全文获取类型
收费全文 | 11212篇 |
免费 | 635篇 |
国内免费 | 74篇 |
专业分类
耳鼻咽喉 | 120篇 |
儿科学 | 260篇 |
妇产科学 | 203篇 |
基础医学 | 1404篇 |
口腔科学 | 251篇 |
临床医学 | 821篇 |
内科学 | 3165篇 |
皮肤病学 | 233篇 |
神经病学 | 1114篇 |
特种医学 | 262篇 |
外科学 | 1691篇 |
综合类 | 43篇 |
一般理论 | 1篇 |
预防医学 | 518篇 |
眼科学 | 150篇 |
药学 | 626篇 |
中国医学 | 17篇 |
肿瘤学 | 1042篇 |
出版年
2023年 | 87篇 |
2022年 | 181篇 |
2021年 | 303篇 |
2020年 | 162篇 |
2019年 | 225篇 |
2018年 | 274篇 |
2017年 | 202篇 |
2016年 | 257篇 |
2015年 | 262篇 |
2014年 | 368篇 |
2013年 | 463篇 |
2012年 | 669篇 |
2011年 | 659篇 |
2010年 | 405篇 |
2009年 | 351篇 |
2008年 | 631篇 |
2007年 | 682篇 |
2006年 | 647篇 |
2005年 | 658篇 |
2004年 | 620篇 |
2003年 | 536篇 |
2002年 | 472篇 |
2001年 | 264篇 |
2000年 | 280篇 |
1999年 | 217篇 |
1998年 | 102篇 |
1997年 | 96篇 |
1996年 | 106篇 |
1995年 | 96篇 |
1994年 | 78篇 |
1993年 | 58篇 |
1992年 | 154篇 |
1991年 | 136篇 |
1990年 | 119篇 |
1989年 | 101篇 |
1988年 | 94篇 |
1987年 | 100篇 |
1986年 | 78篇 |
1985年 | 72篇 |
1984年 | 98篇 |
1983年 | 64篇 |
1982年 | 50篇 |
1981年 | 37篇 |
1980年 | 31篇 |
1979年 | 47篇 |
1978年 | 30篇 |
1977年 | 23篇 |
1976年 | 35篇 |
1975年 | 24篇 |
1974年 | 22篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Emmi Helle Aldo Córdova-Palomera Tiina Ojala Priyanka Saha Praneetha Potiny Stefan Gustafsson Erik Ingelsson Michael Bamshad Deborah Nickerson Jessica X. Chong University of Washington Center for Mendelian Genomics Euan Ashley James R. Priest 《Genetic epidemiology》2019,43(2):215-226
Loss of function variants in NOTCH1 cause left ventricular outflow tract obstructive defects (LVOTO). However, the risk conferred by rare and noncoding variants in NOTCH1 for LVOTO remains largely uncharacterized. In a cohort of 49 families affected by hypoplastic left heart syndrome, a severe form of LVOTO, we discovered predicted loss of function NOTCH1 variants in 6% of individuals. Rare or low-frequency missense variants were found in 16% of families. To make a quantitative estimate of the genetic risk posed by variants in NOTCH1 for LVOTO, we studied associations of 400 coding and noncoding variants in NOTCH1 in 1,085 cases and 332,788 controls from the UK Biobank. Two rare intronic variants in strong linkage disequilibrium displayed significant association with risk for LVOTO amongst European-ancestry individuals. This result was replicated in an independent analysis of 210 cases and 68,762 controls of non-European and mixed ancestry. In conclusion, carrying rare predicted loss of function variants in NOTCH1 confer significant risk for LVOTO. In addition, the two intronic variants seem to be associated with an increased risk for these defects. Our approach demonstrates the utility of population-based data sets in quantifying the specific risk of individual variants for disease-related phenotypes. 相似文献
2.
3.
Michele D. Mignogna Stefano Fedele Lucio Lo Russo Lorenzo Lo Muzio 《Journal of oral pathology & medicine》2003,32(4):200-205
BACKGROUND: The recurrent chronic orofacial swelling caused by orofacial granulomatosis (OFG) can cause significant cosmetic and functional problems but can be prevented if the disease is diagnosed early and promptly treated. Although the enlargement of the lips is described to be the most common presenting complaint, the clinical onset of OFG may be characterized by minor associated mucosal and neurological manifestations, making early diagnosis very difficult or, sometimes, merely presumable. PATIENTS AND METHODS: We retrospectively analyzed the clinical manifestations of 19 patients with OFG, who were examined at our institution between 1998 and 2002, in order to determine their initial manifestations and presenting symptoms. RESULTS: A total of 10 patients showed classical recurrent enlargement of the lips (six lower; four upper) as presenting symptom. In the other nine patients, OFG onset was characterized by transient unilateral facial nerve palsy (two cases), intraoral manifestations (two cases), recurrent swelling of the periorbital area (two cases), of the chin (one case), of the zygomatic area (one case), and of the cheeks (one case). CONCLUSION: Our data underlined that OFG onset could be frequently characterized by widely variable, multiform, and temporary clinical findings. Involvement of atypical sites of the orofacial region and presence of single minor manifestations may occur as presenting symptoms, often preceding the development of traditional clinical findings. 相似文献
4.
