全文获取类型
收费全文 | 3412篇 |
免费 | 171篇 |
国内免费 | 26篇 |
专业分类
耳鼻咽喉 | 53篇 |
儿科学 | 37篇 |
妇产科学 | 78篇 |
基础医学 | 344篇 |
口腔科学 | 109篇 |
临床医学 | 274篇 |
内科学 | 833篇 |
皮肤病学 | 46篇 |
神经病学 | 347篇 |
特种医学 | 135篇 |
外科学 | 484篇 |
综合类 | 7篇 |
一般理论 | 2篇 |
预防医学 | 144篇 |
眼科学 | 57篇 |
药学 | 236篇 |
中国医学 | 3篇 |
肿瘤学 | 420篇 |
出版年
2023年 | 28篇 |
2022年 | 53篇 |
2021年 | 102篇 |
2020年 | 72篇 |
2019年 | 72篇 |
2018年 | 69篇 |
2017年 | 71篇 |
2016年 | 87篇 |
2015年 | 99篇 |
2014年 | 97篇 |
2013年 | 159篇 |
2012年 | 240篇 |
2011年 | 232篇 |
2010年 | 128篇 |
2009年 | 121篇 |
2008年 | 210篇 |
2007年 | 232篇 |
2006年 | 220篇 |
2005年 | 240篇 |
2004年 | 237篇 |
2003年 | 224篇 |
2002年 | 179篇 |
2001年 | 42篇 |
2000年 | 28篇 |
1999年 | 20篇 |
1998年 | 26篇 |
1997年 | 16篇 |
1996年 | 21篇 |
1995年 | 26篇 |
1994年 | 30篇 |
1993年 | 15篇 |
1992年 | 22篇 |
1991年 | 9篇 |
1990年 | 10篇 |
1989年 | 18篇 |
1988年 | 12篇 |
1987年 | 14篇 |
1986年 | 11篇 |
1985年 | 12篇 |
1984年 | 18篇 |
1983年 | 6篇 |
1982年 | 12篇 |
1981年 | 11篇 |
1980年 | 11篇 |
1978年 | 4篇 |
1975年 | 4篇 |
1974年 | 4篇 |
1937年 | 2篇 |
1910年 | 2篇 |
1899年 | 2篇 |
排序方式: 共有3609条查询结果,搜索用时 15 毫秒
61.
62.
Alfredo Iandolo Dina Abdellatif Massimo Amato Giuseppe Pantaleo Andrea Blasi Vittorio Franco Prasanna Neelakantan 《Australian endodontic journal : the journal of the Australian Society of Endodontology Inc》2020,46(2):204-209
This study investigated the effect of ultrasonic activation of intracanal‐heated sodium hypochlorite (NaOCl) on its dentinal tubular penetration and root canal cleanliness in vitro. In experiment 1, mandibular premolars were randomly allocated to three groups (n = 8): group A, ultrasonic activation; group B, ultrasonic activation of intracanal‐heated NaOCl and group C, syringe‐and‐needle irrigation. Penetration of the fluorescent‐labelled NaOCl was investigated using light microscopy. In experiment 2, mandibular premolars were randomly allocated to group B or C (n = 10), for histological analysis of the remaining pulp tissue and debris. Data were statistically analysed using Kruskal–Wallis and Mann–Whitney tests (P = 0.05). The highest penetration of NaOCl was observed in group B, followed by group A (P < 0.05). Group B showed significantly less amount of debris than group C (P < 0.05). Dentinal tubule penetration of NaOCl and root canal cleanliness were significantly improved by ultrasonic activation of intracanal‐heated NaOCl. 相似文献
63.
Gianluca Coppola Antonio Di Renzo Emanuele Tinelli Barbara Petolicchio Vincenzo Parisi Mariano Serrao Camillo Porcaro Marco Fiorelli Francesca Caramia Jean Schoenen Vittorio Di Piero Francesco Pierelli 《The journal of headache and pain》2021,22(1)
BackgroundWe searched for differences in resting-state functional connectivity (FC) between brain networks and its relationship with the microstructure of the thalamus between migraine with pure visual auras (MA), and migraine with complex neurological auras (MA+), i.e. with the addition of at least one of sensory or language symptom.Methods3T MRI data were obtained from 20 patients with MA and 15 with MA + and compared with those from 19 healthy controls (HCs). We collected resting state data among independent component networks. Diffusivity metrics of bilateral thalami were calculated and correlated with resting state ICs-Z-scores.ResultsAs compared to HCs, both patients with MA and MA + disclosed disrupted FC between the default mode network (DMN) and the right dorsal attention system (DAS). The MA + subgroup had lower microstructural metrics than both HCs and the MA subgroup, which correlated negatively with the strength of DMN connectivity. Although the microstructural metrics of MA patients did not differ from those of HCs, these patients lacked the correlation with the strength of DAS connectivity found in HCs.ConclusionsThe present findings suggest that, as far as MRI profiles are concerned, the two clinical phenotypes of migraine with aura have both common and distinct morpho-functional features of nodes in the thalamo-cortical network. 相似文献
64.
