全文获取类型
收费全文 | 58383篇 |
免费 | 3134篇 |
国内免费 | 554篇 |
专业分类
耳鼻咽喉 | 811篇 |
儿科学 | 1913篇 |
妇产科学 | 998篇 |
基础医学 | 7350篇 |
口腔科学 | 1714篇 |
临床医学 | 4337篇 |
内科学 | 13814篇 |
皮肤病学 | 1690篇 |
神经病学 | 4630篇 |
特种医学 | 1502篇 |
外国民族医学 | 2篇 |
外科学 | 7970篇 |
综合类 | 1349篇 |
一般理论 | 21篇 |
预防医学 | 4774篇 |
眼科学 | 1568篇 |
药学 | 3781篇 |
6篇 | |
中国医学 | 546篇 |
肿瘤学 | 3295篇 |
出版年
2024年 | 70篇 |
2023年 | 475篇 |
2022年 | 740篇 |
2021年 | 1809篇 |
2020年 | 983篇 |
2019年 | 1732篇 |
2018年 | 2427篇 |
2017年 | 1530篇 |
2016年 | 1374篇 |
2015年 | 1431篇 |
2014年 | 1861篇 |
2013年 | 2669篇 |
2012年 | 4438篇 |
2011年 | 4805篇 |
2010年 | 2482篇 |
2009年 | 1743篇 |
2008年 | 3715篇 |
2007年 | 3742篇 |
2006年 | 3384篇 |
2005年 | 3444篇 |
2004年 | 3100篇 |
2003年 | 2925篇 |
2002年 | 2666篇 |
2001年 | 1680篇 |
2000年 | 2034篇 |
1999年 | 1234篇 |
1998年 | 435篇 |
1997年 | 292篇 |
1996年 | 283篇 |
1995年 | 257篇 |
1994年 | 178篇 |
1993年 | 178篇 |
1992年 | 232篇 |
1991年 | 192篇 |
1990年 | 160篇 |
1989年 | 161篇 |
1988年 | 146篇 |
1987年 | 129篇 |
1986年 | 120篇 |
1985年 | 109篇 |
1984年 | 96篇 |
1983年 | 67篇 |
1982年 | 53篇 |
1981年 | 49篇 |
1980年 | 55篇 |
1979年 | 38篇 |
1978年 | 34篇 |
1977年 | 37篇 |
1976年 | 26篇 |
1975年 | 33篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
Sergi Sastre Francisco Maculé Sandra Lasurt Josep-María Segur Lluis Lozano Montse Nuñez Santiago Suso 《European journal of orthopaedic surgery & traumatology : orthopedie traumatologie》2007,17(4):393-397
Five patients with idiopathic transient osteoporosis were examined. Bone scanning and MRI was helpful in the diagnosis to differentiate of necrosis and all patients recovered completely with conservative and symptomatic treatment. There was no history of trauma in all patients. MRI was realized previously in all cases to confirm the diagnosis and after the resolution of symptomathology. 相似文献
12.
M D Blanco M V Bernardo R L Sastre R Olmo E Mu?iz J M Teijón 《European journal of pharmaceutics and biopharmaceutics》2003,55(2):229-236
Poly(epsilon-caprolactone) microspheres containing bupivacaine were prepared by the spray-drying process. The average size of drug loaded microspheres was less than 3 microm in diameter, and the percentage of entrapment efficiency was 91 +/- 3%. In vitro drug release kinetic in phosphate buffer at 37 degrees C showed a hyperbolic profile, with a burst-effect during the first hour. Subcutaneous injection of bupivacaine-loaded microspheres in the back of rats caused an increase in drug concentration in plasma. Maximum bupivacaine concentration in plasma was 237 +/- 58 ng/ml at 105 h, and drug was detected in plasma for 16 days. The half-life time of the drug was increased by more than 125 times with regard to that of the drug administered in a solution by intraperitoneal injection. After 30 days of injection, a mass formed by microspheres surrounded by a thin fibrous capsule was observed. Small blood vessels and multinucleate foreign body giant cells with macrophagic function around microspheres were detected. After 60 days of injection a subcutaneous mass was also observed, which was formed of more degraded dispersed microspheres in conjunctive tissue, which had a normal structure. Thus, bupivacaine-loaded poly(epsilon-caprolactone) microspheres could be considered as a device to be used in the treatment of severe pain that is not responsive to opioids for example in cancer-related syndromes or in intractable herpetic neuralgia. 相似文献
13.