Accuracy evaluation of image registration and segmentation tools used in conformal treatment planning of prostate cancer. 总被引:1,自引:0,他引:1
Stefania Pallotta Marta Bucciolini Serenella Russo Cinzia Talamonti Talamonti Cinzia Giampaolo Biti 《Computerized medical imaging and graphics》2006,30(1):1-7
Segmentation and registration tools are commonly used in radiotherapy for target and at risk organs localisation. In this work the performances of three different segmentation tools and of a surface matching registration technique, used on computed tomography (CT) and magnetic resonance (MR) images for the treatment planning of conformal prostate carcinoma, are studied. The accuracy of the segmentation and registration tools was evaluated by phantom experiment and on patient data, respectively. A preliminary estimate of MR image distortion was also performed. 相似文献
5.
Low signal intensity on long-repetition-time MR sequences has been observed in deep gray matter structures in patients with multiple sclerosis. This T2 shortening most likely represents a nonspecific degenerative process. We recently observed T2 shortening in the pericentral cortical gray matter and subcortical white matter in a patient with severe multiple sclerosis and we postulate that this represents an additional manifestation of neural degeneration. 相似文献
6.
Summary A case of bilateral congenital pseudarthrosis of the clavicle in a baby boy is described. The patient is fully asymptomatic, and no functional impairment is present. This is probably only the seventh case described of this rare congenital anomaly. 相似文献
7.
Factors affecting aseptic loosening of 4750 total hip arthroplasties: multivariate survival analysis
Barbara Bordini Susanna Stea Manuela De Clerico Sergio Strazzari Antonio Sasdelli Aldo Toni 《BMC musculoskeletal disorders》2007,8(1):69
Background
Total hip arthroplasty is a successful surgery, that fails at a rate of approximately 10% at ten years from surgery. Causes for failure are mainly aseptic loosening of one or both components partially due to wear of articular surfaces and partially to design. The present analysis aimed to identify risk factors and quantify their effects on aseptic failure. 相似文献8.
Francesco Landi Ettore Capoluongo Andrea Russo Graziano Onder Matteo Cesari Paola Lulli Angelo Minucci Marco Pahor Cecilia Zuppi Roberto Bernabei 《Growth hormone & IGF research》2007,17(1):58-66
CONTEXT: Increasing evidences from experimental and human studies suggest that the activity of the growth hormone (GH/insulin-like growth factor-I) axis may contribute to the age-related cognitive decline and poor cognition in late life. OBJECTIVE: The aim of the present study was to evaluate the relationship of total serum free IGF-I and its binding protein-3 with cognitive performance in older persons aged 80 years or older. DESIGN: Data are from baseline evaluation of the ilSIRENTE study (n=353). Cognitive performance was evaluated using five items enclosed in the Minimum Data Set for Home Care assessment form: short-term memory, procedural memory, cognitive skills in daily decision making, verbal expression, comprehension. Free insulin-like growth factor-I (free IGF-I) and IGF-binding protein-3 (IGFBP-3) in blood were measured. Analysis of covariance (ANCOVA) was used to examine the relationship between cognitive impairment and the serum free IGF-I and IGFBP-3 concentrations, after adjustment for potential confounding variables. RESULTS: After adjustment for potential confounders, which included age, gender, education, cerebrovascular disease, ischemic heart disease, congestive heart failure, hypertension, diabetes, depression, Parkinson diseases, thyroid diseases, smoking status, alcohol abuse, body mass index, and number of medications, individuals with verbal expression problems (n=20) and individuals with comprehension problems (n=24) had a significantly lower serum levels of readily dissociable IGF-I than participants without cognitive impairments. The serum IGFBP-3 presented the same behavior of free IGF-I. CONCLUSION: The present study suggests that among old-old subjects living in the community lower levels of total serum free IGF-I and IGFBP-3 are associated with impairment of cognitive performance. This finding suggests that the GH/IGF-I axis may play an important role in the age-related decline of cognitive performance. 相似文献
9.
Molecular cloning and complete nucleotide sequence of galinsoga mosaic virus genomic RNA 总被引:1,自引:0,他引:1
Summary. The complete genomic sequence of galinsoga mosaic virus (GaMV) was determined. The genome consists of 3 803 nucleotides and
has five open reading frames (ORFs). The 5′ ORF (ORF 1) encodes a protein with predicted molecular mass of 23 kDa and readthrough
of its amber stop codon probably yields a 82 kDa protein (ORF 2). ORFs 3 and 4 encode two polypeptides with molecular masses
of 8 and 7 kDa, respectively. ORF 5 encodes the 36 kDa capsid protein. Amino acid sequence comparisons revealed that the nonstructural
proteins encoded by ORFs 1, 3, and 4 were more similar to the corresponding gene products of tobacco necrosis virus, strain
A, than to those of carmoviruses. Conversely, the coat protein was more similar to that of tombusviruses. The readthrough
region of the viral replicase (ORF 2) had high sequence homology with that of carmo-, tombus-, and necroviruses. Computer
analysis of the protein encoded by ORF 1 as well as of the corresponding product of turnip crinkle (TCV) and melon necrotic
spot (MNSV) carmoviruses revealed the presence of a sequence with local hydrophobicity and hydrophobic moment characteristic
of mitochondrial targeting sequence which may explain the origin of the carmovirus-induced multivesicular bodies from mitochondria.
Accepted August 25, 1997 Received June 18, 1997 相似文献
10.
Torasemide, a new loop diuretic, was administered in 9 hospitalized patients with chronic renal failure to treat both arterial hypertension and peripheral edema. The urine of 5 patients was collected over 12-hour periods to assess the long-lasting diuretic activity of torasemide. Torasemide induced a significant decrease in blood pressure and reversion of peripheral edema in all patients without adverse effects. Torasemide is a high-ceiling loop diuretic, useful in correcting extracellular fluid volume expansion in patients with chronic renal failure. 相似文献