全文获取类型
收费全文 | 9470篇 |
免费 | 428篇 |
国内免费 | 74篇 |
专业分类
耳鼻咽喉 | 74篇 |
儿科学 | 231篇 |
妇产科学 | 197篇 |
基础医学 | 1207篇 |
口腔科学 | 377篇 |
临床医学 | 584篇 |
内科学 | 2101篇 |
皮肤病学 | 230篇 |
神经病学 | 834篇 |
特种医学 | 197篇 |
外科学 | 1265篇 |
综合类 | 35篇 |
一般理论 | 3篇 |
预防医学 | 909篇 |
眼科学 | 307篇 |
药学 | 525篇 |
中国医学 | 35篇 |
肿瘤学 | 861篇 |
出版年
2023年 | 60篇 |
2022年 | 165篇 |
2021年 | 328篇 |
2020年 | 176篇 |
2019年 | 257篇 |
2018年 | 266篇 |
2017年 | 179篇 |
2016年 | 217篇 |
2015年 | 272篇 |
2014年 | 366篇 |
2013年 | 474篇 |
2012年 | 740篇 |
2011年 | 773篇 |
2010年 | 385篇 |
2009年 | 399篇 |
2008年 | 688篇 |
2007年 | 650篇 |
2006年 | 611篇 |
2005年 | 593篇 |
2004年 | 534篇 |
2003年 | 416篇 |
2002年 | 432篇 |
2001年 | 89篇 |
2000年 | 72篇 |
1999年 | 58篇 |
1998年 | 72篇 |
1997年 | 58篇 |
1996年 | 63篇 |
1995年 | 48篇 |
1994年 | 35篇 |
1993年 | 30篇 |
1992年 | 37篇 |
1991年 | 34篇 |
1990年 | 32篇 |
1989年 | 39篇 |
1988年 | 26篇 |
1987年 | 27篇 |
1986年 | 24篇 |
1985年 | 36篇 |
1984年 | 27篇 |
1983年 | 22篇 |
1982年 | 16篇 |
1981年 | 13篇 |
1979年 | 14篇 |
1978年 | 7篇 |
1977年 | 11篇 |
1975年 | 6篇 |
1974年 | 8篇 |
1972年 | 6篇 |
1971年 | 8篇 |
排序方式: 共有9972条查询结果,搜索用时 15 毫秒
11.
Manohar Bance Alfredo Campos Lillian Wong David P Morris Rene van Wijhe 《Otolaryngology--head and neck surgery》2007,137(1):70-73
OBJECTIVES: The transmission of vibrations from the tympanic membrane to the stapes footplate by an ossicular reconstruction prosthesis is affected by the size of the prosthesis head. We sought to determine if augmenting or reducing the head size of prosthesis had a systematic effect on transmission of vibrations to the stapes. STUDY DESIGN: We conducted a fresh cadaveric temporal bone middle ear study. METHODS: The incus was replaced with a prosthesis using a tympanic membrane to stapes head (TASH)-type hydroxyapatite prosthesis in nine fresh cadaveric temporal bones. Three prosthesis head sizes were created: unaltered, reduced, and augmented. Stapes vibrations were measured with a laser Doppler vibrometer in response to acoustic frequency chirps at 90 dB SPL. RESULTS: All three head size prostheses resulted in smaller stapes vibrations than the intact ear. There was no difference in the vibration transmission between the three different head sizes. All prostheses showed a vibration loss of 10 to 15 dB compared to the intact ear. CONCLUSIONS AND SIGNIFICANCE: Within the range of sizes tested, prosthesis head size had little impact on vibration transmission to the stapes footplate. 相似文献
12.
Neuropsychologic symptoms in the migraine syndrome 总被引:1,自引:0,他引:1
Twenty patients with complex neuropsychologic symptoms associated with classic migraine were selected from a group of 200 patients with vascular headache. Twenty types of symptoms were found and grouped into six categories (language, visual symptoms, cognitive-dysmnesic symptoms, olfactory-gustatory hallucinations, automatisms, and somatosensory symptoms). Some of the symptoms found have apparently not been reported previously. The importance of the analysis of this complex neuropsychologic set of symptoms and of the possible consequences of complicated, frequent vascular headache is emphasized. 相似文献
13.