We propose a new self-organizing neural model that performs principal components analysis. It is also related to the adaptive subspace self-organizing map (ASSOM) network, but its training equations are simpler. Experimental results are reported, which show that the new model has better performance than the ASSOM network. 相似文献
14.
15.
Prospective study of antigenemia,plasma viremia and lymphocytic viremia in HIV-infected hemophiliacs
S. Melón Garcia M. de Oña Navarro C. Rodriguez Pinto M. Fernández Urgellés A. Martinez Gutierrez P. de la Iglesia F. J. Mendez García 《European journal of clinical microbiology & infectious diseases》1995,14(5):400-405
A total of 186 blood samples from 24 HIV-1 seropositive hemophiliac patients, monitored every four months for 29 months, were investigated for the presence of viral antigen in plasma. In addition, peripheral blood mononuclear cells (PBMC) were cultured for HIV-1, using normal PBMC as a target for replication. Antigenemia was detected in 51 % of the patients and from PBMC in 87.5 % of the patients. The incidence of HIV isolation in asymptomatic patients (42.8 %) was similar to that found in symptomatic patients (51.4 %). Patients with opportunistic infections had a higher incidence of lymphocytic viremia (p<0.05). Plasma viremia was closely associated (p<0.05) with low CD4+ counts and infection progression. The persistence of antigenemia was also a marker of a poor clinical course. In treated patients, plasma viremia was the marker that better correlated with the clinical course, and it did not appear during the first nine months of therapy. Zidovudine doses of >500 mg/day significantly lowered the appearance of antigenemia and lymphocytic viremia (p<0.05). 相似文献
16.
María Luz Montesinos Manuel Castellano-Muoz Pablo García-Junco-Clemente Rafael Fernndez-Chacn 《Brain Research Reviews》2005,49(2):416-428
In neurons, a network of endocytic proteins accomplishes highly regulated processes such as synaptic vesicle cycling and the timely internalization of intracellular signaling molecules. In this review, we discuss recent advances on molecular networks created through interactions between proteins bearing the Eps15 homology (EH) domain and partner proteins containing the Asn–Pro–Phe (NPF) motif, which participate in important aspects of neuronal function as the synaptic vesicle cycle, the internalization of nerve growth factor (NGF), the determination of neuronal cell fate, the development of synapses and the trafficking of postsynaptic receptors. We discuss novel functional findings on the role of intersectin and synaptojanin and then we focus on the features of an emerging family of EH domain proteins termed EHDs (EH domain proteins), which are important for endocytic recycling of membrane proteins. 相似文献
17.
S Ponce G Orive R M Hernández A R Gascón J M Canals M T Mu?oz J L Pedraz 《Journal of controlled release》2006,116(1):28-34
Alginates are the most employed biomaterials for cell encapsulation due to their abundance, easy gelling properties and apparent biocompatibility. However, as natural polymers different impurities including endotoxins, proteins and polyphenols can be found in their composition. Several purification protocols as well as different batteries of assays to prove the biocompatibility of the alginates in vitro have been recently developed. However, little is known about how the use of alginates with different purity grade may affect the host immune response after their implantation in vivo. The present paper investigates the long-term functionality and biocompatibility of murine erythropoietin (EPO) secreting C2C12 cells entrapped in microcapsules elaborated with alginates with different properties (purity, composition and viscosity). Results showed that independently of the alginate type employed, the animals presented elevated hematocrit levels until day 130, remaining at values between 70-87%. However, histological analysis of the explanted devices showed higher overgrowth around non-biomedical grade alginate microcapsules which could be directly related with higher impurity content of this type of alginate. Although EPO delivery may be limited by the formation of a fibrotic layer around non-biomedical grade alginate microcapsules, the high EPO secretion of the encapsulated cells together with the pharmacodynamic behaviour and the angiogenic and immune-modulatory properties of EPO result in no direct correlation between the biocompatibility of the alginate and the therapeutic response obtained. 相似文献
18.