65.
66.
The successful management of a Bronchoesophageal fistula after lung transplantation: a case report 下载免费PDF全文
Stefania Camagni Alessandro Lucianetti Paolo Ravelli Giovanni B. Di Dedda Ezio Bonanomi Vittorio Corno Alessandro Aluffi Domenico Pinelli Marco F. Zambelli Michela Guizzetti Piercarlo Parigi Michele Colledan 《Transplant international》2015,28(7):884-887
We describe an unprecedented, disastrous complication after bilateral lung transplantation (BLT), a bilateral bronchial dehiscence with a right bronchoesophageal fistula leading to life‐threatening septic shock. We also report the successful endoscopic management of this complication by double stenting and stress the efficacy of the multidisciplinary approach to this critical case. 相似文献
67.
Giorgio Minoli M.D. Vittorio Terruzzi M.D. Gianni Imperiali M.D. Guido Frigerio M.D. Enrico Colombo M.D. Umberto Comin M.D. Giuseppe Corsini M.D. Marcello Curzio M.D. Alberto Prada M.D. Francesco Rocca M.D. Renato Venturelli M.D. Andrew Kenneth Burroughs M.D. 《The American journal of gastroenterology》1994,89(1):72-78
Objective : To evaluate if tbere was periodicity in the manifestations of gastrointestinal bleeding (hemateme-sis and melena). Method : This is a multicenter prospective study carried out in the Endoscopy Units of eight hospitals. At the time of the emergency endoscopy, the following data were collected: age, sex, endoscopic diagnosis, solar hour of the first hematemesis (vomiting of bright red or tarry black material) and of the first melena (black or bloody soft stools), and any drugs taken during the week before the bleeding episode, regardless of the dose. Results : 806 patients were studied. Bleeding was from peptic ulcer in 405 patients (50%), from esophageal varices in 197 (24%), and from other sources in the remainder. Analysis using single cosinor statistics showed a nonrandom distribution in bleeding from peptic ulcer, whether presenting first with hematemesis (p = 0.02) or melena (p = 0.03). There were two peaks at 6:45 AM and 6:45 PM for hemate-mesis and at 7:25 AM and 7:25 PM for melena, representing a biphasic diurnal (ultradian) rhythm. Conclusions : This study shows that bleeding due to peptic ulcer has a biphasic diurnal periodicity. 1 his has potential importance for the pathogenesis of bleeding, for the management of gastrointestinal hemorrhage and the administration of drugs known to cause peptic ulcer bleeding. 相似文献
68.
Biological and clinical relevance of matrix metalloproteinases 2 and 9 in acute myeloid leukaemias and myelodysplastic syndromes 总被引:1,自引:0,他引:1
Travaglino E Benatti C Malcovati L Della Porta MG Gallì A Bonetti E Rosti V Cazzola M Invernizzi R 《European journal of haematology》2008,80(3):216-226
We analysed by immunocytochemistry metalloproteinase (MMP)-2 and MMP-9 expression in bone marrow cells from 54 acute myeloid leukaemia (AML) patients, 153 myelodysplastic syndrome (MDS) patients, and 52 non-haemopathic subjects, in order to evaluate whether MMP expression abnormalities were associated with relevant laboratory or clinical findings. In normal samples MMP-2 was detected in rare myeloid cells, MMP-9 in most maturing myeloid cells. In MDS MMP-2 myeloid levels were higher than in controls (P < 0.0001); MMP-2 and MMP-9 were often co-expressed. Also many erythroblasts expressed MMP-2. There was a positive correlation between MMP-2 erythroblast expression and erythroid dysplasia (P = 0.002) and an inverse correlation between MMP-2 or MMP-9 myeloid expression and blast cell percentage (P = 0.05 and P = 0.04 respectively). High MMP levels in myeloid cells were associated with longer overall survival (P = 0.03) and evolution-free survival (P = 0.04). In AML MMP-2 levels were lower than in MDS (P < 0.0001) and MMP-9 levels lower than in MDS and controls (P < 0.0001). MMP levels did not predict response to therapy. The release of active MMPs was detected by colorimetric analysis in cell cultures from representative MDS and AML cases. In conclusion, we have demonstrated an abnormal MMP expression in AML as well as in MDS. The production and release of these enzymes may influence haematopoietic cell behaviour. In MDS, the detection of MMP deregulated expression may be important also from the clinical point of view: it may provide a useful tool for diagnosis, prognosis and a possible target for experimental treatments. 相似文献
69.