Alfredo Avellaneda Fernández álvaro Pérez Martín Maravillas Izquierdo Martínez Mar Arruti Bustillo Francisco Javier Barbado Hernández Javier de la Cruz Labrado Rafael Díaz-Delgado Pe?as Eduardo Gutiérrez Rivas Cecilia Palacín Delgado José Ramón Ramón Giménez Javier Rivera Redondo 《Atencion primaria / Sociedad Espa?ola de Medicina de Familia y Comunitaria》2009,41(10):e1-e5
14.
Antonio Bobbio Alfredo Chetta Luca Ampollini Gian Luca Primomo Eveline Internullo Paolo Carbognani Michele Rusca Dario Olivieri 《European journal of cardio-thoracic surgery》2008,33(1):95-98
BACKGROUND: The impact of short-term preoperative pulmonary rehabilitation on exercise capacity of patients with chronic obstructive pulmonary disease undergoing lobectomy for non-small cell lung cancer is evaluated. METHODS: A prospective observational study was designed. Inclusion criteria consisted of an indication to lung resection because of a clinical stage I or II non-small cell lung cancer and a chronic obstructive disease on preoperative pulmonary function test. In such conditions, maximal oxygen consumption by a cardio-pulmonary exercise test was evaluated; when this resulted as being < or =15 ml/kg/min a pulmonary rehabilitation programme lasting 4 weeks was considered. Twelve patients fulfilled inclusion criteria, completed the preoperative rehabilitation programme and underwent a new functional evaluation prior to surgery. The postoperative record of these patients was collected. RESULTS: On completion of pulmonary rehabilitation, the resting pulmonary function test and diffuse lung capacity of patients was unchanged, whereas the exercise performance was found to have significantly improved; the mean increase in maximal oxygen consumption proved to be at 2.8 ml/kg/min (p<0.01). Eleven patients underwent lobectomy; no postoperative mortality was noted and mean hospital stay was 17 days. Postoperative pulmonary complication was recorded in 8 patients. CONCLUSIONS: Short-term preoperative pulmonary rehabilitation could improve the exercise capacity of patients with chronic obstructive pulmonary disease who are candidates for lung resection for non-small cell lung cancer. 相似文献
15.
J. Román Corona-Rivera Alfredo Corona-Rivera Sylvia E. Totsuka-Sutto Enrique Corona-Rivera 《Clinical genetics》1997,51(4):257-259
Gluteal and lower extremity hypoplasia with ipsilateral toe brachysyndactyly were noted in a 23-year-old woman similarly affected to the only previously reported case of the lower extremity counterpart of Poland sequence. Since no neurological deficit was found, and electromyographic and nerve conduction studies in the affected limb were normal, we propose a vascular origin which would involve the external iliac artery supply analogous to the subclavian artery supply disruption in the upper extremity Poland sequence. 相似文献
16.
The weights of 21 patients with Alzheimer's Disease were studied longitudinally for 1.0-8.1 years. 71% lost weight. The rate of weight loss was significantly greater than in normal females aged 60-69 and 70 and over. 相似文献
17.
The goal of IMRT is to achieve an isodose distribution conformed to the tumor while avoiding the organs at risk. For these tasks several gantry angles are selected, each one containing a series of different leaf configurations for the multileaf collimator (MLC) (segments). Verifying the relative distributions as well as the absolute doses is an important step for quality assurance issues. We have observed that an accurate modeling of the transmission of the primary x-ray fluence through the jaws and MLC as well as the head scatter is crucial for a precise calculation of relative doses and monitor units. Also, an inaccurate calculation of the output factor for small size segments can lead to important differences in the absolute dose for points under these segments. Incorrect models could lead to systematic errors of around 5% to 10% in the calculated monitor units and a shift in the isodose curves. 相似文献
18.