José Ramón Cansino Alcaide Luis Martínez-Piñeiro 《Clinical & translational oncology》2006,8(3):148-152
Summary Genes involved in cancer generation are usually tumor suppressors and oncogenes. Progressive genetic alterations in these
genes are involved in the mechanisms of tumorigenesis. In prostate cancer, additionally several chromosomal loci that should
harbor mutated genes have been proposed. Some genes have been found altered in prostate cancer, such as PTEN, TP53, AR, RNASEL
(HPC1), ELAC2 (HPC2), CDKN2A and MSR1 and those can be natural targets for new strategies of treatment. Besides, gene therapy
has been suggested to be suitable for prostate cancer treatment. This approach includesex vivo corrective therapy, suicide, and antisense therapy. 相似文献
19.
Juan Francisco Casanova Rafael Herruzo Jesus Diez 《Infection control and hospital epidemiology》2006,27(7):709-715
OBJECTIVES: To assess the appropriateness of using the indices developed by the Study on the Efficacy of Nosocomial Infection Control (SENIC) and the National Nosocomial Infections Surveillance (NNIS) project to determine risk factors for surgical site infection (SSI) in children and, if not appropriate, to explore the factors related to SSI in children so these factors could be used in a risk index for pediatric patients. DESIGN: Cohort study during more than 4 years. SETTING: La Paz University Hospital, a national reference center that serves Health Area 5 of Madrid, Spain, which has approximately 500,000 inhabitants. PATIENTS: Convenience sample consisting of the 3,646 children admitted for surgery who had a postsurgical stay of more than 2 days. RESULTS: A model with 8 predictive factors (degree of surgical contamination; duration of surgery; type of surgery; use of a peripheral venous catheter, central venous catheter, or urinary catheter; number of diagnoses; and SSI exposition time) was created. Its relation to the SSI rate was better than that of the SENIC or NNIS indices. Its sensitivity, specificity, and area under the receiver-operating characteristic curve were higher than that of the SENIC index. CONCLUSIONS: The model that we created seems to be more adequate for predicting SSI and evaluating pediatric patients' intrinsic risk than the SENIC and NNIS indices. 相似文献
20.
Linda Wang D.D.S. M.S. Ph.D. Lawrence Gonzaga Lopes D.D.S. M.S. Ph.D. Eduardo Bresciani D.D.S. M.S. José Roberto Pereira Lauris D.D.S. M.S. Ph.D. Rafael Francisco Lia Mondelli D.D.S. M.S. Ph.D. Maria Fidela de Lima Navarro D.D.S. Ph.D. 《Special care in dentistry》2004,24(1):28-33
Atraumetic Restorative Treatment (ART) has been adopted around the world to avoid unnecessary extractions, especially in non-industrialized countries The development of specific glass ionomer cements marketed for the ART technique has contributed to the technical success rate. In this study. Ketac-Molara (3M ESPE. Dental Medzn Germany) was used to restore 150 Class I cavities in 118 Brazilian public school children, aged from 7–12 years. At baseline and at subsequent recalls. CPI probes with a ball-end of 0.5 millimeters (mm) were used to assess loss of restorative material, and photographic color transparencies of restorations were made. After six months. 83 patients returned for follow-up examinations, with 71.8% of their restorations designated as acceptable. After three years. 49 patients with 57 ART-restorations were evaluated, with 21.0% of these restorations graded as acceptable Another 29.8% of their restorations had been replaced by more permanent materials. The main objective of the ART technique is tooth retention; this was achieved for 94.7% of the restored teeth in a high caries risk population who returned for recalls. 相似文献