beta alterations with the tumor. 相似文献