Tavares E Maldonado R Ojeda ML Miñano FJ 《Clinical and diagnostic laboratory immunology》2005,12(9):1085-1093
Gram-negative and gram-positive infections have been considered the most important causes of morbidity and mortality in patients with leukopenia following chemotherapy. However, discrimination between bacterial infections and harmless fever episodes is difficult. Because classical inflammatory signs of infection are often absent and fever is frequently the only sign of infection, the aim of this study was to assess the significance of serum interleukin-6 (IL-6), IL-10, macrophage inflammatory protein-2 (MIP-2), procalcitonin (PCT), and C-reactive protein (CRP) patterns in identifying bacterial infections during start of fever in normal and cyclophosphamide-treated (leukopenic) rats following an injection of lipopolysaccharide (LPS) or muramyl dipeptide (MDP) as a model for gram-negative and gram-positive bacterial infections. We found that, compared to normal rats, immunosuppressed animals exhibited significantly higher fevers and lesser production of all mediators, except IL-6, after toxin challenge. Moreover, compared to rats that received MDP, both groups of animals that received an equivalent dose of LPS showed significantly higher fevers and greater increase in serum cytokine levels. Furthermore, in contrast to those in immunocompetent rats, serum levels of IL-6 and MIP-2 were not significantly changed in leukopenic animals after MDP injection. Other serum markers such as PCT and CRP failed to discriminate between bacterial stimuli in both groups of animals. These results suggest that the use of the analyzed serum markers at an early stage of fever could give useful information for the clinician for excluding gram-negative from gram-positive infections. 相似文献
19.
Severe, late-onset graft-versus-host disease in a liver transplant recipient documented by chimerism analysis 总被引:4,自引:0,他引:4
Pollack MS Speeg KV Callander NS Freytes CO Espinoza AA Esterl RM Abrahamian GA Washburn WK Halff GA 《Human immunology》2005,66(1):28-31
A 52-year-old liver transplant recipient presented 8 months after transplantation with oral thrush, then 3 days later with oral ulcers and a diffuse rash, and 5 days later with an acutely reduced white blood cell count, rash, fever, and diarrhea. Bone marrow biopsy revealed severe aplasia. Although graft-versus-host disease (GVHD) was considered, the late onset of these symptoms was felt to render this etiology unlikely because GVHD usually occurs 2 to 6 weeks after transplantation. All potentially myelosuppressive medications were discontinued, and the patient was treated with high doses of hematopoietic growth factors. Because his symptoms continued, chimerism analysis was performed, which indicated that 96% of the peripheral blood mononuclear cells were of liver-donor origin. Ultimately, the patient underwent an allogeneic peripheral blood hematopoietic progenitor cell transplant from a human leukocyte antigen-identical brother, but he died 5 days after transplantation of overwhelming Candida kruseii infection. To our knowledge, this is the first chimerism-analysis-documented case of severe acute GVHD presenting so late after liver transplantation. It is of note that the patient had no known risks for GVHD in that he was relatively young and shared only one major human leukocyte antigen with his donor. Consideration should be given to GVHD as a cause of bone marrow aplasia at any time after organ transplantation. Storage of cell pellets from all transplant recipients and donors is highly recommended to facilitate the diagnostic evaluation. 相似文献
20.
Annunziata I Lanzara C Conte I Zullo A Ventruto V Rinaldi MM D'Urso M Casari G Ciccodicola A Miano MG 《American journal of medical genetics. Part A》2003,(3):217-222
X-linked nonspecific mental retardation (MRX) accounts for approximately 25% of mental retardation in males. A number of MRX loci have been mapped on the X chromosome, reflecting the complexity of gene action in central nervous system (CNS) specification and function. Eleven MRX genes have been identified, but many other causative loci remain to be refined to the single gene level. In 21 MRX families, the causative gene is located in the pericentromeric region; and we report here the identification by linkage analysis of a further such locus, MRX81. The new MRX locus was identified by two- and multi-point parametric analysis carried out on a large Italian family. Tight linkage of MRX81 to DNA markers ALAS2, DXS991, and DXS7132 was observed with a maximum LOD score of 3.43. Haplotype construction delineates an MRX81 critical region of 8 cM, the smallest MRX pericentromeric interval so far described, between DXS1039 and DXS1216, and placing it in Xp11.2-Xq12. So far, automated sequencing of two candidates in the region, the MRX gene oligophrenin (OPHN1) and the brain-specific ephrinB1 (EFNB1) gene, in DNA from affected males excluded their candidacy for MRX81, suggesting a novel disease gene. 相似文献