全文获取类型
收费全文 | 51960篇 |
免费 | 2803篇 |
国内免费 | 101篇 |
专业分类
耳鼻咽喉 | 867篇 |
儿科学 | 1962篇 |
妇产科学 | 1053篇 |
基础医学 | 6904篇 |
口腔科学 | 1967篇 |
临床医学 | 3202篇 |
内科学 | 12407篇 |
皮肤病学 | 1798篇 |
神经病学 | 4416篇 |
特种医学 | 1318篇 |
外科学 | 7465篇 |
综合类 | 262篇 |
一般理论 | 18篇 |
预防医学 | 4186篇 |
眼科学 | 1305篇 |
药学 | 2987篇 |
中国医学 | 246篇 |
肿瘤学 | 2501篇 |
出版年
2024年 | 44篇 |
2023年 | 378篇 |
2022年 | 488篇 |
2021年 | 1459篇 |
2020年 | 782篇 |
2019年 | 1496篇 |
2018年 | 2282篇 |
2017年 | 1363篇 |
2016年 | 1205篇 |
2015年 | 1150篇 |
2014年 | 1457篇 |
2013年 | 2275篇 |
2012年 | 3918篇 |
2011年 | 4406篇 |
2010年 | 2206篇 |
2009年 | 1436篇 |
2008年 | 3538篇 |
2007年 | 3571篇 |
2006年 | 3301篇 |
2005年 | 3344篇 |
2004年 | 2944篇 |
2003年 | 2795篇 |
2002年 | 2519篇 |
2001年 | 1428篇 |
2000年 | 1865篇 |
1999年 | 985篇 |
1998年 | 307篇 |
1997年 | 236篇 |
1996年 | 203篇 |
1995年 | 185篇 |
1994年 | 133篇 |
1993年 | 137篇 |
1992年 | 90篇 |
1991年 | 81篇 |
1990年 | 68篇 |
1989年 | 56篇 |
1988年 | 78篇 |
1987年 | 45篇 |
1986年 | 43篇 |
1985年 | 53篇 |
1984年 | 67篇 |
1983年 | 54篇 |
1982年 | 53篇 |
1981年 | 46篇 |
1980年 | 44篇 |
1979年 | 19篇 |
1978年 | 33篇 |
1977年 | 25篇 |
1976年 | 24篇 |
1975年 | 27篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
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
62.
Paula Vanessa Pedron Oltramari Ricardo de Lima Navarro José Fernando Castanha Henriques Rumio Taga Tania Mary Cestari Guilherme Janson José Mauro Granjeiro 《Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics》2007,104(5):e9-16
OBJECTIVE: The objective of this study was to radiographically quantify bone density and bone height preservation in tooth extraction alveolus filled with xenograft. STUDY DESIGN: The maxillary and mandibular fourth deciduous molars and fourth premolars of 6 minipigs were removed. Randomly, in 3 animals the right side was used as the test side and in the other 3 animals the left side was the test side. Intraoral radiographs were performed to compare the condition at the initial time and 3 months later. Measurements of bone height and bone density were performed using KS300 (Zeiss) software. RESULTS: After 3 months, there was a statistically significant smaller bone height loss for the test group. The test group presented a statistically greater bone density immediately after tooth extraction. However, after 3 months there was no statistically significant difference between the groups. CONCLUSIONS: The results suggest that treatment of postextraction alveolus with xenograft can preserve bone height initially but differences in bone density compared to when no xenograft is used are not sustained. 相似文献
63.
64.
Eric T. Stoopler DMD res Pinto DMD Faizan Alawi DDS Sree Raghavendra DMD Ricardo Boyce Jr. DDS David Porter MD Thomas P. Sollecito DMD 《Special care in dentistry》2004,24(2):65-69
Acute myelogenous leukemia (AMU is a hematologic disorder that is characterized by an abnormal proliferation of immature myeloid cells. Granulocytic sarcomas are clusters of leukemic myeloid cells that may develop as a result of AML. Oral manifestations of AML are common and often involve enlargements of the gingiva and/or mucosal tissue from direct leukemia cell infiltration. We describe the case history of a 50-year-old man who had an ulcera-tive lesion of the oral mucosa that was determined to be a granulocytic sarcoma of AML-M0 subtype. The combination of both the subtype and clinical presentation of the leukemia makes this presentation unusual, and to the best of our knowledge, of a type that has not been previously reported in the literature. 相似文献
65.