Hitomi Hosoya Andrey S. Dobroff Wouter H. P. Driessen Vittorio Cristini Lina M. Brinker Fernanda I. Staquicini Marina Cardó-Vila Sara D’Angelo Fortunato Ferrara Bettina Proneth Yu-Shen Lin Darren R. Dunphy Prashant Dogra Marites P. Melancon R. Jason Stafford Kohei Miyazono Juri G. Gelovani Kazunori Kataoka C. Jeffrey Brinker Richard L. Sidman Wadih Arap Renata Pasqualini 《Proceedings of the National Academy of Sciences of the United States of America》2016,113(7):1877-1882
A major challenge of targeted molecular imaging and drug delivery in cancer is establishing a functional combination of ligand-directed cargo with a triggered release system. Here we develop a hydrogel-based nanotechnology platform that integrates tumor targeting, photon-to-heat conversion, and triggered drug delivery within a single nanostructure to enable multimodal imaging and controlled release of therapeutic cargo. In proof-of-concept experiments, we show a broad range of ligand peptide-based applications with phage particles, heat-sensitive liposomes, or mesoporous silica nanoparticles that self-assemble into a hydrogel for tumor-targeted drug delivery. Because nanoparticles pack densely within the nanocarrier, their surface plasmon resonance shifts to near-infrared, thereby enabling a laser-mediated photothermal mechanism of cargo release. We demonstrate both noninvasive imaging and targeted drug delivery in preclinical mouse models of breast and prostate cancer. Finally, we applied mathematical modeling to predict and confirm tumor targeting and drug delivery. These results are meaningful steps toward the design and initial translation of an enabling nanotechnology platform with potential for broad clinical applications.A long-term goal in contemporary cancer nanomedicine has been to design and generate drug delivery systems that improve the narrow therapeutic window associated with conventional chemotherapeutics (1, 2). Conceptually, several nanotechnology-based entity candidates, including protocells (3), biosynthetic nanoparticles (NPs), viruses, and liposome-based nanoparticles, could be targeted for active delivery through a defined cell surface ligand receptor system and/or physically triggered for finely tuned cargo release (2, 4, 5).Numerous efforts have been made to functionalize NPs by combining them with antibodies, aptamers, peptides, vitamins, or carbohydrates (6–8), but the majority of studies involve untargeted nanoplatforms (4, 9). In practice, targeting NPs is far from trivial, and ongoing challenges include synthesis and purification, selection of an appropriate ligand receptor, and specific composition for NP conjugation. Even the conjugation reaction itself may alter the binding of the tumor-targeting moiety to its receptor through conformational changes, steric freedom restriction, or orientation distortion (10, 11). Unfortunately, the cost-to-benefit ratio of these modifications often elevate the complexity of the NP synthesis, complicating regulatory hurdles because of formulations that are heterogeneous or difficult to reproduce (10, 12, 13).To minimize such drawbacks, NPs can be functionalized via virus-based nanoplatforms as an alternative for targeted cargo delivery (14–16). In particular, filamentous bacteriophage (phage)—a prokaryotic virus—is an attractive candidate to develop a bionanomedicine for cancer therapeutics because phage particles are cost-effectively produced with biological uniformity, as well as being physically robust and stable under harsh conditions (17). Notably, phage-based nanoplatforms are biocompatible and nonpathogenic with eukaryotic organisms and are able to preserve the desired cell targeting and internalization (18). Moreover, phage particles are ideal for incorporating other NPs, which can be released after reaching the tumor site. An admixture of colloidal gold NP (AuNP) with phage particles spontaneously organizes into hydrogel network-like fractal structures (19, 20). These hydrogel networks offer convenient multifunctional integration within a single entity for tumor targeting, enhanced fluorescence and dark-field microscopy, near-infrared (NIR) photon-to-heat conversion, and surface-enhanced Raman scattering (SERS)-based detection (20, 21).In the present work, we developed a tumor targeting theranostic (meaning a combination of therapeutics and diagnostics) hydrogel-based nanoplatform that enables ligand-directed tumor targeting, multimodal imaging capability, and triggered therapeutic cargo release. Our data suggest that targeted hydrogel photothermal therapy represents a functional theranostic approach (fostering “see and treat, treat and see”) in the diagnosis and management of tumors. 相似文献
70.