Endoscopic Reconstruction of Cranial Base Defects following Endonasal Skull Base Surgery. 总被引:3,自引:0,他引:3
下载免费PDF全文
![点击此处可从《Skull base》网站下载免费的PDF全文](/ch/ext_images/free.gif)
The expanded endonasal approach provides access to the entire ventral skull base for resection of neoplasms involving the skull base and brain. The creation of large defects of the bone and dura endoscopically presents unique reconstructive challenges. A layered reconstruction of the dura with inlay and onlay fascial grafts covered with fat grafts is an effective technique for repair. An intranasal balloon catheter is used to provide counterpressure in the early phase of healing and a lumbar spinal drain is a useful adjunct in patients at increased risk of a cerebrospinal fluid leak. Vascularized flaps may be necessary in some patients receiving radiation therapy. Continued advances in surgical technology and the introduction of new biomaterials will facilitate the reconstruction of skull base defects following endonasal brain surgery. 相似文献
66.
M. I. Manrique-Poyato A. J. Muñoz-Pajares V. Loreto M. D. López-León J. Cabrero J. P. M. Camacho 《Chromosome research》2006,14(6):693-700
We have analysed B chromosome frequency for three consecutive years, B transmission rate at population and individual levels,
clutch size, egg fertility and embryo–adult viability in a natural population of the grasshopper Eyprepocnemis plorans containing two different B chromosome variants, i.e. B2 and B24, the second being derived from the first and having replaced it in nearby populations. From 2002 to 2003 the relative frequency
of both variants changed, although the differences did not reach significance. A mother–offspring analysis showed no significant
effect of any of the two B variants on clutch size, egg fertility or embryo–adult viability, but B24 was more efficiently transmitted than B2 through males from the 2002 season, which explains the observed frequency change. Controlled crosses, at individual level,
showed significant drive through some females for B24 but not for B2, suggesting that this difference in transmission rate might also be important for the substitution process. The analysis
of relative fitness for B2 and B24 carriers for all fitness components, as a whole, showed a significantly better performance of B24-carrying individuals, suggesting that the cumulative effect of these slight differences might contribute to the replacement
of B2 by B24.
Electronic Supplementary Material Supplementary material is available for this article at . 相似文献
67.
Carmen Guillén Ponce María Pilar Garrido López María José Molina Garrido Gema Muñoz Molina Alfredo Carrato 《Clinical & translational oncology》2007,9(1):53-55
Pituitary metastases of solid tumours are infrequent, specially as a first manifestation. When they happen, they are usually
due to breast or lung cancer and are asymptomatic or produce diabetes insipidus. It is very strange that they produce hormonal
deficiency.
We present a case report of a bronchogenic adenocarcinoma in a 65-year-old man which began with panhypopituitarism, diabetes
insipidus and visual alterations. Magnetic resonance imaging revealed a large sellar mass, with clivus infiltration and invading
the right cavernous sinus. The biopsy result was adenocarcinoma metastases from lung cancer. 相似文献
68.
69.
Ricardo J. Wray Jo Ellen Stryker Eric Winer George Demetri Karen M. Emmons 《Journal of cancer education》2007,22(1):21-24
Background. Accepted practices of informed consent often result in suboptimal patient understanding of research studies.Methods. This pilot study aimed to assess trial-specific tailored materials, compared to a widely used generic booklet about clinical
trials, randomly assigned to 118 candidates for cancer clinical trials. Study outcomes were: satisfaction with decision-making;
satisfaction with materials; and subjective understanding of the clinical trial.Results. There were no major differences between groups. Participants rated tailored materials higher as a useful reference.Conclusions. Trial-specific materials hold utility for reference during clinical trials. Studies of informed consent are feasible, although
important factors limit research. 相似文献
70.
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